Marsh Bellofram PCD Division Type 77 Vacuum Regulator Series - Marsh Bellofram - #1

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28 800.727.5646 • www.marshbellofram.com Air Regulators TYPE 77 Sensitivity 1/2" (1.3 cm) Water Column Flow Capacity 2.5 SCFM (71 L/M) @ 29" Hg (740 mm Hg) Vacuum 40 SCFM (1130 L/M) @ 100 PSIG (6.9 BAR) supply, 20 PSIG (1.4 BAR) output Effect of Supply Pressure variation (25 psig/1.7 BAR) on Outlet Pressure Less than 0.1 PSIG (0.01 BAR) Exhaust Capacity@ 5 psig (0.34 BAR) above setpoint 4 SCFM (113 LPM) Maximum Supply Pressure 250 PSIG (17.2 BAR) Ambient Temperature Limits -40 to 200¢ªF (-40 to 93¢ªC) Output Pressure Ranges Vacuum to 2 PSIG (0.1 BAR) Vacuum to 10 PSIG (0.7 BAR) Vacuum to 30 PSIG (2.1 BAR) Vacuum to 100 PSIG (6.9 BAR) Vacuum to 150 PSIG (10.3 BAR) Total Air Consumption @ Maximum Output 6 SCFH (2.8 LPM) Port Size 1/4 NPT, 3/8 NPT, 1/4 BSPT, 3/8 BSPT Materials of Construction Body: Diecast Aluminum with Vinyl Paint Trim: Stainless steel, Brass, Plated steel, Acetal and Buna-N Diaphragm: Buna-N with Polyester Fabric Knob: Phenolic Plastic Spring: Music wire Mounting Options Pipe, Panel or Bracket Features • Single-unit control of pressures from 29" Hg vacuum to 150 PSI • Flow capacity up to 40 SCFM • Dampening action of aspirator tube maintains stable output pressure • Output virtually unaffected by changes in supply pressure • Can be disassembled and serviced without removing from line Type 77 Vacuum Regulator Series Type 77 Vacuum Regulator Series Description Bellofram’s Type 77 Vacuum Regulator incorporates a fixed negative 15 PSIG bias spring to maintain vacuum outputs up to 29" Hg. An adjustable opposing range spring increases controlled pressure outputs up to 150 PSIG. Output pressure droop under varying downstream flow conditions is minimized by use of an aspirator tube which adjusts the air supply valve opening in accordance with flow velocity. A balanced supply valve, utilizing a reinforced rolling diaphragm, keeps regulator output virtually immune to changes in supply pressure. Stack-up construction makes the Type 77 easily serviceable, without removing it from the air line. Applications The Type 77 provides precise control in subatmospheric pressure applications. Specific uses include sample collecting systems, air quality monitoring, parts coating operations, and other industrial functions requiring controlled system pressure from 29" Hg vacuum to 150 PSIG. The regulator may be installed either upstream or downstream from the vacuum pump. Upstream installation (Figure 1) is preferred when rapid evacuation of a vessel or system is required, because the exhaust capacity of the pump is normally greater than that of the regulator. In all other applications, the regulator can be located between the pump and the vessel. (Figure 2)