What is a compressor safety head?

• A. A thermal overload
• B. A check valve
• C. A spring on the valve plates
• D. A pressure relief valve on discharge

Answer: (C)

A compressor safety head is the spring-loaded arrangement on the valve plates. The springs bias the valve plates to seat when pressure drops and to control their movement when the piston creates discharge pressure. This spring mechanism helps prevent valve damage from rapid or excessive valve motion and protects the compressor head by absorbing shock and keeping the valves properly seated under changing pressures. The other items aren’t the safety head: a thermal overload protects the motor, a check valve prevents backflow, and a discharge pressure relief valve is a separate safety device for the system, not the valve-plate safety mechanism itself.