Features and Benefits 

Cast Iron Gate Valve, also called Water Gate Valve.It is specially designed to suit for transportation,distribution and extraction system in water, air, oil and gas industry.Their bodies are made from ductile iron or cast iron and have integral flanges which are available in two basic types: non-rising stem (NRS) Inside Screw and rising stem Outside Screw and Yoke type. The inside screw type has the stem actuating thread within the pressure envelope and is non-rising. This type of valve is usually used for non corrosive and reasonably clean services and has a smaller overall height than the outside screw type. The outside screw, rising stem type has the stem actuating thread outside the pressure envelope and can be used on more active media where the fluid might otherwise have an adverse affect on the thread.

Design 

Resilient seat and Metal Seat are 2 type of seats for Cast Iron gate valve. Before the resilient seated gate valve was introduced to the market, gate valves with a metal seated wedge were widely used. The conical wedge design and angular sealing devices of a metal seated wedge require a depression in the valve bottom to ensure a tight closure. Herewith, sand and pebbles are embedded in the bore. The pipe system will never be completely free from impurities regardless of how thoroughly the pipe is flushed upon installation or repair. Thus any metal wedge will eventually lose its ability to be drop-tight. 

A resilient seated gate valve has a plain valve bottom allowing free passage for sand and pebbles in the valve. If impurities pass as the valve closes, the rubber surface will close around the impurities while the valve is closed. A high-quality rubber compound is soft enough to absorb impurities, yet strong enough to wash the impurities through when the valve is opened again. This means that the rubber surface will regain its original shape securing a drop-tight sealing. 

Shield ^TM  Gate Valves are used when the need exists for a device that allows an interruption or cut off in the flow or fluid. Gate Valves arenot to be used for flow modulations as the high velocity through a partially open valve may result in erosive damage to the wedge andseats. Under normal operating conditions, the valve should remain either fully open or fully closed. Installation of a Gate Valve does not depend on the flow direction.