Watts 530 3/4 MNPT x 1/2 FNPT Relief Valve 50-175 psi
A calibrated adjustable relief valve with brass body and stainless steel spring, adjustable from 50 to 175 psi for commercial, industrial, oil/air and residential systems
- Adjustable pressure control with 50 to 175 psi range
- Factory calibrated at 150 psi for immediate installation
- Brass body resists corrosion in commercial and residential systems
- Stainless steel spring maintains consistent performance up to 180 °F
- Buna-N disc and seat provide reliable sealing across oil, air and water applications
Watts 530 Adjustable Relief Valve
This Watts 530 calibrated adjustable relief valve protects residential, commercial, industrial and oil or air systems from over-pressure conditions. The brass body handles a factory-set pressure of 150 psi and an adjustable range from 50 to 175 psi. It operates reliably across temperatures from 0 to 180 degrees Fahrenheit. The valve suits installations where a compact, field-adjustable safety device is required.
Brass Construction with MNPT and FNPT Connections
The valve body is brass with a Buna-N disc and seat plus a stainless-steel spring for corrosion resistance. A 3/4-inch male NPT inlet threads into the system piping while a 1/2-inch female NPT outlet accepts the discharge line. Overall height is 3 inches and overall length is 1 5/8 inches, allowing installation in tight mechanical rooms. No test lever is included so periodic testing must be arranged separately.
Verify Pressure, Temperature
Confirm the system design pressure falls within the 50 to 175 psi adjustable range and that the maximum operating temperature does not exceed 180 degrees Fahrenheit. Ensure the piping can accommodate a 3/4-inch male NPT inlet and a 1/2-inch female NPT outlet with the stated overall dimensions. The Buna-N disc and seat limit fluid compatibility so check suitability for the specific media before ordering.
How it compares
Measured against everything we stock in Bath Accessories & Soap Dispensers, at today’s prices. Recalculated every night.
- Price $75.99
- Pricier than about 67% of the 1,499 comparable items (median $39.99).
Specifications
| Product | |
|---|---|
| Brand name | WATTS |
| Product type | Other |
Questions about this item
What pressure range does the 530 relief valve cover, and what is the factory set point?
The valve adjusts from 50 to 175 psi and ships calibrated at 150 psi.
What pipe threads are required for the 3/4 in MNPT inlet and 1/2 in FNPT outlet?
The inlet needs a 3/4 in female NPT fitting; the outlet accepts a 1/2 in male NPT fitting.
How is the 530 valve installed, and what step is commonly missed?
Thread the MNPT inlet into the system using pipe sealant, orient the FNPT outlet downward for drainage, and remember the test lever is not included so a separate lever must be sourced for manual testing.
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