Watson McDaniel Temperature Regulators

The W91/W94 Self-Operating Temperature Regulator is a mechanically operated device designed to regulate system temperature by modulating the flow of a heating or cooling fluid in response to temperature changes; requires no external power source. They are recommended for controlling temperature on relatively stable systems, where small valve stroke modulations will correct temperature drift. Where sudden or large load changes, or rapid temperature changes occur, a pneumatically-actuated Control Valve should be considered.

The W91/W94 Self-Operating Temperature Regulator is a mechanically operated device designed to regulate system temperature by modulating the flow of a heating or cooling fluid in response to temperature changes; requires no external power source.
Direct-Acting: Normally Open Valves are used for heating with STEAM. The actuators are designed to move the valve stem closed (in-to-close) as the control signal (temperature) increases.
Direct-Acting: Normally Open Valves are used for heating with LIQUID. The actuators are designed to move the valve stem closed (in-to-close) as the control signal (temperature) increases.
Reverse-Acting: Normally Closed Valves are used for COOLING, The actuators are designed to move the valve stem open (in-to-open) as the control signal (temperature) increases.
Mixing and Diverting: 3-Way Valves are used for mixing two flows together, or for diverting a flow to or around a device (bypass). In order to produce consistent flow quantity for stable operation, the pressure drop across both flow paths (inlet to outlet) must be equal. Do not use for steam applications.