The Fairchild 90 Low Pressure Selector Relay is designed to select the lower of two signal pressures to provide a continuous output pressure to a control device.

The Fairchild 91 High Pressure Selector Relay is designed to select the higher of two signal pressures, and to provide a continuous output pressure (or pressure range) to a controller.

Features

• Small, rugged design suitable for installation where space is limited.
• Soft seat construction to assure positive shutoff.
• Low selection differential to allow precise control of switching.
• Fast response that is suitable for control in critical loops.
• Automatic switching that eliminates manual monitoring of signal pressure.

Specifications

Maximum Signal Pressure
200 psig, [14.0 BAR], (1400 kPa)
Minimum Switching Differential
Less than .1 psig, [.007 BAR], (.7 kPa)
Maximum Differential between Signals
100 psig, [7.0 BAR], (700 kPa)
Ambient Temperature Range
-40°F to +200°F, (-40°C to +93.3°C)
Materials of Construction
Body: Aluminum Alloy
Diaphragm: Dupont Fairprene-coated fabric
Trim: Brass

Fairchild 90:

Catalogue Pages including ordering details

Installation, Operation and Maintenance Instructions

Fairchild 91:

Catalogue Pages including ordering details

Installation, Operation and Maintenance Instructions