The Sentry Back Pressure Regulator/Relief Valve (BPRV) maintains constant pressure and constant analyzer flow while protecting critical sampling components as a relief valve. The Sentry BPRV relief valve holds a constant pressure of approximately 20 psig (1.4 barg) at the analyzer inlet when installed as recommended. This pressure is maintained independent of source pressure fluctuations or sample flow changes. If inlet pressure rises, the regulator opens to let excess flow pass through to drain. This flow is usually used as the grab sample. This unit also acts as a relief valve in the event of an over-pressure condition.
When severe service pressure reduction is handled by a Sentry VREL valve or needle valve, the BPRV only has to control pressure between 20 psig (1.4 barg) and atmosphere. This allows precise pressure control, minimizes plugging and ensures high reliability.
Benefits
Precise pressure reduction and control when used in conjunction with a VREL or needle valve
Most effective way to assure a constant flow rate to on-line analyzers
Specially designed for steam/water sampling service
Non-plugging design
Will not wire draw or erode in normal service
Fail safe relief valve