Valves are the most common type of processing equipment. Valves are used for many purposes:
- Isolation
- Throttling
- Safety Release (discussed in a previous segment)
- Sampling
- Flush Bottom
Within each basic type of valve, the options and choices can be staggering: Type, Size, Rating, Body Material, Seat Material, Full Flow, Manual vs Actuated, etc. The possibilities are almost endless. Almost every one of the parameters just mentioned will be critical selections when you specify a valve. The right (or wrong!) combination can be the difference between process success and a maintenance nightmare.
Aside from proper valve selection, careful consideration should be given to how the valves will interact with and mount to your pressure equipment. Isolation valves can take a number of forms, such as gate valves, ball valves, or plug valves. Additionally, if a process consideration is complete drainage of a pressure vessel, it may make sense to utilize a flush bottom valve, which allows more complete draining than a standard valve. The flush bottom valve casting is actually welded to the pressure vessel and becomes integrated, so that option must be known at the time of pressure vessel design in order to incorporate it. Likewise, if a ram-type sampling valve is important to the process, then special pad flanges must be designed along with the pressure vessel to ensure proper fitment and functionality.
These are just a few of the details that must be examined when it’s time to select proper valves for your processes. The associated pressure equipment must often be designed around the valves being used in and around them.
