910026NT Freeze Protection Valve
The Legom 910026NT Freeze Protection Valve is a self-acting thermostatic safety valve designed to protect water pipes from freezing damage. When water temperature drops toward freezing point, the internal thermostatic element automatically opens the valve — allowing water to drain from the pipe before it can freeze. Once temperature recovers above the threshold, the valve closes automatically and normal pipe operation resumes. No electricity, no manual intervention, and no external control are required.
With an initial open temperature of 1.6°C, full open at 4°C, and full close at 7°C, the 910026NT activates very close to the freezing point of water — releasing just enough flow to prevent static water in the pipe from reaching 0°C and expanding into ice. Available in G3/8-19 and G3/4-14 thread specifications, with a maximum flow of 20 L/min at 300 kPa, maximum pressure of 1 MPa, and control accuracy of ±1°C. The valve is suitable for outdoor pipework, exposed cold-climate plumbing, solar and electric water heating systems, and any installation where pipes may be exposed to sub-zero ambient conditions.
Key Benefits
- Automatic freeze protection — no electricity required – The thermostatic element responds purely to water temperature, opening the valve without any electrical connection, actuator, or control signal when water approaches freezing point
- Opens at 1.6°C — activates before freezing damage occurs – Initiates drainage before water reaches 0°C, providing a safety margin that accounts for the ±1°C control accuracy and prevents ice formation before the valve can respond
- Self-closing at 7°C — minimal water waste – The valve closes automatically once temperature recovers to 7°C, limiting the total volume of water drained to the minimum necessary for freeze protection and restoring normal pipe pressure automatically
- Working temperature range of -30°C to 80°C – The valve body and thermostatic element maintain structural integrity and correct function across extreme cold ambient conditions, down to -30°C, ensuring protection even in severe cold climates
- G thread connections for international compatibility – G3/8-19 and G3/4-14 parallel pipe thread connections compatible with European and international plumbing standards
- High flow capacity at 20 L/min – Provides sufficient drainage flow rate to depressurize and drain the at-risk pipe section quickly when freezing conditions are detected
- 1 MPa maximum pressure rating – Suitable for standard domestic and commercial water supply pressures
- Brass construction – Durable and corrosion-resistant for long-term outdoor and cold-climate service
- OEM and ODM customization available – Temperature thresholds, pressure rating, and connection size can be customized for specific applications
Technical Specifications
| Parameter | Specification |
|---|---|
| Model | 910026NT |
| Material | Brass |
| Initial Open Temperature | 1.6°C |
| Full Open Temperature | 4°C |
| Full Close Temperature | 7°C |
| Working Temperature | -30°C to 80°C |
| Max Pressure | 1 MPa |
| Max Flow | 20 L/min (at 300 kPa) |
| Control Accuracy | ± 1°C |
| Thread Specification | G3/8-19 / G3/4-14 |
| Dimensions | 95.5 ± 0.5mm (H); 3/8″-18NPT top, 3/4″-14NPT bottom |
Temperature Response Summary
| Water Temperature | Valve State | Water Flow |
|---|---|---|
| Above 7°C | Fully closed | No flow — normal pipe operation |
| 1.6°C – 7°C | Progressively opening | Increasing drainage flow |
| 4°C and below | Fully open | Maximum drainage flow — freeze protection active |
| Recovering above 7°C | Closing | Flow reducing — valve returning to closed |
910026NT vs 910028NT — Complementary Protection Valves
| Parameter | 910026NT (Freeze Protection) | 910028NT (Scald Protection) |
|---|---|---|
| Opens when | Temperature drops (cold) | Temperature rises (warm) |
| Closes when | Temperature rises (above 7°C) | Temperature drops (below 35°C) |
| Protection against | Pipe freezing | Inadequate hot water delivery |
| Initial open | 1.6°C | 36.7°C |
| Thread | G3/8 / G3/4 | NPT 3/8 / 3/4 |
Application & Use Cases
- Outdoor exposed pipework in cold climates – The primary application. Garden taps, outdoor shower connections, irrigation supply pipes, and external wall pipe runs that cannot be adequately insulated against frost are protected by the 910026NT draining the at-risk section automatically when ambient temperature causes water to approach freezing point
- Solar thermal collector pipe protection – Solar collector pipework on roofs and in exposed locations is particularly vulnerable to freeze damage in winter. The 910026NT drains the collector loop automatically when water temperature drops toward freezing, preventing ice damage to the collector tubes and connections
- Heat pump outdoor unit pipe connections – Pipework connecting outdoor heat pump units to indoor heating circuits passes through areas exposed to winter ambient temperatures. The 910026NT protects these connections from ice damage during extreme cold events or system shutdowns
- Unheated building pipe protection – Water supply pipes in unheated garages, outbuildings, summer houses, and vacant properties are vulnerable to freezing during winter. The 910026NT provides automatic protection without requiring any human presence or intervention
