Bias Relay Pneumatic Relays and Volume Boosters

Positive Bias Relay -- Type 650
from ControlAir LLC

The Type-650 positive bias relay is a signal operated regulator that provides an output pressure that is the sum of the input signal pressure plus a preset bias. The unit allows flow capacity ties up to 50 SCFM with minimal pressure drop. An aspirator tube at the output maintains the set pressure... [See More]

  • Type: Bias Relay
  • Maximum Pressure: 250
  • Output Pressure: 15 to 150
  • Flow Capacity: 50
Pneumatic Relays -- Model 661
from Siemens Process Instrumentation

Series 661 Amplifying Relays are fixed-gain force-balance instruments, which incorporate bias adjustment that amplify pneumatic instrument signals. For example, a 3-15 psi signal can be amplified to operate a 3-27 psi control valve. The input pressure signal. acting upon the effective area of the... [See More]

  • Type: Bias Relay
  • Flow Capacity: 2.2
  • Maximum Pressure: 80
  • Port Size: 0.2500