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Marsh Bellofram has designed its 72 Series positive bias booster pneumatic relays for use within industrial air pressure regulation and monitoring applications in which high-flow capacity is required. The company says that this series additionally features:
- A Bellofram-patented internal rolling diaphragm, making the relay virtually immune to changes in supply pressure, while offering reliable performance over millions of cycles.
- The accurate maintenance of output pressure under varying flow conditions by means of an aspirator tube, which adjusts the air supply valve opening in proportion to flow velocity.
- 4 adjustable positive bias ranges — from 0 to 10 PSI (0 to 0.7 BAR) and from to 2 to 150 PSI (0.1 to 10.3 BAR).
- A high-flow capacity up to 50 SCFM (1,400 LPM) with minimal pressure drop.
- A quick response to minute changes in downstream pressure.
- The flexibility to disassemble and service the relay without removing it from the line.
- A standard 1:1 signal-to-output ratio, but availability of 1:2, 1:4 and 1:6 ratios on special request.
- A simple, maintenance-free design.
- An optional Type 72HR high-relief version of the relay.