Stainless steel pressure regulators are used where operation and installation situation require high-grade materials. These requirements are different and depend on the application: corrosion-proof against acids and lye, different solvents and liquids, also for the use in demineralized water.
Further requirements are uniform properties of control quality and flow at lowest wear in the seat and with high dynamics at the same time. Especially in very long pipes, high changes in pressure (pressure drop) can be expected. Pressure regulators with pressure compensated trim design can keep the outlet pressure and so the flow will be constant and independent of the inlet pressure fluctuations.
The recent past, more and more regulators with remote control of dome pressure are used besides regulators with a manually adjustable spring.