Gate Valve Selection Guide
There are two basic types of gate valves that can be purchased and installed as part of the plumbing system of a structure. These two types depend on the manner in which the disk is designed in the actual gate valve. As mentioned in the article parts of a gate valve, the gate valve disk is basically the gate that can seal shut when the valve is closed, meaning no water flow is possible, and can open when the valve is opened, allowing water pressure to pass through.
The two basic types of gate valves are:
1. Parallel Gate Valve
The parallel gate valve is used in valves that have parallel valve seats. The two halves of the parallel disk can either be thrust together or spread apart and there is often a spring-like mechanism that assists in the proper sealing of the disks to the seats. There is a variety of designs that use the parallel gate valve but the bottom line for each design is to make sure that there is optimum sealing that occurs between the disks and the seats.
2. Wedge Gate Valve
The wedge gate valve is separated into three categories:
- Solid Wedge: The solid wedge gate valve is considered to be the most commonly used disk and is known for the simplicity in its design that belies its strength. The solid wedge gate valve functions well in any position it is placed in and can handle almost any kind of fluid.
- Flexible Wedge: The flexible wedge gate valve is a singular disk whose perimeter has a cut around it in order to be able to fit better in the valve seats. The cut depends on the design of the valve seats and the flexible wedge gate valve works best with steam systems since heat can cause expansion and cold can cause contraction, making it necessary for more flexibility to occur within the disk.
- Split Wedge: The split wedge gate valve has a ball and socket design that are able to self-adjust and self-align to the valve seats’ surfaces. This makes it possible for half the disk to adjust and align itself if the other half is unable to do so due to something being lodged that makes it impossible for it fit snugly into the valve seat. The split wedge gate valve is appropriate for systems that handle non-condensing gases and liquids.
Knowing the right kind of gate valve to select depends greatly on how you are planning to use it in your piping system.One particular type of design may work specifically for plumbing purposes in a home while another type of design may work better in an industrial setting. This is why it is important to have the correct information on each type of gate valve and whether they will meet your specific requirements and needs. A professional's advice and guidance can help whittle down the choices and recommend which one will work best in your precise setup.