When using a sealing material , seams on both sides should have waterproof grassroots , grassroots surface should be necessary processing , the proposed definition should include sealing material covering seal. Here we describe under the sealing material in construction waterproofing application .
A classification and role
Sealing material into shaped and unshaped ( paste ) two kinds . Stereotypes sealing materials including rubber water stop and water swelling rubber seal ; monolithic sealing materials include silicone sealants ,luggage seal polysulfide sealant category , polyurethane sealant, acrylic sealant, butyl-based sealant , modified asphalt sealing paste . Due to space limitations , this article focuses on the construction of monolithic waterproofing sealant application .
Integrity is waterproof layer must have the basic properties that can in reality there are various permeable waterproof layer seam sealing material should be properly applied to these permeable seams , waterproof layer on both sides of the joints are connected together , the sealing material serve as a bridge at the seams , by using a sealing material , with the integrity of the waterproof layer , the joint between the waterproof layer is watertight and airtight have , which is the true purpose of using a sealing material .
Sealing materials should meet two conditions:
( 1 ) shrink freely , fixed length plastic strap seal can adapt to and maintain an effective seal joint displacement amount of deformation ;
( 2 ) joint displacement process does not produce cohesive bond failure and destruction . In the construction waterproofing , the sealing material in the long-term flooding of the state , they should meet these two conditions .
plastic padlock security seals
plastic padlock security seals
2013年10月31日星期四
Introduction of nuclear power shaft seal factory owners
Reactor primary coolant pump ( hereinafter referred to as the main pump ) is the heart of the reactor . Water filling the primary system , the use of dynamic driven main pump gas, before the heap in the open , using the master pump loop temperature reached 280 ℃ open heap condition .
In normal operation, the reactor coolant from the reactor effluent flows through the main channel into the steam generator, the heat is transferred to the secondary circuit water , and then pumped back to the reactor by the main loop through the main pump motor with large flywheel to increase primary pump idle time , maintain proper inertia , ensuring power outage core fuel elements will not be burned.
Qinshan one of the two main pump is a vertical , single suction, Francis , by the end of the pump housing and safety , the rotor components, shaft barrier seals parts, bearing parts, oil system , seal water and cold water system components located . Unit Total height 9.5 m, the reactor coolant water from the bottom of the axial , radial discharge levels from the drive end pump counterclockwise rotation.
Main pump shaft seal is a mechanical seal , the use of three identical hydrodynamic seal in series, the graphite ring material , stationary ring material is tungsten carbide, other static sealing material is EPDM.
Three-stage seal the pressure drop of the system pressure by 40%, 40 %, 20% to allocate , but each system -level design to withstand full pressure . Sealing pressure drop values are assigned at all levels rely on stream -flow device festive controlled leakage flow to achieve the first stage and second stage sealed throttling device composed by two coiled capillary tube , sealed throttling device is the third level rely on a restrictor to achieve.
In all conditions, the shaft truck seal working life of at least 10,000 hours .
In normal operation, the reactor coolant from the reactor effluent flows through the main channel into the steam generator, the heat is transferred to the secondary circuit water , and then pumped back to the reactor by the main loop through the main pump motor with large flywheel to increase primary pump idle time , maintain proper inertia , ensuring power outage core fuel elements will not be burned.
Qinshan one of the two main pump is a vertical , single suction, Francis , by the end of the pump housing and safety , the rotor components, shaft barrier seals parts, bearing parts, oil system , seal water and cold water system components located . Unit Total height 9.5 m, the reactor coolant water from the bottom of the axial , radial discharge levels from the drive end pump counterclockwise rotation.
Main pump shaft seal is a mechanical seal , the use of three identical hydrodynamic seal in series, the graphite ring material , stationary ring material is tungsten carbide, other static sealing material is EPDM.
Three-stage seal the pressure drop of the system pressure by 40%, 40 %, 20% to allocate , but each system -level design to withstand full pressure . Sealing pressure drop values are assigned at all levels rely on stream -flow device festive controlled leakage flow to achieve the first stage and second stage sealed throttling device composed by two coiled capillary tube , sealed throttling device is the third level rely on a restrictor to achieve.
In all conditions, the shaft truck seal working life of at least 10,000 hours .
2013年10月28日星期一
Porous mechanical seal Principle and Application
Car, that ring does not rotate, the spring force, the stationary ring plane static and dynamic sealing rings, so that the fluid medium to be sealed. When the ring rotates, the surface of the stationary ring has many pores, rotating ring and the stationary ring so that the surface pores on the surface of the fluid film formation convergence gap, so that each hole is like a micro power sliding bearings. That is, when the other end surface of the porous surface of the slide, the hole will be generated around the top and the fluid dynamic pressure, which is the fluid dynamic pressure effect. Fluid dynamic pressure bearing capacity depends on sliding speed, viscosity of the medium and the fluid film thickness. These holes generate dynamic pressure effect of the joint action of the result that the two sealing surfaces apart.pull tight plastic seals Since the presence of two fluid film between the seal faces, no direct contact with the two sealing surfaces, the sealing surface between the friction state of fluid friction. Experimental studies have shown that, in the face load and speed are the same, porous mechanical seal ring is always greater than the gap between ordinary mechanical seal the gap between the rings. End load increases, the ordinary mechanical seal ring end gap suddenly decreases, so that direct contact with the end face, film destroyed, so wear and tear. For porous face mechanical seal ring, end load increases, the end clearance is reduced, film increased stiffness, and also happens to be a small gap to minimize leakage to meet stringent mechanical seal leakage requirements, while reducing the sealing surface wear. Therefore, the porous mechanical seal can effectively prolong seal life.
Maximum PV value sealing mechanical seal is to evaluate the operational safety an important indicator of the porous mechanical seal mechanical seal can effectively improve the maximum PV value. Face of the porous ratio of hole depth and diameter to optimize the maximum PV value is about ordinary mechanical seals largest PV value of 2.5 times.
Thus, the porous mechanical seal can effectively improve the sealing parameters to ensure the safe operation of the mechanical seal. Porous mechanical seal has been applied to the petrochemical industry, stainless steel wire ties such as light hydrocarbons and toluene sealing medium at a temperature of 266 ~ 320 ℃, pressure 0.67MPa porous mechanical seal. After six months of actual operation, a satisfactory sealing effect.
Maximum PV value sealing mechanical seal is to evaluate the operational safety an important indicator of the porous mechanical seal mechanical seal can effectively improve the maximum PV value. Face of the porous ratio of hole depth and diameter to optimize the maximum PV value is about ordinary mechanical seals largest PV value of 2.5 times.
Thus, the porous mechanical seal can effectively improve the sealing parameters to ensure the safe operation of the mechanical seal. Porous mechanical seal has been applied to the petrochemical industry, stainless steel wire ties such as light hydrocarbons and toluene sealing medium at a temperature of 266 ~ 320 ℃, pressure 0.67MPa porous mechanical seal. After six months of actual operation, a satisfactory sealing effect.
Comprehensive interpretation of the corners of aluminum doors and windows and sealing the structure to strengthen
After curing epoxy adhesive inelastic, unable to adapt to the form of microseismic, easy crisp and broken, Corner after long-term strength is not enough, will produce cracking, dregs phenomenon. Colloidal slightly foaming during the curing process, expanded, forming metal to metal between the elastic pad, the effective transmission of forces weaken, play a shock, the cushion effect.
With the development of China's construction industry in recent years, aluminum windows and doors have also been developing rapidly. In the rapid development of aluminum windows and doors, while its quality problems are also increasingly prominent. The main questions focused on the quality of their profiles, heat insulation, metal parts and corners of doors and windows and seal strength. Today, we focused on those who use angle code attached to strengthen the corners of aluminum windows and doors often encountered problems with sealing talk about the view.
There are still a lot of people mistakenly believe that: as long as the production of aluminum windows and doors cutting high precision cutting equipment, angle code with the appropriate plus a fixed angle Corner unit, you can make the corners of aluminum windows and doors to achieve the strength and tightness requirements. In fact, most of the use of aluminum windows and doors connecting angle code is to use this process produced. This simple mechanical fixing of the connection is a rigid connection, it is difficult to adapt to windows in the production, transportation, installation, and long-term use encountered by force without being damaged.
First of all, we need to understand the physical properties of aluminum profiles.
Aluminum profiles and other materials, security seals like the existence of any thermal stress. Thermal stress refers to a material change in the temperature-induced stress, typically linear expansion / contraction coefficient.
