Conbraco 18C-521-5-125 Valve

The Conbraco 18C-521-5-125 is a professional-grade commercial temperature and pressure relief valve engineered for the protection of high-capacity hot water storage tanks and heaters. This Apollo TPC series relief valve features a robust bronze body and a 1-inch MNPT inlet by 1-inch FNPT outlet configuration, facilitating a secure fit in demanding piping environments. With a factory set point of 125 PSI and a maximum temperature threshold of 210°F, it provides reliable mechanical over-pressure and thermal protection. The integrated 5-inch probe length utilizes a specialized non-metallic coating to resist galvanic corrosion and mineral buildup, ensuring sensing accuracy over time. Rated for a massive 1,825,000 BTU capacity per ASME Section IV standards, this ASME certified T&P valve is the standard for contractors replacing failed safety devices in large-scale domestic water systems. Its automatic reseating capability and silicone seat ensure a tight seal and dependable performance after every discharge cycle.

Key Benefits

• Extreme Capacity: Rated for 1,825,000 BTUH, making it suitable for larger commercial water heaters.
• Corrosion Resistance: The 5-inch element is thermobonded with a protective coating to prevent electrolytic failure in aggressive water conditions.
• Precision Engineering: Features a silicone seat for superior high-temperature sealing and a stainless steel spring for consistent set-point reliability.
• Code Compliance: Fully ASME Section IV and CSA listed to meet stringent commercial building safety requirements.
• Direct Retrofit: Standard 1-inch NPT sizing allows for straightforward installation in existing commercial boiler and tank manifolds.

Common Questions

The 18C-521 features a Male NPT Inlet (MNPT), whereas the 18C-522 typically utilizes a Female NPT Inlet (FNPT). Always verify your manifold threading before selecting the part number.

The probe must be long enough to reach into the top six inches of the tank where the hottest water accumulates. The 5-inch length is the commercial standard for ensuring the thermal element reacts accurately to internal tank temperatures rather than ambient pipe temperature.

No, this T&P valve is specifically designed for commercial hot water heaters and storage tanks. For steam-specific safety requirements, an ASME Section I or VIII steam safety valve must be used.

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.