Model 81 Multi-Stage Pressure Regulator from Rotork Fairchild

Model 81 Multi-Stage Pressure Regulator from Rotork FairchildRotork Fairchild Model 81 is a high flow two stage precision pressure regulator designed for applications that require high performance, low droop and accurate process control. The Model 81 combines a pilot control system with a basic force balance system to provide accurate output pressure regulation for both highly sensitive instrumentation and control circuits and in equipment requiring high flow with precise control.

Operating Principles
This Model 81 is a precision two-stage regulator that combines a pilot control system with a basic force balance system to provide accurate output pressure regulation. 

It is recommended for use in both highly sensitive instrumentation and control circuits and in equipment requiring high flow with precise control.

Features

Model 81 Multi-Stage Pressure Regulator Features

  • Five output pressure ranges from 0-20 psi, 0-1.5 BAR, 0-150 kPa up to 1-100 psi, 0.05-7 BAR, 7-700 kPa
  • Flow capacity of 50 SCFM, 136 m3/hr
  • Sensitivity of less than 0.1" water column - well suited for high accuracy applications
  • Force balance and 2 stage pilot control minimizes any droop from downstream flow
  • High flow capacity - responsive operation with less exhaust time
  • Sapphire orifice provides precise control of pilot control air flow
  • Low air consumption - efficient operation with no losses of air or gas media
  • Available in 1/4" NPT port size

Specifications

Model 81 Multi-Stage Pressure Regulator Specifications

SpecificationDetails
Flow Capacity (Nominal)50 SCFM (85 m³/hr) @ 100 psig [7.0 BAR, 700 kPa] supply; 20 psig [1.5 BAR, 150 kPa] setpoint
Exhaust Capacity5.5 SCFM (9.4 m³/hr) with downstream pressure 5 psig [0.35 BAR, 35 kPa] above setpoint
Maximum Supply Pressure2, 5 psig [0.15, 0.35 BAR, 14, 35 kPa] ranges: 100 psig [7.0 BAR, 700 kPa] 20, 60, 100 psig [1.5, 4.0, 7.0 BAR, 140, 400, 700 kPa] ranges: 150 psig [10 BAR, 1000 kPa]
Minimum Supply Pressure20 psig [1.5 BAR, 150 kPa]
Maximum Output Pressure100 psig [7.0 BAR, 150 kPa]
Pressure Change (due to supply variation)< 0.2 psig [0.013 BAR, 150 kPa] for 100 psig [7.0 BAR, 700 kPa] change in supply pressure
Air Consumption< 0.1 SCFM [1.7 m³/hr]
Sensitivity< 0.1″ [0.254 cm] Water Column
Ambient Temperature Limit-40°F to +200°F (-40°C to 93°C)
Materials of Construction
  • Body: Die Cast Aluminum
  • Trim: Stainless Steel, Brass, Aluminum, Plated Steel
  • Diaphragms: Nitrile on Dacron
  • Orifice: Sapphire

 

Q & A

Model 81 Multi-Stage Pressure Regulator Q & A

+ What is the nominal flow capacity of the Model 81?
The regulator has a nominal flow capacity of 50 SCFM (85 m³/hr) at 100 psig [7.0 BAR, 700 kPa] supply with a 20 psig [1.5 BAR, 150 kPa] setpoint.
+What is the exhaust capacity of the Model 81?
The exhaust capacity is 5.5 SCFM (9.4 m³/hr) when downstream pressure is 5 psig [0.35 BAR, 35 kPa] above the setpoint.
+What is the maximum supply pressure?
The Model 81 supports maximum supply pressures up to 150 psig [10 BAR, 1000 kPa], depending on the output range selected. Specific ranges include 2–5 psig [0.15–0.35 BAR, 14–35 kPa], 20–100 psig [1.5–7 BAR, 140–700 kPa].
+What is the minimum supply pressure?
Minimum supply pressure is 20 psig [1.5 BAR, 150 kPa].
+ What is the maximum output pressure for the Model 81?
The maximum output pressure is 100 psig [7.0 BAR, 150 kPa].

Downloads

Download Rotork Fairchild Model 81 Multi-Stage Pressure Regulator Datasheet

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