We can calculate the aluminum alloy in the temperature range of the normal size change, that the linear expansion / shrinkage rate using the following formula: L = L0 (1 + ΑΔT) where: L: length after changing L0: original length, Α: the expansion / contraction coefficient, for aluminum extrusions, in -40 ° C +50 ° C range, the value is 2.4 × 10-5 / ° CΔT: the temperature (Celsius) changes in the value calculation example: aluminum alloy original length of 1 m, the temperature change is +50 ° C-40 ° C = 90 ° CL = 1M (1 +2.4 × 10-5 ° C × 90 ° C) = 1.00216M
That is: 1 meter long aluminum profiles in the 90 ° C temperature variation will produce 2.16MM length variation. Aluminum windows and doors for the corner only rigid connection strength is that this change will have devastating effects, so that doors and windows corner mutual position of the parts disorder or deformation, reflected in the corners of windows and doors undoubtedly fatal flaw . This defect is any bolts or rigid connections Corner machine is no way to make up.
Secondly, in the production of aluminum windows and doors, installation process, due to handling, transport, installation and construction errors when moving, as well as doors and windows installed, aluminum windows and doors to withstand long-term effect of their own weight, withstand window openings, building wall static deformation stress error,truck security seals switching windows, air pressure, environmental impact and frequency of sound waves of varying peak vibration, the vibration can sometimes induce resonance doors, impact on the overall strength of windows and doors.
With the development of China's construction industry in recent years, aluminum windows and doors have also been developing rapidly. In the rapid development of aluminum windows and doors, while its quality problems are also increasingly prominent. The main questions focused on the quality of their profiles, heat insulation, metal parts and corners of doors and windows and seal strength. Today, we focused on those who use angle code attached to strengthen the corners of aluminum windows and doors often encountered problems with sealing talk about the view.
There are still a lot of people mistakenly believe that: as long as the production of aluminum windows and doors cutting high precision cutting equipment, angle code with the appropriate plus a fixed angle Corner unit, you can make the corners of aluminum windows and doors to achieve the strength and tightness requirements. In fact, most of the use of aluminum windows and doors connecting angle code is to use this process produced. This simple mechanical fixing of the connection is a rigid connection, it is difficult to adapt to windows in the production, transportation, installation, and long-term use encountered by force without being damaged.
First of all, we need to understand the physical properties of aluminum profiles.
Aluminum profiles and other materials, security seals like the existence of any thermal stress. Thermal stress refers to a material change in the temperature-induced stress, typically linear expansion / contraction coefficient.
We can calculate the aluminum alloy in the temperature range of the normal size change, that the linear expansion / shrinkage rate using the following formula: L = L0 (1 + ΑΔT) where: L: length after changing L0: original length, Α: the expansion / contraction coefficient, for aluminum extrusions, in -40 ° C +50 ° C range, the value is 2.4 × 10-5 / ° CΔT: the temperature (Celsius) changes in the value calculation example: aluminum alloy original length of 1 m, the temperature change is +50 ° C-40 ° C = 90 ° CL = 1M (1 +2.4 × 10-5 ° C × 90 ° C) = 1.00216M
That is: 1 meter long aluminum profiles in the 90 ° C temperature variation will produce 2.16MM length variation. Aluminum windows and doors for the corner only rigid connection strength is that this change will have devastating effects, so that doors and windows corner mutual position of the parts disorder or deformation, reflected in the corners of windows and doors undoubtedly fatal flaw . This defect is any bolts or rigid connections Corner machine is no way to make up.
Secondly, in the production of aluminum windows and doors, installation process, due to handling, transport, installation and construction errors when moving, as well as doors and windows installed, aluminum windows and doors to withstand long-term effect of their own weight, withstand window openings, building wall static deformation stress error,truck security seals switching windows, air pressure, environmental impact and frequency of sound waves of varying peak vibration, the vibration can sometimes induce resonance doors, impact on the overall strength of windows and doors.
2013年10月27日星期日
Way to achieve zero leakage seals
Pros and cons of two-way seal can withstand radial loads and ensure bi-directional sealing performance. The seal is mainly used for fluid delivery systems, including a variety of medical and dental equipment . With 60 years experience in the production of indicative seals Minnesota Rubber provides bidirectional seal custom design .
In order to achieve zero leakage , Minnesota designed a special rubber lip seals , the sealing lip on one side exposed to the pressure in the positive direction , the other side in the opposite direction to withstand stress. Under pressure , the sealing lip of the seal to close the sealing surface and ensure that the liquid does not leak .
Excellent design , the correct choice of materials and precision manufacturing process for these lip seals deliver the best performance. For medical applications , Minnesota Rubber will choose special material, to ensure the final product low extractables , with most intravenous (IV) fluid system compatibility.
Lip seal size is also an important factor in sealing applications . The sealing member can be reduced smaller possibility of leakage . Minnesota Rubber can design and manufacture a variety of small size meter seals. For example figure parts, maximum diameter of 0.346 inches (8.788mm), an inner diameter of 0.140 inches (3.556mm), a height of 0.145 inches (3.683mm). Tolerance control : ID + / -0.004 inch (0.102mm), sealing surface diameter + / -0.005 inch (0.127mm), seal height + / -0.005 inches (0.127mm). Minnesota Rubber transfer molding using advanced technology and production equipment to ensure dimensional accuracy and product quality parts .
In order to achieve zero leakage , Minnesota designed a special rubber lip seals , the sealing lip on one side exposed to the pressure in the positive direction , the other side in the opposite direction to withstand stress. Under pressure , the sealing lip of the seal to close the sealing surface and ensure that the liquid does not leak .
Excellent design , the correct choice of materials and precision manufacturing process for these lip seals deliver the best performance. For medical applications , Minnesota Rubber will choose special material, to ensure the final product low extractables , with most intravenous (IV) fluid system compatibility.
Lip seal size is also an important factor in sealing applications . The sealing member can be reduced smaller possibility of leakage . Minnesota Rubber can design and manufacture a variety of small size meter seals. For example figure parts, maximum diameter of 0.346 inches (8.788mm), an inner diameter of 0.140 inches (3.556mm), a height of 0.145 inches (3.683mm). Tolerance control : ID + / -0.004 inch (0.102mm), sealing surface diameter + / -0.005 inch (0.127mm), seal height + / -0.005 inches (0.127mm). Minnesota Rubber transfer molding using advanced technology and production equipment to ensure dimensional accuracy and product quality parts .
Mechanical seal on the pump shaft
Compare mechanical seals and packing , mechanical seal has reliable sealing , long life, low power consumption , the use of a wide range of advantages. Part of the early failure of the mechanical waterproof labels life is short, the main problem is the lack of design and manufacturing , often due to improper selection , spare parts of inferior quality , reasonable friction material selection , installation and maintenance shall not be law , sealing causes poor water quality . To extend the life of mechanical seals , need to design , manufacture, maintenance and use of all aspects of work together.
Mechanical seal design and modeling must be combined with the actual production situation , try to use reliable sealing, long-lived static friction materials and seal material . If double mechanical seal contacts the inner end of the media , in order to use corrosion resistant materials based ; does not contact the outer end of the media , in order to choose a good sealing reliability based materials , such as WC rubber rings , etc., are not necessarily consistent pursuit of inner and outer ends selection , both to reduce costs , but also increase the sealing reliability.
Mechanical seal parts machining quality must be strict requirements, specifications and maintenance procedures must be particularly set mechanical seal installation and use of technical requirements, so that rule-based workers .
Mechanical seal during use , is not necessarily a little on the high amount of leakage must overhaul. Sometimes after a period of time to run into the sealing surface of the dirt washed away , sealing water clean, running- friction , the temperature deformation eliminated, leakage will be significantly decreased. For double mechanical seal ,plastic seals as long as they secure pressure , they can test for a period longer overhaul.
Mechanical seal design and modeling must be combined with the actual production situation , try to use reliable sealing, long-lived static friction materials and seal material . If double mechanical seal contacts the inner end of the media , in order to use corrosion resistant materials based ; does not contact the outer end of the media , in order to choose a good sealing reliability based materials , such as WC rubber rings , etc., are not necessarily consistent pursuit of inner and outer ends selection , both to reduce costs , but also increase the sealing reliability.
Mechanical seal parts machining quality must be strict requirements, specifications and maintenance procedures must be particularly set mechanical seal installation and use of technical requirements, so that rule-based workers .
Mechanical seal during use , is not necessarily a little on the high amount of leakage must overhaul. Sometimes after a period of time to run into the sealing surface of the dirt washed away , sealing water clean, running- friction , the temperature deformation eliminated, leakage will be significantly decreased. For double mechanical seal ,plastic seals as long as they secure pressure , they can test for a period longer overhaul.
