Watts 0383310 Valve

The Watts 0383310 (Model 740-1 1/4-50) is a high-capacity ASME Section IV heating boiler safety relief valve designed for overpressure protection in large-scale commercial and industrial hydronic heating systems. Featuring a 1-1/4 inch NPT threaded inlet and outlet, this iron body safety relief valve is engineered for heavy-duty performance with a factory-set pressure of 50 PSI. It delivers a high-volume discharge capacity of 3,075,000 BTU/hr, ensuring compliance with strict safety standards for hot water heating boilers. The valve utilizes a non-stick Teflon disc-to-metal seat to prevent leakage and ensure reliable opening during pressure spikes. For contractors managing large boiler rooms, the Watts 740 series provides the necessary durability and BTU relief capacity required for high-output applications. Its side-outlet design and top-lifting lever allow for straightforward maintenance and testing, ensuring the integrity of the secondary pressure system.

• High BTU Relief Capacity: Rated at 3,075,000 BTU/hr to protect large commercial hydronic systems.
• Durable Construction: Features a rugged iron body designed to withstand demanding mechanical room environments.
• High-Temperature Seat: Equipped with a Teflon-coated disc to ensure a bubble-tight seal and resist sticking.
• ASME Certified: Meets Section IV requirements for pressure vessel safety and system compliance.
• Standard Connection: 1-1/4 inch NPT threaded connections facilitate easy integration with existing iron pipe schedules.

Common Questions

What is the pressure setting for the Watts 0383310?
This specific model is calibrated and factory-set to a relief pressure of 50 PSI. It is essential to verify that your boiler's Max Allowable Working Pressure (MAWP) exceeds this setting before installation.

Can the 740 series valve be installed in any orientation?
To maintain proper safety relief valve performance, the unit must be installed with the spindle in a vertical position. Horizontal installation can lead to sediment buildup and prevent the seat from sealing correctly.

What is the difference between the 740 and 174A series?
The Watts 740 series is designed for high-capacity applications with significantly higher BTU ratings than the 174A series, making it the preferred choice for commercial-scale boilers.

This item is not eligible for free shipping.

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.