Watts 0382589 Valve

The Watts 0382589, also designated as model 740-1-40, is a high-capacity ASME Section IV iron body boiler pressure relief valve engineered specifically for hot water space heating applications. This 1" x 1.25" NPT valve is designed to protect hydronic systems from over-pressurization, featuring a set pressure of 40 PSI and a substantial steam discharge capacity of 1,600,000 BTU/hr. Its construction utilizes a rugged iron body with an expanded outlet to facilitate high-volume discharge without inducing backpressure on the system.

For veteran contractors, the Watts 740 series is preferred for its non-mechanical seat-to-disc alignment, which prevents sticking or freezing even in systems with intermittent cycling. The valve incorporates a non-metallic disc-to-metal seat and a stainless steel spring to resist corrosive water conditions and ensure positive reseating after emergency relief. To maintain seat integrity, the seat is located above the drain, ensuring that water and sediment cannot become trapped and foul the sealing surfaces. This unit serves as an emergency safety device and is intended for use in commercial and residential hot water boiler systems.

• High BTU Capacity: Rated at 1,600,000 BTU/hr to provide reliable safety relief for large-scale hydronic equipment.
• Enhanced Discharge: The expanded 1.25" outlet reduces discharge velocity and prevents restrictive backpressure.
• Corrosion Resistance: Features a stainless steel spring and non-metallic disc to prevent mineral build-up and sticking.
• Maintenance Friendly: Equipped with a heavy-duty test lever for standard annual safety inspections and operational verification.
• Fail-Safe Design: A high-temperature water seal isolates the internal spring from system fluid during relief events to prolong component life.

What is the difference between Watts 0382589 and 740-1-40?
These parts are identical. The numeric string 0382589 is the manufacturer ordering code, while 740-1-40 refers to the series, inlet size (1"), and PSI setting (40).

Can this relief valve be used as an operating control?
No. The Watts 0382589 is designed strictly for emergency pressure relief and should never be utilized for temperature or pressure regulation during normal operation.

Does this valve support flood sensing technology?
While the 0382589 was the standard mechanical version, newer iterations (often designated with an 'FS' suffix) support SentryPlus Alert technology. This specific iron body valve is primarily the mechanical safety component.

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.