2013年10月26日星期六
Mechanical shaft seal with them about
( 1 ) When the mechanical seal pressure medium, the pressure medium due to the end face than the pressure of its adaptation range is exceeded , will lead to film damage , causing heating and abrasion ; high friction deformation easy to make and fragmentation , so that the machine seal failure. Required to work under high friction material must have sufficient stiffness and strength , must be considered carbide , ceramic , ceramic spraying pressure and both high strength and stiffness of the material.
( 2 ) In the case of high- speed , linear velocity as the mechanical seal , the sealing surface to increase the friction heat and wear , the friction material should be a good thermal conductivity low coefficient of friction ceramic leaching copper and graphite .
( 3 ) When the mechanical seal in a hot environment , if not handled properly prone to the aging of rubber , part of the deformation , so that the mechanical seal leakage should be used in high-temperature materials, such as sintered alumina ceramic ( alumina ceramic ) , heap solder alloy and so on.
Machine graphite stationary ring quality does not meet the design requirements
Design requirements resin impregnated graphite stationary ring , but have a certain immersion depth. Sometimes impregnated graphite stationary ring is not deep enough , fixed length plastic strap seal that is impregnated layer remaining after machining rarely ; design requirements face some finish, but often fail to meet requirements spare finish ; design requirements purity graphite texture , and a certain hardness, and spare parts tend to have hard spots , hardness is not enough and so on. Resulting graphite wear very serious.
Improper selection of spring pressure machine
Mechanical seal primary seal point - dynamic seal point , is perpendicular to the axis of rotational movement of the ring end face and the end faces of the stationary ring by bonding together . The sealing end face of the spring clamping force is generated by the spring pressure , the low pressure seal faces is to start , run and stop lamination case always maintain a good prerequisite sealed state . When the seal face wear , by the spring pressure to overcome the friction of the shaft seal to ensure that ring moved axially face wear compensation , ensure the seal .
Since spring pressure value directly affects the size sealing reliability , such as spring pressure is too large ,wire seals the sealing surface overextended , increased wear and tear ; spring pressure value is too small , not well fit the sealing surface , the spring force to resist not within the gas medium pressure or face wear not compensated , resulting in mechanical seal leakage . Therefore, a reasonable choice of spring pressure value is the key to sealing reliability . Spring pressure is not enough, take the following two methods to eliminate leakage : ( a ) in the ring behind padded to compensate for the spring force . ( 2 ) with a spatula and abrasive scraping , sanding sealed chamber and the spring seat and "V" -ring with the Department , so that the spring force acting on the friction pairs tightly closed.
( 2 ) In the case of high- speed , linear velocity as the mechanical seal , the sealing surface to increase the friction heat and wear , the friction material should be a good thermal conductivity low coefficient of friction ceramic leaching copper and graphite .
( 3 ) When the mechanical seal in a hot environment , if not handled properly prone to the aging of rubber , part of the deformation , so that the mechanical seal leakage should be used in high-temperature materials, such as sintered alumina ceramic ( alumina ceramic ) , heap solder alloy and so on.
Machine graphite stationary ring quality does not meet the design requirements
Design requirements resin impregnated graphite stationary ring , but have a certain immersion depth. Sometimes impregnated graphite stationary ring is not deep enough , fixed length plastic strap seal that is impregnated layer remaining after machining rarely ; design requirements face some finish, but often fail to meet requirements spare finish ; design requirements purity graphite texture , and a certain hardness, and spare parts tend to have hard spots , hardness is not enough and so on. Resulting graphite wear very serious.
Improper selection of spring pressure machine
Mechanical seal primary seal point - dynamic seal point , is perpendicular to the axis of rotational movement of the ring end face and the end faces of the stationary ring by bonding together . The sealing end face of the spring clamping force is generated by the spring pressure , the low pressure seal faces is to start , run and stop lamination case always maintain a good prerequisite sealed state . When the seal face wear , by the spring pressure to overcome the friction of the shaft seal to ensure that ring moved axially face wear compensation , ensure the seal .
Since spring pressure value directly affects the size sealing reliability , such as spring pressure is too large ,wire seals the sealing surface overextended , increased wear and tear ; spring pressure value is too small , not well fit the sealing surface , the spring force to resist not within the gas medium pressure or face wear not compensated , resulting in mechanical seal leakage . Therefore, a reasonable choice of spring pressure value is the key to sealing reliability . Spring pressure is not enough, take the following two methods to eliminate leakage : ( a ) in the ring behind padded to compensate for the spring force . ( 2 ) with a spatula and abrasive scraping , sanding sealed chamber and the spring seat and "V" -ring with the Department , so that the spring force acting on the friction pairs tightly closed.
Rubber water-stop installation and construction methods and precautions
Rubber Sealing Strip is in the concrete casting process where some or all of the pouring buried in concrete, the concrete number of pointed stones and sharp steel head , the plastic and rubber tear strength than the tensile strength 3-5 times , water stop once it has been punctured or torn ,metal seal without a great outside external gap will widen , so the water stop position and concrete pouring process, should pay attention to positioning methods and pouring pressure to avoid sealing band is punctured.
1 waterstops shall prolonged outdoor exposure, to prevent rain , not with polluting chemical substances. 2 in the transport and construction, to prevent mechanical , steel damage water stop .
(2) the construction process, the water stop must be firmly secured to prevent displacement occurs in the pouring of concrete , waterstops in concrete to ensure the correct position .
3 Fixed waterstops methods are: use of additional reinforced fixed ; special fixtures ; wire and template fixed For perforation, the only election in the water stop edge of the installation shall not damage other parts.
4 user orders should be based engineering structures, calculate the length of the product design drawings , drawings shaped structure should be explained , as far as possible water stop at the factory will connect into a whole, for the connection of the site ,pull tight straps can be electrically heated plate vulcanizing adhesive together or cold adhesive ( rubber water ) or welded ( plastic water stop ) approach.
1 waterstops shall prolonged outdoor exposure, to prevent rain , not with polluting chemical substances. 2 in the transport and construction, to prevent mechanical , steel damage water stop .
(2) the construction process, the water stop must be firmly secured to prevent displacement occurs in the pouring of concrete , waterstops in concrete to ensure the correct position .
3 Fixed waterstops methods are: use of additional reinforced fixed ; special fixtures ; wire and template fixed For perforation, the only election in the water stop edge of the installation shall not damage other parts.
4 user orders should be based engineering structures, calculate the length of the product design drawings , drawings shaped structure should be explained , as far as possible water stop at the factory will connect into a whole, for the connection of the site ,pull tight straps can be electrically heated plate vulcanizing adhesive together or cold adhesive ( rubber water ) or welded ( plastic water stop ) approach.
2013年10月24日星期四
Work requirements for seals inventory
1 hardening (aging ) - One seal leak because its temperature material is hardened , when the hardness is too high ,pull tight plastic seals the sealing member can not be filled and with a gap between the parts , it will leak .
(2) Wear - wear of the seal surface of the part involved with the finish , velocity and transmission media , different sealing materials, adapted to different velocity .
3 Extrusion - when the seal to put too much pressure will be squeezed into the metal gap , damaged seals and cause leakage , this situation involves seals of their hardness and metal gap is too large, if in the design , selection , processed or handled properly installed , there will be out of damage.
4 Corrosion - the situation is manifested seals soften even dissolve , because seals invaded by the media , the choice of material error. If the aqueous or solvent media paying particular attention.
5 General seal according to the temperature ,strap seals velocity , pressure, and material can be used for the following simple classification ( for reference only ) : Temperature ratings apply material velocity pressure levels for materials for materials 110 ℃ nitrile rubber / PU 0.5 M / S nitrile rubber 200kg / cm2 with the hardness and design 200 ℃ Viton 0.6 M / S PU 400kg / cm2 with the hardness and design 260 ℃ PTFE 14 M / S PTFE 700kg / cm2 with the hardness and design more about "Hydraulic seals "
(2) Wear - wear of the seal surface of the part involved with the finish , velocity and transmission media , different sealing materials, adapted to different velocity .
3 Extrusion - when the seal to put too much pressure will be squeezed into the metal gap , damaged seals and cause leakage , this situation involves seals of their hardness and metal gap is too large, if in the design , selection , processed or handled properly installed , there will be out of damage.
4 Corrosion - the situation is manifested seals soften even dissolve , because seals invaded by the media , the choice of material error. If the aqueous or solvent media paying particular attention.
