进口平板闸阀

The HANOVER gate valves are of through conduit design.When the valve is completely open,the port of the valve becomes a fully cylindrecal bore allowing for the passage of pigs and scrapers. The full open bore of the port reduces flow turbulence and pressure drop through the valve equal to a length of pipe the same size.

This function provides a means to bleed pressure in the body cavity to zero with the valve closed when there is upsream or downstream pressure on the valve.

The stem packing is Chevron V-Packing vhich is energized by the injection of bulk plastic packing. In the event of an emergency stem packing leak, additional plastic packing can be injected to stop the leak

The PGS type fate valve has a floating seat design. A positive upstream seal is formed when the seat is pushed against the gate by the sealing force of the ODO-ring. Six inch valves and larger have an injection fitting to supply sealant to sthe surface of the seat to stop an emergency leak. If for some reason the line pressure in the body cavity rises abnormally above the line pressure,the floating sea is retracted into the seat pocket by the pressure difference to automatically relieve pressure to the line.

The PGS type gate valve is designed to close fully in both the upstream and downstream positions. Unless otherwise specified, a relife valve (accessory) is installed on the valve body to prevent abnormal internal body pressure.

Six inch valves and larger are provided with an injection fitting to supply sealant to the surface of the seat to stop an emergency lead.

The body is provided with a fiffing to relieve pressure in the body cavity and drain the fluid or foreign substances. This fitting can also serve as a grease fitting to fill the body cavity.

Any type of actuator may be installed on the valve. (Gear actuator,electric actuator, pneumatic actuator, or electric-hydraulic actuator)

Stem extensions of any length are available for under-ground valves with extended drain and sealant connections if required.

The expanded gate gives a positive seal when the valve is fully opened or closed.When the valves is in the full open or closed position,the gate assembly mechanically actuated against the upstream and downstream seats to provide positive sealing.When the gate moves between the open and closed positions,it becomes smaller in thickness resulting in reduced friction for smoother operation.

The seat ring has a PTFE seat seal insert. When the valve is closed, a positive double seal is formed by the contact of PTFE-to metal (primary seal) and metal-to-metal (secondary seal) on the upstream and downstream seats.Sixinch valve and larger have a sealant injection fitting for use to seal an emergency seat leak.