Watts 0342629 Valve

The Watts 0342629 (Series 315-M2) is a high-capacity 3/4 inch steam safety relief valve specifically engineered for low-pressure steam heating boilers and commercial process equipment. This professional-grade valve is the direct updated version for 0342615, ensuring seamless Watts 315-15 compatibility for maintenance and replacement cycles. Constructed with a heavy-duty bronze body and a corrosion-resistant stainless steel spring, it is designed to meet strict ASME Section IV safety standards for saturated steam service.

Operating with a factory-set 15 PSI relief pressure, this unit delivers a certified discharge capacity of 375 lbs/hr. The technical design features a top-guided stem and a non-stick PTFE (Teflon) disc-to-metal seat, ensuring a positive shutoff and preventing the disc from adhering to the seat over time. The 3/4" MNPT inlet x 3/4" FNPT outlet configuration allows for straightforward installation into standard boiler headers and discharge piping. With a maximum temperature rating of 250°F, the 315M2-015 provides reliable overpressure protection for critical HVACR and industrial steam systems.

• ASME Section IV Certified: Validated for 375#/HR steam relief capacity, ensuring legal and safety compliance for 15 PSI systems.
• PTFE Disc-to-Metal Seating: Drastically reduces scaling and sticking issues common in low-pressure steam applications.
• Drop-in Replacement: Specifically designed to replace the legacy 0342615 without requiring piping modifications.
• Top-Guided Stem: Maintains precise alignment during high-velocity discharge to prevent seat damage.
• Bronze Construction: Superior fatigue and corrosion resistance compared to standard brass or iron alternatives.

Is the 0342629 compatible with my older 315-15 model?
Yes, the 0342629 is the manufacturer-designated update for the 0342615. It maintains the same 3/4" MNPT x FNPT dimensions and 15 PSI set point for direct field replacement.

What is the difference between a safety valve and a relief valve in this context?
For this Watts series, it is a safety valve designed to "pop" fully open once the 15 PSI set point is reached, providing rapid pressure relief for steam gases, whereas standard relief valves typically open proportionally for liquids.

Can I use this valve on a hot water boiler?
No, this model is specifically rated for steam service. Hot water systems typically require a Series 174A or similar T&P valve with a different BTU/hr rating and construction.

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.