5 General seal according to the temperature ,strap seals velocity , pressure, and material can be used for the following simple classification ( for reference only ) : Temperature ratings apply material velocity pressure levels for materials for materials 110 ℃ nitrile rubber / PU 0.5 M / S nitrile rubber 200kg / cm2 with the hardness and design 200 ℃ Viton 0.6 M / S PU 400kg / cm2 with the hardness and design 260 ℃ PTFE 14 M / S PTFE 700kg / cm2 with the hardness and design more about "Hydraulic seals "
Polysulfide sealant Characteristics and Application of Technology
With China 's rapid economic and technological development of large-scale water conservancy project, the construction of high-rise buildings , aerospace engineering development and so need special properties of elastic adhesive sealant for joints , security seals sealing materials. According to reports , China's output of this sealant has reached 4 to 5 million tons, and formed a polysulfide , acrylic , silicone and polyurethane sealants as the main industries.
Polysulfide sealant is a polysulfide rubber (HS-(C2H4)-O-CH2-O-C2H4-SS) n-C2H4-O-CH2-O-C2H4-SH) -based agent , a plasticizer , reinforcing agents , curing agents made of high-grade sealing materials. Because liquid polysulfide rubber polymer main chain containing "S" atom , forming -CS,-SS- chain and is saturated, which made the polysulfide sealant has excellent oil resistance , solvent resistance, aging , acid base properties, and heat, water , low permeability , good elasticity, for metal and nonmetal have a high bond strength. Mainly used for insulating glass sealing , high-rise building roof slab waterproofing and sealing subways, tunnels, sewage treatment plants, airport runways, large water conservancy waterproof seal joints . Therefore, there are broad application prospects.
Thiokol in 1929 successfully developed by the American company , in a solid state. Until 1943 improved synthesis process , made with a thiol end group of the liquid polysulfide rubber , have a rapid development. Since this polymer with various peroxides , oxide to cure at room temperature to form elastomers , thus expanding the range of its use .
Abroad in the 1960s polysulfide sealant in the automotive, shipbuilding , petrochemical and sealed waterproof construction work and other aspects are given a wide range of applications . Thiokol in our research work started late, until 1958 after the establishment of Jinxi Chemical Research Institute considered on track. Late 1970s early 1980s with the development of high-rise buildings , along with the rise of aluminum doors and windows was promoted polysulfide sealant waterproof seal in construction engineering applications .
The world production of liquid polysulfide rubber , the United States 20,000 tons / year, Germany 8000 tons / year, Japan 5,000 tons / year, Russia 3500 tons / year, Western Europe, about 2,000 tons / year. Chemical Research Institute of Jinxi only 500 tons / year scale devices can not meet the market demand, at present most of our imports from Japan , security seals the annual import volume of 1500 ... 1800 tons ; production of polysulfide sealant has reached more than 8,000 tons .
Polysulfide sealant is a polysulfide rubber (HS-(C2H4)-O-CH2-O-C2H4-SS) n-C2H4-O-CH2-O-C2H4-SH) -based agent , a plasticizer , reinforcing agents , curing agents made of high-grade sealing materials. Because liquid polysulfide rubber polymer main chain containing "S" atom , forming -CS,-SS- chain and is saturated, which made the polysulfide sealant has excellent oil resistance , solvent resistance, aging , acid base properties, and heat, water , low permeability , good elasticity, for metal and nonmetal have a high bond strength. Mainly used for insulating glass sealing , high-rise building roof slab waterproofing and sealing subways, tunnels, sewage treatment plants, airport runways, large water conservancy waterproof seal joints . Therefore, there are broad application prospects.
Thiokol in 1929 successfully developed by the American company , in a solid state. Until 1943 improved synthesis process , made with a thiol end group of the liquid polysulfide rubber , have a rapid development. Since this polymer with various peroxides , oxide to cure at room temperature to form elastomers , thus expanding the range of its use .
Abroad in the 1960s polysulfide sealant in the automotive, shipbuilding , petrochemical and sealed waterproof construction work and other aspects are given a wide range of applications . Thiokol in our research work started late, until 1958 after the establishment of Jinxi Chemical Research Institute considered on track. Late 1970s early 1980s with the development of high-rise buildings , along with the rise of aluminum doors and windows was promoted polysulfide sealant waterproof seal in construction engineering applications .
The world production of liquid polysulfide rubber , the United States 20,000 tons / year, Germany 8000 tons / year, Japan 5,000 tons / year, Russia 3500 tons / year, Western Europe, about 2,000 tons / year. Chemical Research Institute of Jinxi only 500 tons / year scale devices can not meet the market demand, at present most of our imports from Japan , security seals the annual import volume of 1500 ... 1800 tons ; production of polysulfide sealant has reached more than 8,000 tons .
2013年10月23日星期三
Impact of construction machinery hydraulic oil quality factor
The quality of hydraulic oil , not only affects the normal operation of construction machinery , id cable ties and may cause serious damage to the hydraulic system components . Now summarize the work practice in the absence of dedicated instrumentation several cases , simple identification of hydraulic oil quality.
1 water . The amount of oil in the water content of water in accordance with GB GB/T1118.1-94 technical standards, and tested its quality indicators should be not more than traces if excessive moisture in the oil , it must be replaced ; Otherwise , not only will damage the bearings , but also to rusty steel surface , thus the hydraulic oil emulsion , deterioration and a precipitate , hinder thermal cooler , affect the valve , reducing the active area of a filter , increasing the abrasive action of the oil .
( A ) visual method : If the oil is milky white turbid , then the oil contains large amounts of water .
( 2 ) combustion method: using a clean, dry cotton or tissue stained with a little oil to be detected , then the use of fire to ignite . If you find " crackling" sound or flash the burst phenomenon , then the oil contains more moisture
(2) oxidation. General construction machinery hydraulic oil operating temperature of 30-80 ℃, hydraulic oil temperature is closely related to their work life , experience tells us that when working oil temperature above 60 ℃ , each additional 8 ℃, oil life is halved , that is the life of the oil 90 ℃ 60 ℃ about 10% of oil , because the oil is oxidized. Oxygen and hydrocarbon oils reacting the oil slowly oxidized, black color , viscosity increase , and finally could not be serious enough to oxide dissolved in the oil , and brown mucus layer deposition to somewhere in the system , easily blocked element in the control oil passages , so that ball , valve, hydraulic pump piston wear increased , affecting the normal operation of the system . Acid oxidation also cause corrosion . Slowly began to carry out the oxidation process , when it reaches a certain stage, the oxidation rate will suddenly accelerated, will follow the sudden increase in viscosity , resulting in working oil temperature , the oxidation process faster , the accumulated sediment and acid will be more Finally the oil can not be reused.
3 impurities. Impurities can not only wear the moving parts , but once they are stuck in the spool or other deputy campaign , you will affect the normal operation of the whole system , Fixed Length plastic seals cause the machine to malfunction.
4 air . If the hydraulic oil containing gas , when the bubble wall and the overflow will impact the formation of cavitation generated elements , so that the system does not work , a little longer will result in component damage .
5 . Chemical reaction. Tank shall be cleaned of paint , etc., can cause chemical changes in the oil .
1 water . The amount of oil in the water content of water in accordance with GB GB/T1118.1-94 technical standards, and tested its quality indicators should be not more than traces if excessive moisture in the oil , it must be replaced ; Otherwise , not only will damage the bearings , but also to rusty steel surface , thus the hydraulic oil emulsion , deterioration and a precipitate , hinder thermal cooler , affect the valve , reducing the active area of a filter , increasing the abrasive action of the oil .
( A ) visual method : If the oil is milky white turbid , then the oil contains large amounts of water .
( 2 ) combustion method: using a clean, dry cotton or tissue stained with a little oil to be detected , then the use of fire to ignite . If you find " crackling" sound or flash the burst phenomenon , then the oil contains more moisture
(2) oxidation. General construction machinery hydraulic oil operating temperature of 30-80 ℃, hydraulic oil temperature is closely related to their work life , experience tells us that when working oil temperature above 60 ℃ , each additional 8 ℃, oil life is halved , that is the life of the oil 90 ℃ 60 ℃ about 10% of oil , because the oil is oxidized. Oxygen and hydrocarbon oils reacting the oil slowly oxidized, black color , viscosity increase , and finally could not be serious enough to oxide dissolved in the oil , and brown mucus layer deposition to somewhere in the system , easily blocked element in the control oil passages , so that ball , valve, hydraulic pump piston wear increased , affecting the normal operation of the system . Acid oxidation also cause corrosion . Slowly began to carry out the oxidation process , when it reaches a certain stage, the oxidation rate will suddenly accelerated, will follow the sudden increase in viscosity , resulting in working oil temperature , the oxidation process faster , the accumulated sediment and acid will be more Finally the oil can not be reused.
3 impurities. Impurities can not only wear the moving parts , but once they are stuck in the spool or other deputy campaign , you will affect the normal operation of the whole system , Fixed Length plastic seals cause the machine to malfunction.
