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WattsASME Section XIII Hot Water Pressure Relief Valves

WATTS RELIEF VALVE: NPTF x NPTF, 3/4 in x 3/4 in, Iron, 40 psi Max. Op Pressure

The Watts 3/4 in x 3/4 in NPTF x NPTF Relief Valve (MPN F358551) is an ASME Section XIII hot water pressure relief valve constructed of iron with a maximum operating pressure of 40 psi and an overall height of 3 1/2…

SKU 3G-OTH-442529

Also listed as: F 358551 · F-358551

Brand
Watts
Item
RELIEF VALVE: NPTF x NPTF, 3/4 in x 3/4 in, Iron, 40 psi Max. Op Pressure
Category
ASME Section XIII Hot Water Pressure Relief Valves
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Technical Specifications

Watts
Manufacturer Part Number
F358551
Type
3/4 in x 3/4 in, Iron
Overall Ht
3 1/2 in
Max. Op Pressure
40 psi

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Watts Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The Watts 3/4 in x 3/4 in NPTF x NPTF Relief Valve (MPN F358551) is an ASME Section XIII hot water pressure relief valve constructed of iron with a maximum operating pressure of 40 psi and an overall height of 3 1/2 in. 3G Electric interprets demand for this genuine Watts safety component across 14 industrial departments, with specialist depth in combustion, pumps and controls as an authorised distributor.

Frequently Asked Questions

What is the Watts F358551 relief valve used for?

The Watts F358551 is an ASME Section XIII hot water pressure relief valve used in hydronic heating systems and water heaters. It automatically opens to discharge water when system pressure exceeds 40 psi, preventing overpressure damage. Common applications include commercial and residential boiler installations.

What are the specifications of the Watts F358551 relief valve?

The Watts F358551 has a 3/4 in NPTF x 3/4 in NPTF connection, iron body, 40 psi maximum operating pressure, and 3 1/2 in overall height. It is an ASME Section XIII hot water pressure relief valve. The manufacturer part number is F358551.

Where to buy the Watts F358551 relief valve worldwide?

3G Electric supplies the Watts F358551 relief valve worldwide. As a global industrial equipment distributor since 1990, we handle full logistics, customs clearance, and delivery to your location. Contact us for availability and lead time. We source and deliver this ASME-rated valve to any country.

How to install the Watts F358551 relief valve?

Install the Watts F358551 relief valve in the hot water system discharge line with the inlet connected to the system and outlet open to atmosphere. Ensure no shutoff valve is placed between the valve and system. Follow local plumbing codes and ASME guidelines. Use thread sealant on NPTF connections and test after installation.

Used in

Common applications for Watts
Industrial burner gas safety systems — Watts HF2000 filters with GF-series seal kits maintain clean, regulated gas supply to burner pilot and main flame controls
Commercial heating and boiler installations — Modular filter assemblies support preventive maintenance and component replacement without full system shutdown
Process gas delivery pipelines — DN25 through DN125 filter bodies accommodate varying flow rates and inlet pressures across manufacturing and chemical processes
Gas pressure regulation benches — Multi-stage Watts filter platforms integrate with pressure reducers and safety shutoff valves in test and calibration environments
Equipment retrofit and upgrade projects — Available connection sizes and seal kits enable adaptation of newer Watts components into legacy gas control systems
Planned maintenance and spare-parts inventory — Filter seal kits allow facilities to stock consumables in advance, reducing downtime during scheduled gas system servicing

Watts Products

3G Electric supplies Watts asme section xiii hot water pressure relief valves. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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Cross-referenced by specification & description
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WATTS RELIEF VALVE: NPTF x NPTF, 1 1/2 in x 2 in, Iron, 30 psi Max. Op Pressure, 9 1/4 in Overall Ht (MPN F383740)
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WATTS Pressure Relief Valve: FNPTF x FNPTF, 3/4 in x 3/4 in, Iron, 10 psi Max. Op Pressure (MPN 0358551)
WATTS Pressure Relief Valve: FNPTF x FNPTF, 1 1/2 in x 2 in, Iron, 40 psi Max. Op Pressure (MPN F383792)
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WATTS Pressure Relief Valve: FNPTF x FNPTF, 1 1/2 in x 2 in, Iron, 40 psi Max. Op Pressure (MPN F383792)
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WATTS Boiler Pressure Relief Valve: FNPTF x FNPTF, 3/4 in x 1 in, Iron, 40 psi Max. Op Pressure (MPN F382328)

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