910028NT Scald Protection Valve

• Automatic scald protection — no electricity required – The thermostatic element responds purely to water temperature, closing the valve without any electrical connection, actuator, control signal, or user action when the water temperature exceeds the safe limit
• Full protection at 43.3°C with ±1°C accuracy – Precise thermostatic control ensures the valve shuts off reliably at the defined protection temperature, providing consistent safety performance across the valve’s service life
• Automatic self-reset when temperature drops – Once water temperature falls back below the protection temperature, the valve reopens automatically — no manual reset, no tool, and no service call required to restore normal operation
• Wide working temperature range of -30°C to 80°C – Suitable for installation in cold climate environments where ambient temperatures may drop below zero, as well as in hot water systems up to 80°C
• NPT thread specification – Available in 3/8 NPT and 3/4 NPT — the only Legom valve with NPT (National Pipe Thread) connections, providing direct compatibility with North American and international NPT plumbing systems
• High flow capacity at 20 L/min – Delivers up to 20 L/min at 300 kPa, supporting standard domestic hot water flow demands without restricting normal operation below the protection temperature
• 1 MPa maximum pressure rating – Suitable for standard domestic and commercial water supply pressures
• Brass construction – Durable and corrosion-resistant for long-term service in potable hot water systems

How to Read the Temperature Parameters

The three temperature values above follow standard wax thermostatic element convention and describe the travel of the thermostatic element, not the state of the water path. As the element extends, it drives the valve seat closed. Element “full open” at 43.3°C therefore corresponds to the water path being fully shut, which is the protective state.

Temperature Response Summary

Working principle per datasheet: when the water temperature rises to the protection temperature, the thermostatic element closes the valve and no water passes through. Once the water temperature falls below the protection temperature, the valve opens again and flow resumes. Refer to the datasheet flowing curve for pressure drop versus flow rate data.

• Solar water heating system outlet protection – Solar storage tanks can reach very high temperatures (60–80°C) during peak solar gain, and unlike a thermostatically controlled heater the output temperature is set by the weather rather than by the user. Installing the 910028NT downstream of the solar store provides automatic shutoff when the water temperature exceeds the safe delivery limit, preventing superheated water from reaching the user
• Electric storage water heater outlets – Applied as a safety valve on the outlet of electric water heaters where the accuracy of the heater’s own thermostat may vary or drift, providing an independent fail-safe temperature cutoff downstream of the tank
• Sanitary hot water safety in vulnerable user environments – Installed at shower, bath, or basin outlets in care homes, hospitals, schools, and facilities serving vulnerable users who may not be able to react quickly to unexpectedly hot water
• Heating and cooling system safety connections – Applied at terminal connections in hydronic heating systems where delivered water temperature must not exceed a defined limit before reaching user-side plumbing
• Independent backup to a thermostatic mixing valve – Fitted alongside a TMV as a second, independent layer of protection. A mixing valve is a control device that can drift out of calibration over years of service; a shut-off valve provides protection that remains effective if that drift occurs
• NPT plumbing systems in North American and international installations – The 3/8 NPT and 3/4 NPT thread options provide direct compatibility with North American plumbing standards, making the 910028NT appropriate for projects in markets where NPT threading is the standard

• Install with the 3/8 NPT end upstream (water inlet) and the 3/4 NPT end downstream (water outlet), as shown in the dimension drawing. Incorrect orientation will prevent correct thermostatic operation, and because water still passes through, the fault is not obvious on inspection
• Ensure the valve body is in direct contact with the flowing water whose temperature it is intended to sense. The thermostatic element inside the valve body must be fully wetted by the water stream for accurate temperature response. Avoid positions where air can be trapped around the element
• Use appropriate NPT thread sealant (PTFE tape or pipe dope rated for hot water service) on both thread connections. Do not overtighten — brass NPT threads can be damaged by excessive torque
• Do not install downstream of a mixing valve. Where a mixing valve has already reduced the water to the user delivery temperature, the 910028NT would only ever sense already-safe water and could never act if the mixing valve failed. It must sense the hot source temperature, so fit it upstream of the mixing valve or on a separate branch
• Keep the valve accessible for periodic verification and eventual replacement. Concealing it behind sealed panelling makes routine checking impractical
• After installation, verify correct operation by raising the hot water source temperature above the protection temperature and confirming that flow at the protected outlet stops, then confirming that flow resumes as the temperature falls back below the protection temperature
• The valve requires no maintenance under normal service conditions. In hard water areas, limescale accumulating around the thermostatic element is the most likely cause of gradual drift in the switching temperature. A valve that no longer shuts off at its rated temperature should be replaced rather than adjusted

Legom supports full OEM and ODM services for the 910028NT Scald Protection Valve. Customization parameters include water temperature range, open and close 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.