4 air . If the hydraulic oil containing gas , when the bubble wall and the overflow will impact the formation of cavitation generated elements , so that the system does not work , a little longer will result in component damage .
5 . Chemical reaction. Tank shall be cleaned of paint , etc., can cause chemical changes in the oil .
Mechanical seals and hydraulic seals difference
People are generally very difficult to distinguish between the mechanical seals and hydraulic seals, often thought it was the same object.
First, talk about mechanical seals and hydraulic seals: Wikipedia
Mechanical seals are precision , structure is more complex mechanical component of the foundation , a variety of pumps, reaction synthesis reactor, turbine compressor , submersible motors and other key components of the device . Its sealing performance and service life depends on many factors , such as selection, the accuracy of the machine , the correct use of the installation .
Hydraulic seal pressure demands to have a combination of surface finish , use more rubber sealing element , through the seal to achieve local deformation of the sealing effect .
Second, the mechanical seals and hydraulic seals Category
Mechanical seal Model: cartridge seals series, light mechanical seal series , heavy mechanical seal series
Hydraulic seals : lip seals , V -ring , U -ring , Y -ring , YX -ring seals and hydraulic cylinder seals commonly used combination is mainly bud -ring cell to circle and Lancaster closure .
Third, how to choose the seals
Seals in the purchase of maintenance ,numbered security seals most users will be according to the sample size and color to buy, this will only increase the difficulty of purchasing , but not necessarily be able to select the appropriate product. The following procedures are recommended to improve the accuracy of purchase seals :
1 the direction of movement - first determine the location of the sealing member movement direction , such reciprocating , rotary , screw or fixed .
2 Sealed focus - such as deciding the point of activity in the inner diameter of the rod seal or activity point is at the outer diameter of the piston seal.
3 Temperature Class - Instructions for use machinery from the factory to inspect or assess the actual working environment temperature, determine the required use of materials . For a description of the temperature level of production users can refer to the following precautions .
4 pressure levels - from factory machinery access to the relevant data for use , or by observing the original seals and structural inference softness working pressure rating, a description of the relevant pressure level production users can refer to the following precautions .
5 size - most users will by used to buy old samples ,security ties but seals in use for some time, will be the temperature, pressure and wear and tear and other factors significantly affect its original size, press the select sample only as a reference , a better approach is to measure the location of the metal seal tank size , accuracy will be higher .
First, talk about mechanical seals and hydraulic seals: Wikipedia
Mechanical seals are precision , structure is more complex mechanical component of the foundation , a variety of pumps, reaction synthesis reactor, turbine compressor , submersible motors and other key components of the device . Its sealing performance and service life depends on many factors , such as selection, the accuracy of the machine , the correct use of the installation .
Hydraulic seal pressure demands to have a combination of surface finish , use more rubber sealing element , through the seal to achieve local deformation of the sealing effect .
Second, the mechanical seals and hydraulic seals Category
Mechanical seal Model: cartridge seals series, light mechanical seal series , heavy mechanical seal series
Hydraulic seals : lip seals , V -ring , U -ring , Y -ring , YX -ring seals and hydraulic cylinder seals commonly used combination is mainly bud -ring cell to circle and Lancaster closure .
Third, how to choose the seals
Seals in the purchase of maintenance ,numbered security seals most users will be according to the sample size and color to buy, this will only increase the difficulty of purchasing , but not necessarily be able to select the appropriate product. The following procedures are recommended to improve the accuracy of purchase seals :
1 the direction of movement - first determine the location of the sealing member movement direction , such reciprocating , rotary , screw or fixed .
2 Sealed focus - such as deciding the point of activity in the inner diameter of the rod seal or activity point is at the outer diameter of the piston seal.
3 Temperature Class - Instructions for use machinery from the factory to inspect or assess the actual working environment temperature, determine the required use of materials . For a description of the temperature level of production users can refer to the following precautions .
4 pressure levels - from factory machinery access to the relevant data for use , or by observing the original seals and structural inference softness working pressure rating, a description of the relevant pressure level production users can refer to the following precautions .
5 size - most users will by used to buy old samples ,security ties but seals in use for some time, will be the temperature, pressure and wear and tear and other factors significantly affect its original size, press the select sample only as a reference , a better approach is to measure the location of the metal seal tank size , accuracy will be higher .
2013年10月22日星期二
Condensate pump shaft seal rehabilitation programs
Cancellation packing seal, no leakage lossless transformation of a single cartridge mechanical seal face .
Transformation of the condensate pump range:
a) The structure of the pump itself, without any changes , retaining the original sleeve , but to ensure sleeve diameter size φ120-0.04-0.08mm, outer surface roughness Ra of less than 6.3μm;
b) The outer face of the gland packing chamber by the two bolt holes increased to 4 , in order to ensure the mechanical padlock seal gland installation force uniform ;
c) cancel the filler , watershed ring, packing gland ;
d) retain the original outer loop piping system, which is only used at startup , normal operation can be shut down packing chamber cooling water ;
e) from the mechanical seal and flush mouth then a nominal diameter of 8 mm tube into the original relief holes , and install the valve control. 3 swing and ran on the mechanical shaft seal of LDTN type condensate pump for the vertical suspension mode , the pump and motor by the motor rotor weight borne Thrust above . Normal conditions , the upper and lower motor bearings and bearing fluorine resin condensate pump rotor pump only play the role of radial positioning , there is damage to the mechanical seal swing mainly radial and axial movement of the swing . If the radial and axial movement of the swing beyond the mechanical seal to allow beating range, it will damage the mechanical Fixed Length plastic seal. The following may occur for condensate pump two most harsh conditions the greatest impact on the mechanical seal , one is in the motor pump and motor shaft bearings as a fulcrum for the conical lower swing ; another is based on the lower bearing motor and pump heads fluorine resin bearings as a fulcrum for the arc-shaped swing.
Transformation of the condensate pump range:
a) The structure of the pump itself, without any changes , retaining the original sleeve , but to ensure sleeve diameter size φ120-0.04-0.08mm, outer surface roughness Ra of less than 6.3μm;
b) The outer face of the gland packing chamber by the two bolt holes increased to 4 , in order to ensure the mechanical padlock seal gland installation force uniform ;
c) cancel the filler , watershed ring, packing gland ;
d) retain the original outer loop piping system, which is only used at startup , normal operation can be shut down packing chamber cooling water ;
e) from the mechanical seal and flush mouth then a nominal diameter of 8 mm tube into the original relief holes , and install the valve control. 3 swing and ran on the mechanical shaft seal of LDTN type condensate pump for the vertical suspension mode , the pump and motor by the motor rotor weight borne Thrust above . Normal conditions , the upper and lower motor bearings and bearing fluorine resin condensate pump rotor pump only play the role of radial positioning , there is damage to the mechanical seal swing mainly radial and axial movement of the swing . If the radial and axial movement of the swing beyond the mechanical seal to allow beating range, it will damage the mechanical Fixed Length plastic seal. The following may occur for condensate pump two most harsh conditions the greatest impact on the mechanical seal , one is in the motor pump and motor shaft bearings as a fulcrum for the conical lower swing ; another is based on the lower bearing motor and pump heads fluorine resin bearings as a fulcrum for the arc-shaped swing.
Eliminate cavitation pump inlet measures
( A ) to improve the level of pump cavitation performance , cavitation field devices to meet performance requirements .
( 2 ) field test equipment required to pump cavitation performance level match.
( 3 ) on-site installation and regulate working conditions and create favorable conditions to give the pump numbered security seals .
Measures to eliminate vibration pump
( 1 ) pump assembly process, in strict accordance with standards and procedures to perform, to eliminate vibration source .
( 2 ) pumps, motors , base, on-site piping and other auxiliary equipment installed in the field , to strictly eliminate vibration sources.
( 3 ) on-site production ,tamper seal labels operation, maintenance , adjustment, strictly, to eliminate vibration source .
( 2 ) field test equipment required to pump cavitation performance level match.
( 3 ) on-site installation and regulate working conditions and create favorable conditions to give the pump numbered security seals .
Measures to eliminate vibration pump
( 1 ) pump assembly process, in strict accordance with standards and procedures to perform, to eliminate vibration source .
( 2 ) pumps, motors , base, on-site piping and other auxiliary equipment installed in the field , to strictly eliminate vibration sources.
( 3 ) on-site production ,tamper seal labels operation, maintenance , adjustment, strictly, to eliminate vibration source .
