Conbraco 18C-511-3-125 Valve

The Conbraco 18C-511-3-125 is a high-capacity temperature and pressure relief valve designed specifically for heavy-duty commercial water heating systems. Featuring a 3/4" male NPT inlet and a 3/4" female NPT outlet, this valve is engineered to provide reliable thermal protection by discharging water when pressure exceeds 125 PSI or temperatures reach 210°F. With a discharge capacity of 1,619,000 BTU, it meets the rigorous demands of large boilers and storage tanks. The 3-inch extension probe ensures accurate thermal sensing within the tank's top six inches, where the hottest water resides. Built with a bronze body and stainless steel springs, this valve resists corrosive buildup, ensuring consistent seat alignment and disc reseating during high-cycle operations. For contractors, this T&P valve provides a field-proven solution for ASME Section IV compliance in potable water heating applications.

• Maximum Thermal Protection: Rated for systems up to 1,619,000 BTU/HR to prevent catastrophic tank failure.
• Corrosion Resistance: Lead-free bronze body and stainless steel components ensure longevity in aggressive water conditions.
• Precise Calibration: Factory-set at 125 PSI and 210°F to maintain system safety margins without premature lifting.
• Standardized Fitment: The 3/4" NPT connections allow for straightforward integration into existing headers and water heater ports.

Common Technical Questions

Can this valve be installed horizontally?
This valve is designed for vertical installation on the top of the water heater or in a side tapping within the top six inches of the tank to ensure the 3" probe is properly submerged in the hottest water.

What causes the valve to weep or drip?
Weeping usually indicates thermal expansion in a closed system or debris trapped on the seat. Check your expansion tank pressure before replacing the valve, as the 125 PSI threshold may be reached during heating cycles.

Is this model suitable for steam heating boilers?
No, the 18C series is specifically for hot water supply boilers and storage tanks. For steam applications, an ASME Section I or VIII safety plate valve is required.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.