Biasing pneumatic relay M14

control

Overview Designed for applications that require an output pressure equal to the sum of a controlled input signal and a fixed bias. The Rotork Fairchild Model 14 (M14) biasing pneumatic relay provides either positive or negative biasing in a single unit. Output pressure follows Po = Ps + K; where Po is output pressure, Ps is signal pressure, and K is the combined spring constant.

Key features

• Output equals spring bias (set with the range screw) plus pneumatic input signal (Po = Ps + K)
• Control sensitivity of 1/2" water column suitable for precision applications
• Balanced supply valve minimizes effects of supply pressure variation
• Aspirator tube design reduces downstream pressure droop under flow
• Separate control chamber isolates the diaphragm from main flow to prevent hunting and buzzing
• Mounting bracket available for field installation
• Certified for use in all Canadian territories and provinces

Technical specifications

• Model: M14 (Model 14) — Positive and Negative Bias Relay
• Function: Provides output pressure equal to signal pressure plus or minus a fixed spring bias (Po = Ps + K)
• Control sensitivity: 1/2" water column
• Design features: balanced supply valve; aspirator tube to minimize droop; separate control chamber to prevent hunting and buzzing
• Mounting: mounting bracket available for field installation
• Approvals: certified for use in all Canadian territories and provinces

Applications

• Industrial control systems and pneumatic positioners
• Process control and instrumentation requiring precise pressure biasing
• HVAC actuator control and valve automation