Model 14 Positive & Negative Bias Relay

Brand: Fairchild Industrial Products - by Rotork

Designed for applications that require an output pressure that is the sum of a controlled input signal plus or minus a fixed bias, Rotork Fairchild's Model 14 Biasing Pneumatic Relay provides versatility in its ability to provide either positive or negative biasing in a single unit.

The output of the Model 14 relay is the sum of the spring bias, set with the Range Screw, plus a pneumatic input signal. (Po = Ps + K); where Po is output pressure, Ps is signal pressure, and K is the combined spring constant.
Features
  • Control sensitivity of 1/2" water column allows use in precision applications
  • A balanced Supply Valve minimizes the effects of supply pressure variation
  • An Aspirator Tube minimizes downstream pressure droop under flow conditions
  • A separate Control Chamber isolates the diaphragm from the main flow to eliminate hunting and buzzing
  • Mounting Bracket is available 
  • Canadian Registration Number (CRN) certification for all territories and provinces

Specifications

Actuator Type

  • Knob Adjust
  • Tamper-Proof

Ambient Temperature Range

  • -40° to 93° C (-40° to 200° F)

BSP Connection

  • 1/2" BSPT Female
  • 1/4" BSPT Female
  • 3/8" BSPT Female

Elastomers

  • FluoroCarbon (Viton)
  • Nitrile on Dacron
  • Silicone

Enclosure, Body Material

  • Aluminum

Environmental Protection

  • Acceptable for use in Zones 1 & 2 for Gas Atmosphere, Groups IIA & IIB & Zones 21 & 22 for Dust Atmospheres

Exhaust Capacity - Relieving Units Only

  • 5.5 scfm
  • 5.5 scfm (9.35 m³/hour)
  • 9.4 m³/hour

Flow Capacity

  • 40 scfm
  • 40 scfm (68 m³/hour) psig: 100 (bar: 7, kPa: 700) Supply, psig: 20 (bar: 1.5, kPa: 150) Set Point
  • 68 m³/hour

Mounting

  • None

NPT Connection

  • 1/2" NPT Female
  • 1/4" NPT Female
  • 3/8" NPT Female

Pressure Range

  • bar: -1.2 to 0.7
  • kPa: -120 to 700
  • psig: -18 to 100

Relief

  • Non-Relieving
  • Relieving

Sensitivity

  • less than 1/2" WC (1.27 cm)

Signal or Output Pressure - Maximum

  • bar: 10
  • kPa: 1,000
  • psig: 150

Supply Pressure - Maximum

  • bar: 17
  • kPa: 1,700
  • psig: 250

Supply Pressure Effect

  • psig: 0.1 (bar: 0.007, kPa: 0.7) for a psig: 100 (bar: 7, kPa: 700) Change in Supply Pressure

Trim Material

  • Brass
  • Stainless Steel
  • Zinc-Plated Steel

Vent

  • Straight
  • Tapped Exhaust

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