There are three main types of valves available in the market. Therefore, it’s important to pick the right valves for your application, especially underground. Purchasing the wrong valve can lead to high replacement costs and time wastage. Getting the right one depends on what you need in terms of temperature and pressure ratings. Below are the types and their applications.
Varieties of gate valves
Gate valves for water supply come in the following categories :
- By wedge: parallel and wedge gate valves• By seat: resilient or metal seat gate valves• By stem: With rising or non-rising stem• Parallel or wedge-shaped gate valves
- Parallel and wedge gate valves
These gate valves are flat, parallel-faced gate-like closing elements fitting between two parallel seats. They acquired the name because they have a wedge-shaped gate.
Use
- To transmit the axial loads inflicted on the wedge by the medium to the valve body• To promote the low-friction motion of the wedge in a radial direction• To stop the wedge from rotation while traveling between open/closed valve positions (serving as an anti-twist lock).
- Metal seated or resilient seated gate valves.
Wedge gate valves can have metallic or resilient seats. But in metal seated gate valves, a wedge grinds towards a groove in the invert of the gate valve body. As a result, it sometimes traps solids retained in the fluid. Due to this, these valves offer a tighter shut-off and are mostly used in water redistribution systems.
Resilient gate valve manufacturers make a wedge out of ductile iron in elastomer, which provides a tighter seal. The sealing occurs between the wedge rim and valve body, and there is no need for a groove at the valve base. Instead, the gate valve manufacturers design them to seal around tiny solids in the water flow. Note there are a variety of connection options for every application. - Rising stem or non-rising stem gate valves
The distinction between the two is they can either be fixed or interwoven into the gate. The revolving stem rises in the rising gate valves once the valve opens.
Cons of rising stem valves
- They come in a bulky design, so they need a lot of room when the spindle moves upwards.• It is not recommended for below ground installations.
There you have it: all the gate valves and their applications. Therefore, next time you pick a gate valve, choose one that suits your needs.
