Process measurement and control employs a wide array of gauges and instruments that may be permanently or temporarily connected to a piping system. Providing controlled isolation and connection of these instruments is the function of what are generically referred to as “instrument valves” or “gauge valves”. These valves are generally small, with connection sizes ranging from 1/8″ to 1″, though there are specialty variants outside this range. The predominant valve type is a needle valve, but ball valves and some other types are also used. Certain attributes of particular applications may weight a selection decision toward a valve type. Widely used throughout the process industries, instrument valves are often designed to accommodate pressures as high as 6000 PSI and are intended for service with gaseous or liquid service.
When selecting an instrument valve, consider construction materials that are compatible with the process media. Additionally, operating temperature and pressure of the process must be well within the limits of the valve.
