Regulators

Pressure regulators hold a pressure constant without any external power or control signal: the process fluid itself, acting on a diaphragm against a spring, positions the valve. Seven Star LLC supplies pressure reducing regulators, back pressure regulators, filter regulators and volume boosters in Oman from Masoneilan, Fisher, SMC and Swagelok.

Most of the 31 listed items are Masoneilan regulators and pneumatic relays. A Hale Hamilton hydraulic regulator is also included.

Pressure reducing, back pressure and instrument air regulators

A pressure reducing regulator senses downstream pressure and closes as it rises. Listed examples are the Masoneilan 171 and 174 Series direct-operated regulators, the 525 double-seated and 535H single-seat regulators, the Fisher 627 and the Swagelok KPR Series. A back pressure regulator, such as the Masoneilan 536H or the 536V for very small flows, senses upstream pressure and opens as it rises, so it holds pressure on a vessel, a pump recirculation line or a sample system. Filter regulators such as the SMC AW40 clean and reduce compressed air for pneumatic equipment. Volume boosters, here the Masoneilan BR200 and BR400, are relays that repeat a pneumatic signal at a much higher air flow to stroke large actuators more quickly.

How to select a pressure regulator

Define the inlet pressure range, the outlet set pressure and the flow range, then check the fluid and temperature against body, trim and diaphragm materials. Direct-operated regulators are simple and respond quickly, but outlet pressure falls somewhat as flow increases, an effect called droop. Pilot-operated regulators hold pressure more closely over a broad span of flow and suit larger capacities. Choose the spring range so the set point sits near its middle. Remember that a regulator is a control device and does not replace a safety relief valve downstream. For sour gas, wetted materials must comply with NACE MR0175 / ISO 15156.

Data for a gas, air or liquid regulator quotation

Send the fluid, minimum and maximum inlet pressure, required outlet or back pressure, minimum and maximum flow, temperature, line size and end connections, and the body material. For a replacement, the model number and spring range from the nameplate are usually sufficient. We check the configuration against the manufacturer documentation for buyers across the GCC.