Seal to enhance plug valves

metal seal plug valve poppet valve seat sealing surface can be sealed on both sides of the valve without the use of media flow restrictions. Metal seal body to enhance type plug is closed, and the valve stem through the hand wheel on the valve seat sealing surface pressure, by increasing the sealing pressure than that enable plug has better sealing performance. Seat sealing surface projection, easy clean sealing surface, the sealing surface is not easy to accumulate crystallization medium, or solid particles. Solid commonly used in the chemical plant high temperature applications. Seal to enhance the structure of a variety of plug valves, there are two common.
A. The handwheel lever hoist plug valves, the working principle is: the rise, the taps and valves fully open. First turn off when the handle is rotated by 90 degrees to the cock closed position, and then turn the hand wheel gear down to seal the cock.
Cock valve opening and closing process again separated from the valve seat, the valve opening and closing is very easy, and the sealing surface in the open or close the process is not easy bruising, valve long service life. But the use of the handle drive torque is small, so use the valve nominal size is usually small. Handwheel handle to enhance type plug compact structure, small size, fluid resistance.
B. Mechanical cross transmission to enhance type plug, works as follows: Open the valve gear rotating the valve stem threads to make cock-ups. Taps and valve sealing surface and then driven out of turn 90 degrees to the cock valve fully open. Drive off when the cock is rotated by 90 degrees to the first closed position, the plug is no longer rotated, the driving force of turning the threaded down after the cock, in contact with the valve sealing surface to security seal.
Mechanical transmission mechanism can be connected to the cross cylinder, electric devices, hydraulic systems and other remote control.
Mechanical cross transmission to enhance type plug, solves insufficient drive input torque limit, the valve to the large diameter and high pressure direction.
Mechanical transmission to enhance cross-channel type plug cocks consistent with the diameter of the pipe, the fluid resistance is small, easy to pigging. In the oil and gas development on the long pipeline is growing.