WATTS Pressure Relief Valves for Water Heaters & Water Boilers - USA
WATTS Pressure Relief Valves for Water Heaters & Water Boilers - USA
Heavy-duty pressure protection for water heaters and water boilers. WATTS pressure relief valves help protect compatible hot-water equipment against excessive pressure. Made in USA. Choose the 3/4-inch, 125 PSI variant that matches your equipment’s connection and required relieving capacity.
Compare the two variants
| Specification | 008091F — Smaller | 007224F — Larger |
|---|---|---|
| Watts marking on supplied valve | 3L-M7 | LF474A |
| Inlet / outlet size | 3/4 inch / 3/4 inch | 3/4 inch / 3/4 inch |
| Connection | Male NPT inlet, female NPT outlet | Female inlet, female outlet |
| Pressure setting | 125 PSI (about 8.6 bar) | 125 PSI (8.61 bar) |
| Relieving capacity | 314,000 BTU/hr at 125 PSI (ASME) | 1,700,000 BTU/hr |
| Construction | Brass body, stainless steel spring, silicone disc | Lead-free bronze body, non-metallic disc-to-metal seat |
| Test lever | Included | Included |
| Application | Domestic storage tanks and tankless water heaters | Hot-water boiler pressure protection |
Product details
The compact 3L valve provides pressure-only relief without a temperature-sensing element. Watts lists the 3L family to ASME Section IV and ANSI Z21.22/CSA 4.4.
The higher-capacity LF474A has an elevated seat and a water seal that isolates its spring working parts from discharge water. Watts specifies a maximum temperature of 250°F (121°C) and maximum system operating pressure of 75% of its set pressure.
Installation overview
Connect the relief valve directly to the protected equipment without an intervening isolating valve. Run a full-size, unrestricted discharge pipe downward to a safe, visible disposal point. For the 3L, Watts specifies an open pipe end and an air gap of at least 6 inches (152 mm) above the building drain or approved discharge location. Do not connect the outlet directly to a sewer.
These are emergency safety devices, not operating controls. The illustration is a conceptual overview; follow the exact equipment manual, Watts instructions and local plumbing requirements.
Manufacturer references
Watts family identification follows the markings in the supplied photos; 008091F and 007224F are the supplied service-part references.
| Model |
008091F — Smaller, 007224F — Larger |
|---|