Description
W91 & W94 Series — Direct-Operated Temperature Regulators (Heating)
The W91 & W94 Series Temperature Regulators are direct-operated temperature control valves designed for heating applications in steam, hot water, and thermal fluid systems. These self-contained regulators automatically control flow to maintain a desired process temperature without the need for external power.
Reliable Heating Temperature Control
The W91 & W94 Series regulators use a liquid-filled sensing bulb and capillary system to respond accurately to temperature changes. As process temperature drops below the set point, the valve opens to increase heating medium flow. As temperature rises, the valve modulates closed to maintain precise and stable temperature control.
Material Specification
- Valve Body: Bronze
- Thermal Actuator: Copper bulb with capillary
Technical Specification
- Service: Heating applications
- Temperature Ranges: 20°F to 450°F (depending on selected range)
- Maximum Operating Pressure: Up to 250 PSIG
- Sizes: 1/2" through 4"
- Connections: NPT, 125# Flanged
- Operation: Direct-operated, self-contained
Operating Principles
The sensing bulb is installed at the point where temperature control is required. When the sensed temperature falls below the set value, the fluid inside the bulb contracts, causing the actuator to open the valve and allow additional heating medium flow. As temperature increases toward the set point, the actuator pressure rises and the valve closes proportionally to maintain consistent heating control.
W91 & W94 Series Models
The W91 Series is supplied with a non-indicating dial actuator, while the W94 Series includes an indicating dial actuator for direct temperature reference. Various temperature ranges, valve sizes, and capillary lengths are available to accommodate diverse heating system requirements.
Applications
- Steam and hot water heating systems
- Heat exchangers
- Process heating equipment
- Jacketed vessels and tanks
- Industrial and commercial heating systems
Notes
Valve bodies used for heating service carry an “H” designation in the model code. Thermowells are ordered separately. Proper selection of temperature range, bulb type, and capillary length is essential for accurate temperature control. Consult factory for sizing, options, or special heating applications.