Conbraco 10-301-10 Relief Valve

The Conbraco 10-301-10 is a high-capacity ASME Section IV hot water relief valve engineered for critical overpressure protection in hydronic heating systems and commercial boilers. This 3/4" NPT brass pressure relief valve features a 3/4" MNPT inlet and 3/4" FNPT outlet, factory-calibrated to a 50 PSI set pressure. Designed for heavy-duty service, it handles a maximum temperature of 250°F and delivers a high-volume 805,000 BTU/hr discharge capacity. The rugged bronze body construction and EPDM O-ring ensure a positive seal and reliable seat recovery after cycling. This Apollo 10-300 series valve is the industry standard for HVAC boiler safety valves, providing essential protection against thermal expansion and pressure spikes in closed-loop systems. Its compact profile allows for easy installation in tight mechanical rooms while meeting all National Board capacity certifications for commercial and residential hydronic applications.

• ASME Section IV Certified: Ensures compliance with local mechanical codes for hot water heating boilers and storage tanks.
• High BTU Rating: Provides 805,000 BTU/hr capacity, making it suitable for high-output commercial hydronic systems.
• Corrosion Resistance: Built with a heavy-duty bronze body and stainless steel spring for long-term durability in harsh water conditions.
• Reliable Reseating: Features a silicone seat and EPDM diaphragm for repeatable, leak-free performance after high-pressure events.

What is the difference between a safety valve and a relief valve?
This pressure relief valve is designed to open gradually as pressure increases above the 50 PSI set point, whereas safety valves typically pop fully open immediately. This unit is specific to liquid/hot water service.

Can the 10-301-10 be installed horizontally?
For proper HVAC safety valve installation and to ensure the seat drains correctly, this valve should be mounted in the vertical position with the discharge piping sloped for gravity drainage.

How do I size a replacement boiler relief valve?
Verify that the BTU discharge capacity of the valve matches or exceeds the gross heat output of the boiler while maintaining the correct NPT inlet size and pressure rating specified by the manufacturer.

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.