- Irrigation and garden water supply systems – End-of-season or unexpected frost events can freeze garden water supply pipes. The 910026NT provides continuous automatic protection without requiring seasonal manual valve operation
- Vacation homes and seasonal properties – Properties left unoccupied during winter benefit from automatic freeze protection without relying on occupants to drain the system before leaving or return before freezing damage occurs
Installation Notes
- Install the 910026NT at the lowest accessible point of the pipe section requiring freeze protection, oriented so that gravity assists drainage when the valve opens
- The valve outlet must drain to a location where released water will not cause damage — to a drain, soakaway, or safe outdoor ground area. Do not install where drainage flow will pool against foundations or cause flooding
- Ensure the valve body is in direct contact with the water in the pipe whose temperature it is intended to sense. The thermostatic element inside the valve must be fully wetted for accurate temperature response
- The valve should be installed in the at-risk pipe section — not in a heated or insulated area where it will not experience the freezing temperatures that trigger its opening
- Use appropriate thread sealant on the G3/8 or G3/4 thread connections. Verify thread compatibility before installation — the datasheet dimension drawing shows NPT dimensions; confirm the thread specification for your application with the Legom team
- After installation in autumn or before the frost season, test the valve by briefly cooling the pipe section with cold water or ice to confirm the valve opens at the correct temperature and drains freely
- No routine maintenance is required under normal service conditions. Inspect annually before the frost season to confirm the valve outlet is unobstructed and the valve body is free of scale or corrosion
Frequently Asked Questions
How does the 910026NT differ from the 910078NT Anti-Freeze Valve?
Both valves protect pipes from freezing, but they use different mechanisms. The 910078NT is a wax thermostatic element-actuated anti-freeze valve that opens a bypass or drain path when water temperature drops to near-freezing, using a wax element as the actuating mechanism. The 910026NT uses a thermostatic element integrated directly into the valve body to provide the same temperature-sensing and drain-opening function in a more compact inline form factor. The 910026NT also provides a detailed temperature profile (initial open 1.6°C, full open 4°C, full close 7°C) and a published flow curve, giving installers more precise data for system design.
How much water does the valve drain when it opens?
The valve drains continuously while open — flow increases from initial opening at 1.6°C to maximum flow at 4°C and below. At 300 kPa supply pressure, maximum flow is 20 L/min. In practice, the supply water flowing into the pipe from the mains as drainage occurs will itself warm the pipe water above the closing threshold relatively quickly, limiting the total volume drained per freeze event. The exact volume depends on supply pressure, pipe volume, and ambient temperature. A drainage point capable of handling 20 L/min should be provided.
Does the valve require manual resetting after a freeze event?
No. The 910026NT is fully self-resetting. Once water temperature recovers above 7°C — whether from warmer ambient conditions, warming supply water flowing through the pipe during drainage, or heat conducted from adjacent heated areas — the valve closes automatically. Normal pipe pressure is restored without any manual intervention.
Can the valve be installed in a heated area?
If the valve is installed in a heated area, the thermostatic element will sense the ambient temperature of the heated space rather than the temperature of water in the at-risk pipe section. In this case, the valve will remain closed even if the pipe outside the heated area is freezing. The 910026NT must be installed in the at-risk pipe section itself — exposed to the same ambient conditions as the pipe it is protecting — for the thermostatic element to respond correctly.
Can the 910026NT be customized for different freeze protection thresholds?
Yes. Legom offers OEM and ODM customization including open and close temperature thresholds, pressure rating, connection size, and body material. This is relevant for applications in extremely cold climates where the standard 1.6°C initial open may not provide sufficient advance warning, or for fluids other than water with different freezing points. Contact the Legom team with your requirements.
OEM & ODM Customization
Legom supports full OEM and ODM services for the 910026NT Freeze Protection Valve. Customization parameters include temperature thresholds, pressure rating, connection size, and body material. All customization projects are handled with strict confidentiality. Contact us via WhatsApp or info@legomsmart.com.
Datasheet
Product information last reviewed by the Legom Technical Team. For the most current specifications, refer to the official datasheet or contact our sales team.
Custom OEM & ODM Solutions
Legom is a direct manufacturer offering end-to-end OEM and ODM services. With our in-house engineering and production capabilities, we work closely with distributors and system integrators to deliver fully customized solutions under strict NDA.
