Bellofram Precision Controls
Pneumatic (Air) Relays
Marsh Bellofram pneumatic relays are designed to provide cost-effective, high-performance air regulation across a variety of applications, and in support of a variety of market requirements. Available versions and types include two-stage, pilot operating 1:1; positive and negative biasing, positive bias booster, high relief, adjustable bias, and ratio high-flow relays, all of which provide highly accurate and reliable output pressure control.
Type 20 Precision Pneumatic (Air) Relay
The Marsh Bellofram Type 20 is a compact, two-stage, pilot operated 1:1 air relay with positive and negative bias adjustment capability. It accepts a signal pressure and, when combined with bias adjustment, maintains a resultant output pressure with an accuracy and reliability unmatched by any other industry air pressure relays in its price range.
Type 72 & 72HR Positive Bias Booster
Marsh Bellofram Type 72 positive bias booster pneumatic relays are used when high flow capacity is required. Offered in four adjustable ranges with optional high-relief version, units feature an adjustable bias pressure which enables users to obtain positive output as the sum of a controlled input signal pressure plus bias. The 72HR is a high relieving version.
Type 75 & Type 75HR Pneumatic (Air) Relays
Marsh Bellofram Type 75 pneumatic (air) relays use signal pressure technology to accurately control output pressure over a wide range of flow and supply pressure variations. Under these varying flow conditions, output pressure is maintained by use of an aspirator tube, which adjusts the air supply valve opening in accordance with flow velocity. A high relieving version, the Type 75HR, is also available.
Type 79 & Type 79HR 1:1 Ratio High-Flow
Marsh Bellofram Type 79 1:1 ratio high-flow precision pneumatic (air) relays are designed for applications where precise flow control is required and particularly, for use in harsh environments. Use of a balanced pintle accurately controls output pressure over wide flow and supply pressure variations, while minimizing output changes caused by supply fluctuations. A high relieving version, the Type 79HR, is also available, offering 25% additional exhaust capability..