2013年10月11日星期五
More teeth difference cycloid gear pump Knowledge Overview
More teeth difference cycloid gear pump ( also known as small teeth cycloid pump ) is 80 years abroad developed a new cycloidal gear pumps, slashing at the top of its non- mining Chuan complete isometric short Epicycloid curve for cycloid ( pinion ) tooth profile .plastic seals With phase conjugation using adjacent circular cross gear tooth root and the tooth after slashing the top of the arc for a tooth profile . There are two tooth difference , three teeth difference cycloid gear pump . Compared with the ordinary cycloid pump , it has a flow pulsation , large displacement , etc. .
Ordinary internal gear pump and multi- pump teeth difference cycloid tooth profile is very similar to the composition , such as tooth profile curve equation , the choice of the design parameters have similar laws Fixed Length plastic seal .
More teeth difference cycloid gearing major river in the hydraulic system of hydraulic pumps and hydraulic motors can also be used for planetary transmission .
Ordinary internal gear pump and multi- pump teeth difference cycloid tooth profile is very similar to the composition , such as tooth profile curve equation , the choice of the design parameters have similar laws Fixed Length plastic seal .
More teeth difference cycloid gearing major river in the hydraulic system of hydraulic pumps and hydraulic motors can also be used for planetary transmission .
Re- heat boiler tube wall comb through modification of the sealing plate
Comb-shaped sealing plate is modified reheat type folding comb sealing plate to locate the seal plate (12Cr1MoV, δ8), positioning the sealing plate processing when a uniform length and width of the plate after marking , according to the reheater pipe diameter (D64mm) drilled hole , and then follow the protective casing diameter (D68mm) machined counterbore depth of 3mm . Reheater embedded in the protective sleeve by positioning the sealing plate , to ensure the pitch between the tubes , reducing the swing tube rows . Meanwhile , this welded structure is simple, convenient , to further improve the welding quality, avoid the folding -type comb -shaped seal plate complex produced by processing and assembly difficulties deviation , thereby preventing the seal lower quality weld .
Installation of protective casing protective casing installation transition purposes : ( 1 ) casing material and its internal wall pipe of the same material , in order to ensure that the work of the tube with protective sleeve seam welded joints using the same kind of steel , will be transferred to the dissimilar steel welded joints with protective sleeve positioned between the seal plate welds , improved wall pipe work weld crack resistance ; ( 2 ) protection tube wall thickness thinner than the reheater tubes , which specifications for D68mm × 3mm, reducing its structural rigidity makes sealing welding deformation transferred to the casing ,indicative seals eliminating the formation of geometric stress concentration points , improved wall pipe work weld the force .
Construction should pay attention to the problems of access to the site reheater tube wall spectrum in addition to a 100% and 100% visual inspection , but also deal fillet weld pipe through the wall set at 100 % of the magnetic memory testing , to prevent unqualified ( exist melting wear , weld defects such as abnormal stress concentration ) pipe is used.
Note wall pipe positioning in the high roof pitch , the tube is in the process of looking for prohibited the use of flame cutting tools, in order to avoid the flame burn or cut high roof inside reheater tubes . Guaranteed replacement wall pipe before and after the reheater tubes mounted side elevation of the same, to prevent the tube rows down and obscure corner wall tube row spacing becomes smaller , resulting reheater appear swollen outer pipe blocked situation. As of May 31, 2006 , the 2nd boiler reheater wall pipe after 22961h and 24762h running test , the sealing structure fillet weld no cracking spill accident to 0.1 yuan / (kWh) of electricity generation efficiency calculations, due to wear caused by burst pipes forced outage one day loss of power caused by substitution are: 250,000 kWh × 0.1元(kWh) -1 × 24h = 60 Million / day Therefore, these measures effectively reduce the wear and tear squib the number of very substantial economic benefits strap seals .
Medium temperature, high temperature reheater wall pipe sealing structure optimization and transformation in reducing the number of burst pipes boiler repeatability and ensure safe operation of the boiler area , with significant economic and commercial integrated social benefits, while also having the same type of boiler better application value .
Installation of protective casing protective casing installation transition purposes : ( 1 ) casing material and its internal wall pipe of the same material , in order to ensure that the work of the tube with protective sleeve seam welded joints using the same kind of steel , will be transferred to the dissimilar steel welded joints with protective sleeve positioned between the seal plate welds , improved wall pipe work weld crack resistance ; ( 2 ) protection tube wall thickness thinner than the reheater tubes , which specifications for D68mm × 3mm, reducing its structural rigidity makes sealing welding deformation transferred to the casing ,indicative seals eliminating the formation of geometric stress concentration points , improved wall pipe work weld the force .
Construction should pay attention to the problems of access to the site reheater tube wall spectrum in addition to a 100% and 100% visual inspection , but also deal fillet weld pipe through the wall set at 100 % of the magnetic memory testing , to prevent unqualified ( exist melting wear , weld defects such as abnormal stress concentration ) pipe is used.
Note wall pipe positioning in the high roof pitch , the tube is in the process of looking for prohibited the use of flame cutting tools, in order to avoid the flame burn or cut high roof inside reheater tubes . Guaranteed replacement wall pipe before and after the reheater tubes mounted side elevation of the same, to prevent the tube rows down and obscure corner wall tube row spacing becomes smaller , resulting reheater appear swollen outer pipe blocked situation. As of May 31, 2006 , the 2nd boiler reheater wall pipe after 22961h and 24762h running test , the sealing structure fillet weld no cracking spill accident to 0.1 yuan / (kWh) of electricity generation efficiency calculations, due to wear caused by burst pipes forced outage one day loss of power caused by substitution are: 250,000 kWh × 0.1元(kWh) -1 × 24h = 60 Million / day Therefore, these measures effectively reduce the wear and tear squib the number of very substantial economic benefits strap seals .
Medium temperature, high temperature reheater wall pipe sealing structure optimization and transformation in reducing the number of burst pipes boiler repeatability and ensure safe operation of the boiler area , with significant economic and commercial integrated social benefits, while also having the same type of boiler better application value .
2013年10月9日星期三
Severe vibration pump inefficiency how to do
Workaround: polyimide carbon fiber composite materials for the pump casing mouth ring and bushing. Running clearance by the API standard down to 0.0015 inches per inch turning diameter .
Results: The initial vibration 0.600 inches / sec ,pull tite seals improved vibration 0.094 inches / sec , efficiency 5%.
Vibration : the vibration decreases the following reasons:
1 ) recirculation flow and its destabilizing effects of the rotor decreases ;
2 ) reduce the gap , the axis running decreases ;
3 ) There are natural and easy injection performance thermoplastic material to absorb shock or impact .
Efficiency : reduced efficiency because the pump casing and the gap between the impeller ring . Here the pump turn will reduce the internal recirculation gap .
Reliability : This pump has been more than four years of continuous work , the refinery has also been the polyimide carbon fiber composite materials for use in more than a dozen stage pump.
Polyimide carbon fiber composite material anti- abrasive material characteristics and advantages of the application :
a. has excellent wear resistance in abrasive particles in the working conditions better than rubber, bronze , carbon, graphite and other materials.
b. widely used in sewage pump , sea water pump ( the work environment is sand and other abrasive grains ) in the bushings, bearings and sized pipeline pump wear rings .
c. use is only recommended as a fixed component ( due to material temperature limits ) .
d. compared to other non-metallic materials,bolt seal anti- abrasive composite has better chemical resistance .
e. compared to the rubber bushing and other metallic materials , carbon fiber composite material of polyimide material has a very low coefficient of friction .
Results: The initial vibration 0.600 inches / sec ,pull tite seals improved vibration 0.094 inches / sec , efficiency 5%.
Vibration : the vibration decreases the following reasons:
1 ) recirculation flow and its destabilizing effects of the rotor decreases ;
2 ) reduce the gap , the axis running decreases ;
3 ) There are natural and easy injection performance thermoplastic material to absorb shock or impact .
Efficiency : reduced efficiency because the pump casing and the gap between the impeller ring . Here the pump turn will reduce the internal recirculation gap .
Reliability : This pump has been more than four years of continuous work , the refinery has also been the polyimide carbon fiber composite materials for use in more than a dozen stage pump.
Polyimide carbon fiber composite material anti- abrasive material characteristics and advantages of the application :
a. has excellent wear resistance in abrasive particles in the working conditions better than rubber, bronze , carbon, graphite and other materials.
b. widely used in sewage pump , sea water pump ( the work environment is sand and other abrasive grains ) in the bushings, bearings and sized pipeline pump wear rings .
c. use is only recommended as a fixed component ( due to material temperature limits ) .
d. compared to other non-metallic materials,bolt seal anti- abrasive composite has better chemical resistance .
e. compared to the rubber bushing and other metallic materials , carbon fiber composite material of polyimide material has a very low coefficient of friction .
