Type 78 Direct-Acting Air Pressure Regulator

Brand: Marsh Bellofram Group of Companies

The Type 78 Direct Acting Air Pressure Regulator designed from Bellofram PCD is design to offer high-accuracy, large flow and exhaust capabilities within OEM and industrial applications.

Available in five different pressure output ranges to 125 psig (8.6 BAR), this precision regulator offers low droop, high accuracy and fine adjustment sensitivity with maximum supply pressure rated at 400 psig (27.6 BAR) and achievable flow rates of well over 200 SCFM.

The unique design of the Type 78 features a patented Bellofram rolling diaphragm, offering greater sensitivity and improved accuracy, along with low-friction operation and long useful service life.

The Type 78 also offers low droop, fine adjustment sensitivity and a balanced pintle, which minimizes output pressure changes caused by supply pressure fluctuations. Careful design and use of quality manufacturing materials ensures long, trouble-free operation, along with a chemical conversion coating of all cast components and a vinyl paint finish.

Additional optional features and accessories include low-bleed, non-relieving, square head adjustment, T-handle adjustment, tamper resistant cover, epoxy paint, tapped supply gauge port and tapped exhaust. Mounting brackets and repair kits are also available.
  • Rugged die-cast zinc and aluminum housings, pressure treated for use in harsh environments. 
  • Port sizes of 3/8", 1/2", 3/4" and 1" NPT and BPST with 1/4" NPT gauges. 
  • Five different pressure output ranges of up to 125 psig (8.6 BAR). 
  • Maximum supply pressure rated at 400 psig (27.6 BAR). 
  • Achievable flow rates of well over 200 SCFM. 
  • Pipe or rail mounting capabilities.


Port Size

  • 3/8” NPT, 1/2” NPT, 3/4” NPT, 1” NPT
  • 3/8” BSPT, 1/2” BSPT, 3/4” BSPT, 1” BSPT

Enclosure / Body Material

  • Die-Cast Zinc
  • Aluminum

Supply Pressure - Maximum

  • 400 psig (27.6 bar)

Material of Construction

  • Bonnet: Die Cast Aluminum Alloy
  • Knob: Phenolic Plastic, Plated Steel
  • Internals: Brass, Stainless Steel, Zinc

Diaphgram Material

  • Nitrile Elastomers


  • Less than 1” WC column

  • High-flow Actuation
  • High-flow Louvers
  • Rollers and Winders
  • High-flow Control Loops
  • Calibration Loops
  • Any OEM or Industrial Pressure Regulator Application Where High-accuracy is Required


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