Conbraco 18C-521-5-150 Valve

The Conbraco 18C-521-5-150 is a high-capacity ASME Section IV certified primary safety device engineered for commercial hot water storage tanks and large-scale heating systems. Designed to prevent catastrophic vessel failure, this 1" MNPT x 1" FNPT temperature and pressure relief valve provides a 2,155,000 BTU/hr capacity, making it a standard for mechanical contractors servicing high-output boilers. The valve is factory set to open at 150 PSI or 210°F, utilizing a 5" probe length element that must be fully immersed in the top six inches of the water heater to ensure accurate thermal sensing.

Constructed with an ASTM B584 bronze body and brass seat stem, the 18C-500 series includes a non-metallic coating on the sensing element to isolate it from the water, effectively mitigating electromechanical corrosion. This model is CSA listed to ANSI Z21.22 and serves as a reliable T&P relief valve for commercial hot water systems demanding high-volume steam discharge during over-temperature or over-pressure events.

Key Benefits

• ASME Section IV Certified: Provides a rated 2,155,000 BTU steam relief capacity for large-scale commercial applications.
• Corrosion Resistance: Features a protective nylon element tube coating to prevent mineral buildup and galvanic action on the probe.
• Durable Construction: Built with a heavy-duty bronze body and silicone seat disc for long-term sealing performance and automatic reseating.
• Simplified Integration: Standard 1" male NPT inlet and 1" female NPT outlet allow for direct installation into tank tappings or hot water outlets.

Common Questions

What is the difference between the ASME and CSA ratings for this valve?
The Conbraco 18C-521-5-150 carries an ASME Section IV rating of 2,155,000 BTU/hr based on steam discharge, while its CSA capacity rating is 500,000 BTU/hr. Always size the valve based on the water heater's total BTU input to ensure the relief capacity exceeds the equipment's output.

How should the discharge line be piped for this 1" T&P valve?
The discharge line must be the same size as the valve outlet (1") and piped to a safe point of disposal. Use a material capable of withstanding 210°F and ensure the line pitches downward to allow for complete drainage, preventing water from being trapped and freezing.

Can I use this valve for potable water applications?
While designed for hot water heaters and storage tanks, verify local codes as some technical revisions regarding the Safe Drinking Water Act (SDWA) may require specific lead-free alloys for direct potable water consumption service in certain jurisdictions.

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.