Study abroad introduced for gear pump
Gear pumps for domestic and foreign research focuses on the following aspects:
( 1 ) Gear pump structure parameters and the optimal design of the basic design parameters of the gear pump determines the flow characteristics of the pump and the engaging performance index .truck seal Application optimization design method design parameters can be selected to meet the design requirements of gear parameters.
( 2 ) trapped oil shocks and unloading measure the phenomenon of trapped oil gear pump gear pump for the hydraulic system as a whole have had a lot of harm . Trapped oil shock and gear size and overlap factor unloading it completely and so have a great relationship ( including unloading slot position , shape and size , etc. ) .
( 3 ) the flow rate characteristics of the gear pump gear pump because a large flow pulsation , the pressure pulsation in some of the higher hydraulic systems , gear pumps rarely used . On reducing gear pump flow pulsation are already many ways , such as using composite gear pump ; reasonable choice of parameters gear ; using split gear.
( 4 ) new tooth profile of the gear pump technology research as computer-aided design and CNC machining technology rapid development , many of the past that is very complex surfaces in the design and manufacture of tooth profile becomes relatively easy. Thus, the emergence of various shapes tooth profile gear pump , such as linear conjugate tooth profile gear pumps , external gear type cycloid gear pump , and the outer envelope of the arc of the wedge toothed internal gear pumps. Straight tooth profile conjugate internal gear pump is considered to be the best overall performance ,stainless steel cable ties simple structure , displacement pressure , wide coverage, especially under high pressure , low noise and long life make it in the growing hydraulic technology figures prominently advantage position. Is Thus, for non- involute gear pump research is showing rapid development trend.
( 5 ) the characteristics of the composite compound gear pump gear pump gear pump can significantly reduce flow pulsation , but also has large displacement , small size , high mechanical efficiency , meshing force balance each other , etc. are taken seriously.
( 1 ) Gear pump structure parameters and the optimal design of the basic design parameters of the gear pump determines the flow characteristics of the pump and the engaging performance index .truck seal Application optimization design method design parameters can be selected to meet the design requirements of gear parameters.
( 2 ) trapped oil shocks and unloading measure the phenomenon of trapped oil gear pump gear pump for the hydraulic system as a whole have had a lot of harm . Trapped oil shock and gear size and overlap factor unloading it completely and so have a great relationship ( including unloading slot position , shape and size , etc. ) .
( 3 ) the flow rate characteristics of the gear pump gear pump because a large flow pulsation , the pressure pulsation in some of the higher hydraulic systems , gear pumps rarely used . On reducing gear pump flow pulsation are already many ways , such as using composite gear pump ; reasonable choice of parameters gear ; using split gear.
( 4 ) new tooth profile of the gear pump technology research as computer-aided design and CNC machining technology rapid development , many of the past that is very complex surfaces in the design and manufacture of tooth profile becomes relatively easy. Thus, the emergence of various shapes tooth profile gear pump , such as linear conjugate tooth profile gear pumps , external gear type cycloid gear pump , and the outer envelope of the arc of the wedge toothed internal gear pumps. Straight tooth profile conjugate internal gear pump is considered to be the best overall performance ,stainless steel cable ties simple structure , displacement pressure , wide coverage, especially under high pressure , low noise and long life make it in the growing hydraulic technology figures prominently advantage position. Is Thus, for non- involute gear pump research is showing rapid development trend.
( 5 ) the characteristics of the composite compound gear pump gear pump gear pump can significantly reduce flow pulsation , but also has large displacement , small size , high mechanical efficiency , meshing force balance each other , etc. are taken seriously.
2013年10月8日星期二
The use of diesel fuel pump maintenance considerations
1 , pump installation, to check the models, specifications are correct and clear anti-rust oil , the choice of gasket thickness should be appropriate to prevent excessive or too thick book the piston top dead or run in place , tighten the bolt tightening torque to evenly and prevent damage to the pump .
2 , pump the hand pump hand pump body between the piston and the rubber sealing device , do not arbitrarily dismantled, rubber Wai damage must be promptly replaced .
3 , within the coarse filter pump connector core vulnerable to dirt and clogged lint , etc. ,truck security seals should always check the cleaning, the filter damage must be promptly repaired or replaced .
4 , hand pump must be pushed back after use , the button tightened to prevent the hand pump and gasket or valve and the valve seat is not tight due to pressure caused by the intake or leaking.
5, to ensure plunger pump " four spring " flexible normal . "Four spring " for the piston spring , tappet ( wheel ) spring , inlet valve springs , delivery valve springs, elastic weakened or broken should be replaced or padded adjustments.
6, some pump casing has opened a vent hole , the hole is the role of a small amount of leakage pump diesel directly into the pump body. Holes shall not be blocked to prevent dilution of diesel into the fuel pump sump lubrication .
7 , to ensure that the entire gasket intact , plastic washers disassembly number should not be too much , and should be replaced periodically.
8 , found that diesel fuel injection pump sump too much , you should promptly check the pump piston and pump, tappet and tappet cover gap is too large, too large to be in time to prevent serious leakage due to diesel fuel , fuel pump and adjust the poor lubrication inside the mechanical speed .
9 , add diesel to be filtered through the sediment ,cable tie markers to ensure clean , and prevent excessive impurities exacerbated pump inlet valve , the oil valve seat wear , and sometimes even by impurities valve paving and failure.
10 , prolonged shutdown, preventing the pump mating surfaces , especially with the pump piston , tappet and tappet suite of water in the oil due to corrosion, rust measures must be taken ( downtime , replacement fuel pump sump inside with moisture , diesel oil and other impurities ) .
2 , pump the hand pump hand pump body between the piston and the rubber sealing device , do not arbitrarily dismantled, rubber Wai damage must be promptly replaced .
3 , within the coarse filter pump connector core vulnerable to dirt and clogged lint , etc. ,truck security seals should always check the cleaning, the filter damage must be promptly repaired or replaced .
4 , hand pump must be pushed back after use , the button tightened to prevent the hand pump and gasket or valve and the valve seat is not tight due to pressure caused by the intake or leaking.
5, to ensure plunger pump " four spring " flexible normal . "Four spring " for the piston spring , tappet ( wheel ) spring , inlet valve springs , delivery valve springs, elastic weakened or broken should be replaced or padded adjustments.
6, some pump casing has opened a vent hole , the hole is the role of a small amount of leakage pump diesel directly into the pump body. Holes shall not be blocked to prevent dilution of diesel into the fuel pump sump lubrication .
7 , to ensure that the entire gasket intact , plastic washers disassembly number should not be too much , and should be replaced periodically.
8 , found that diesel fuel injection pump sump too much , you should promptly check the pump piston and pump, tappet and tappet cover gap is too large, too large to be in time to prevent serious leakage due to diesel fuel , fuel pump and adjust the poor lubrication inside the mechanical speed .
9 , add diesel to be filtered through the sediment ,cable tie markers to ensure clean , and prevent excessive impurities exacerbated pump inlet valve , the oil valve seat wear , and sometimes even by impurities valve paving and failure.
10 , prolonged shutdown, preventing the pump mating surfaces , especially with the pump piston , tappet and tappet suite of water in the oil due to corrosion, rust measures must be taken ( downtime , replacement fuel pump sump inside with moisture , diesel oil and other impurities ) .
VRLA battery charge balance principle analysis
VRLA batteries ( hereinafter referred to as VRLA battery ) With saving investment , easy installation, safe, reliable, easy to use and other characteristics, in practical applications are heavily used. However, due to lack of understanding of its requirements and follows the old balance charging system, the battery causing great harm.
1 reason to cancel the equalizing charge
( A ) What is a balanced charge
The so-called balancing charge, the charge is balanced battery characteristics , is the process of using the battery , because the battery individual differences, temperature differences causes the battery terminal voltage imbalance , the imbalance in order to avoid deterioration of the trend , needs to improve battery set charging voltage , charging the battery activation .
( 2 ) the reasons for not equalizing charge
First, the concept of a balanced charge concept is used in the old-fashioned lead-acid batteries currently proposed large majority VRLA batteries are clearly stated, " voltage balance , into thoroughly ." The " battery acid layer is not formed , without the need for a balanced charge ." For single 2.4V battery charge voltage is defined as the charging speed , the "FASTCHARGE", rather than "EQUATION".
Secondly , a balanced valve-regulated battery charging will cause damage . Equalizing charge voltage for most batteries, are higher float voltage . At this point, most normal cells are in the overcharge status. The gas in the battery can not be combined within a certain pressure , the pressure control valve exceeds the safety threshold, the valve opens , the gas discharged from the control valve .
