The cost of valves in a piping system generally makes up 20 to 30% of the overall piping cost, yet the cost of valves varies significantly, depending on the type and size of valve. To cost your project economically, you will need to choose the valves for your piping system with care.
A valve is a mechanical device that regulates, controls or directs the flow of a fluid by opening, closing, or partially obstructing fluid flow. In essence, it controls the flow and pressure of fluid within a system or process. If you choose a ball valve over a butterfly valve, for instance, both valves may be able to do the job, but it would cost you more.
Some of the more popular valves that are available are:
Gate valves
These are commonly used by process plants for fluid services, such as air, fuel gas, feedwater, steam, lube oil and hydrocarbon. As linear motion valves, they start or stop fluid flow and are either in fully open or fully closed position.
Globe valves
Globe valves start, stop and regulate fluid flow. They are ideal for systems where flow control and leak tightness is required. Globe valves shut off better than gate valves.
Check valves
These valves prevent backflow in a piping system. Fluid pressure opens these valves, while reversal of flow closes them.
Plug valves
Plug valves use a tapered or cylindrical plug to stop or start flow in vacuum to high-pressure and temperature applications. The disk is in a plug shape, which has a passage to pass the flow.
Ball valves
Like plug valves, ball valves are quarter-turn rotary motion valves, but ball valves stop or start flow with a ball-shaped disk. Most ball valves are quick-acting, so the handle requires a 90° turn to operate the valve. These are smaller and lighter than the same size and rating gate valves.
Butterfly valves
These are also quarter-turn rotary motion valves, used to stop, regulate and start flow. With a short, circular body and compact, lightweight design, butterfly valves can be used in large valve applications where there is little space for valves.
Needle valves
Needle valves can accurately control flow in small diameter piping systems. While similar in design to globe valves, the biggest design difference is the sharp needle like a disk.
Pinch valves
Pinch valves, also known as clamp valves, are linear motion valves that start, regulate and stop fluid flow. A rubber tube, known as a pinch tube, and a pinch mechanism control fluid. Pinch valves can be used in the handling of slurries, liquids with suspended solids and systems that convey solid material pneumatically.
Pressure relief valves
Pressure relief valves, also known as pressure safety valves, can protect equipment or piping systems during an overpressure event or in the event of a vacuum. They release pressure or the vacuum at set pressure points.
Not sure which valves would suit your system? Please speak to us. We also offer consulting services.