In previous battery maintenance , along with the process of equalizing charge the battery weight is adjusted such that the approach used to add distilled water add water , in order to maintain the equilibrium of the battery . However, the battery maintenance ,marker cable ties the maintenance of the existing system is water , and this way, water loss will inevitably cause the battery , dry battery .
2 Cancellation equalization charge, how to ensure the consistency of the battery terminal voltage
( 1) The battery terminal voltage determinant
Firstly, it is determined from the concentration of the electrolyte and the electrode materials . Cell dehydration , electrolyte concentration must increase , the battery terminal voltage increases. Secondly , the opening of the safety valve . If the pressure relief valve is too low, will inevitably lead to premature battery water loss , the terminal voltage rises. In addition , the series connection state between the battery is different, float occur when insufficient charging . When the battery is experiencing deep discharge recovery charge then , it is difficult to restore , this will cause the battery voltage is low.
( 2 ) the battery terminal voltage of assurance that
Since the battery terminal voltage will exist inconsistencies, do not allow battery equalizing charge , then the battery terminal voltage should be how to ensure consistency ? Should start battery raw materials, production processes to ensure the consistency of the battery voltage . The choice of materials such as batteries , in particular electrolyte plate , the pressure control valves and other key material selection .truck seal Second, we must ensure that the quality of the battery installed , ensure that the battery installed state consistency. For example, the battery connection method, such as the balance of torque . Also in the maintenance of attention. For some behind the recovery of batteries to be charged , but also properly adjusting the battery electrolyte ; should periodically check the pressure valve working condition.
1 reason to cancel the equalizing charge
( A ) What is a balanced charge
The so-called balancing charge, the charge is balanced battery characteristics , is the process of using the battery , because the battery individual differences, temperature differences causes the battery terminal voltage imbalance , the imbalance in order to avoid deterioration of the trend , needs to improve battery set charging voltage , charging the battery activation .
( 2 ) the reasons for not equalizing charge
First, the concept of a balanced charge concept is used in the old-fashioned lead-acid batteries currently proposed large majority VRLA batteries are clearly stated, " voltage balance , into thoroughly ." The " battery acid layer is not formed , without the need for a balanced charge ." For single 2.4V battery charge voltage is defined as the charging speed , the "FASTCHARGE", rather than "EQUATION".
Secondly , a balanced valve-regulated battery charging will cause damage . Equalizing charge voltage for most batteries, are higher float voltage . At this point, most normal cells are in the overcharge status. The gas in the battery can not be combined within a certain pressure , the pressure control valve exceeds the safety threshold, the valve opens , the gas discharged from the control valve .
In previous battery maintenance , along with the process of equalizing charge the battery weight is adjusted such that the approach used to add distilled water add water , in order to maintain the equilibrium of the battery . However, the battery maintenance ,marker cable ties the maintenance of the existing system is water , and this way, water loss will inevitably cause the battery , dry battery .
2 Cancellation equalization charge, how to ensure the consistency of the battery terminal voltage
( 1) The battery terminal voltage determinant
Firstly, it is determined from the concentration of the electrolyte and the electrode materials . Cell dehydration , electrolyte concentration must increase , the battery terminal voltage increases. Secondly , the opening of the safety valve . If the pressure relief valve is too low, will inevitably lead to premature battery water loss , the terminal voltage rises. In addition , the series connection state between the battery is different, float occur when insufficient charging . When the battery is experiencing deep discharge recovery charge then , it is difficult to restore , this will cause the battery voltage is low.
( 2 ) the battery terminal voltage of assurance that
Since the battery terminal voltage will exist inconsistencies, do not allow battery equalizing charge , then the battery terminal voltage should be how to ensure consistency ? Should start battery raw materials, production processes to ensure the consistency of the battery voltage . The choice of materials such as batteries , in particular electrolyte plate , the pressure control valves and other key material selection .truck seal Second, we must ensure that the quality of the battery installed , ensure that the battery installed state consistency. For example, the battery connection method, such as the balance of torque . Also in the maintenance of attention. For some behind the recovery of batteries to be charged , but also properly adjusting the battery electrolyte ; should periodically check the pressure valve working condition.
2013年10月7日星期一
Pump mechanical seal dimensional inspection should pay attention to several issues
1 , lubrication
The mechanical seal faces should be properly lubricated , thus reducing wear and prolonging life , some lubricant friction heat can also be taken away . Lubricants generally assumed by the media itself , thus sealing face ( ring, stationary ring ) see spring pressure should not be too large.
2 , flush cooling
Pump mechanical seal end face of the work so that the heat generated should be promptly passed out, otherwise it will vaporize liquid film between the end faces formed by dry friction, flush cooling measures must be considered .
Generally flush with internal coolant security seals sealing medium , may also have an external water supply cooling water. Should be used in mechanical seal flushing coolant absolute guarantee of supply and flush the coolant flow, if necessary cleaned regularly.
3, the old seal update
In contrast with the new mechanical seal better than the old , but the new mechanical seal quality or choice of material is not the time , with the larger size of the error will affect the sealing effect ; sexual penetration in the polymerization medium, the stationary ring without excessive wear, or not to replace as well. Because static ring stationary ring seat for a long time in a quiescent state , the polymer and impurities deposited as a whole, played a good seal.
4 , the seal overhaul
Once the mechanical seal leakage will be eager to overhaul , in fact , sometimes sealed and not damaged , tamper seal tape simply adjust the working conditions or the seals can be adjusted to eliminate leakage. This way to avoid waste and to verify their ability to judge the fault has accumulated experience in maintenance to improve the quality of maintenance .
The mechanical seal faces should be properly lubricated , thus reducing wear and prolonging life , some lubricant friction heat can also be taken away . Lubricants generally assumed by the media itself , thus sealing face ( ring, stationary ring ) see spring pressure should not be too large.
2 , flush cooling
Pump mechanical seal end face of the work so that the heat generated should be promptly passed out, otherwise it will vaporize liquid film between the end faces formed by dry friction, flush cooling measures must be considered .
Generally flush with internal coolant security seals sealing medium , may also have an external water supply cooling water. Should be used in mechanical seal flushing coolant absolute guarantee of supply and flush the coolant flow, if necessary cleaned regularly.
3, the old seal update
In contrast with the new mechanical seal better than the old , but the new mechanical seal quality or choice of material is not the time , with the larger size of the error will affect the sealing effect ; sexual penetration in the polymerization medium, the stationary ring without excessive wear, or not to replace as well. Because static ring stationary ring seat for a long time in a quiescent state , the polymer and impurities deposited as a whole, played a good seal.
4 , the seal overhaul
Once the mechanical seal leakage will be eager to overhaul , in fact , sometimes sealed and not damaged , tamper seal tape simply adjust the working conditions or the seals can be adjusted to eliminate leakage. This way to avoid waste and to verify their ability to judge the fault has accumulated experience in maintenance to improve the quality of maintenance .
Sealant Product Features
1 -component, moisture curing , facade construction is not flowing ;
2 flexible, good tack , moderate intensity ;
3 with glass,tamper evident tape aluminum and other materials, good adhesion ;
4 good sealing performance ;
5 interrupt when drawing gluing short ;
7 low volatile odor ;
8 excellent anti-aging properties:
Sealants used in packaging advantages:
Sealing a direct impact on packaging effect , packing and storage life , and even affect the credibility of the packaging . To this end , the sealing glue has become an important part of the packaging . Sealing material in accordance with the form and use can be broadly divided into gasket , sealing tape sealing and colloid and other categories , can reach to prevent liquid leakage , blocking oxygen, moisture , odor -proof forgery, counterfeit products are intended . Security seal , numbered seals sealed packaging in recent years the rise of technology, generally hot melt pressure sensitive adhesive tape or sticky point sealed envelope , packaging can not be dismantled once the restitution, thereby preventing counterfeit products appear to protect the interests of consumers.
2 flexible, good tack , moderate intensity ;
3 with glass,tamper evident tape aluminum and other materials, good adhesion ;
4 good sealing performance ;
5 interrupt when drawing gluing short ;
7 low volatile odor ;
8 excellent anti-aging properties:
Sealants used in packaging advantages:
Sealing a direct impact on packaging effect , packing and storage life , and even affect the credibility of the packaging . To this end , the sealing glue has become an important part of the packaging . Sealing material in accordance with the form and use can be broadly divided into gasket , sealing tape sealing and colloid and other categories , can reach to prevent liquid leakage , blocking oxygen, moisture , odor -proof forgery, counterfeit products are intended . Security seal , numbered seals sealed packaging in recent years the rise of technology, generally hot melt pressure sensitive adhesive tape or sticky point sealed envelope , packaging can not be dismantled once the restitution, thereby preventing counterfeit products appear to protect the interests of consumers.
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