Pressure Reducing Valve

Introduction to Pressure Reducing Valves

A Pressure Reducing Valve (PRV) is used to lower and maintain stable downstream pressure in piping systems, even when inlet pressure or flow demand changes. This device helps protect pipelines and downstream equipment from overpressure, reduces leakage risk, minimizes water hammer, and extends the service life of the entire system. With its automatic operating principle, a PRV does not require external power and responds directly to actual pressure conditions inside the pipeline.

Among pressure control products, Watts pressure reducing valves stand out for their compliance with international standards and their ability to maintain accurate, stable outlet pressure. Watts PRV models are engineered for durable materials, flexible adjustment, and long-term performance under continuous operating conditions.

Operating Principle of Pressure Reducing Valves

A pressure-reducing valve balances pressure automatically using the interaction of fluid pressure, an adjustment spring, and an internal control assembly. The valve continuously senses downstream pressure and adjusts its opening to maintain the preset outlet pressure. Requiring no external power, it suits systems that need stable and continuous performance.

During operation, the valve responds directly to pressure and flow changes in the pipeline:

• When the inlet pressure increases: Higher pressure acts on the control mechanism, narrowing the valve opening. Flow decreases, bringing downstream pressure to a safe level.
• When outlet pressure drops below the setpoint: The adjustment spring opens the valve mechanism further, allowing more fluid to pass and restoring downstream pressure.
• When demand flow changes suddenly: The valve modulates its opening to compensate, maintaining stable outlet pressure and limiting system fluctuation.
• When the system reaches balance: The spring force and downstream pressure equalize, holding the valve in position until the next pressure change occurs.

Watts Pressure Reducing Valve Product Line

To meet a wide range of pressure control requirements in piping systems, Watts offers various pressure reducing valve series with different designs and application ranges. Each product is engineered for specific operating conditions, allowing more accurate selection and more efficient performance in real-world installations.

Series PRVA

The PRVA series is a pressure reducing valve from Watts designed for water supply systems, helping control and stabilize inlet pressure before distribution to downstream fixtures and equipment. It is intended for residential systems, apartments, and small commercial buildings where stable pressure, quiet operation, and reliable performance are required. Compared with many standard pressure reducing valves, the PRVA stands out for its compact design, high flow capacity in a small body, flexible pressure adjustment, and convenient in-line maintenance. This makes it a practical solution for systems focused on long-term operating efficiency.

Below are the key technical specifications of the PRVA series:

• Valve size: DN15 – DN20
• Body material: Brass CW602N
• Maximum working pressure:
  • PRVAS15F & PRVAS20F: up to 2000 kPa
  • PRVAR20F & PRVAR20F Press Fit: up to 1600 kPa
• Pressure reducing range: 150 – 600 kPa
• Temperature range: 0.5°C to 80°C
• Connection types:
  • BSP threaded
  • Compression connection
  • Press Fit connection
• Certification: WaterMark 

Series LFN45BM1/LFN45B

The LFN45BM1 / LFN45B series is a specialized pressure reducing valve from Watts, designed to control and stabilize pressure in water supply and water treatment systems. The valve stands out with a lead-free silicon bronze body, integrated stainless steel strainer, and in-line serviceable construction. Its sealed spring cage and thermal expansion bypass feature help maintain stable performance under various installation conditions. This series is a reliable solution for projects requiring long service life and dependable operation.

Below are the key technical specifications of the LFN45BM1 / LFN45B series:

• Valve size:
  • DN15 – DN25
  • DN32 – DN50
• Body material: Lead-free bronze
• Nominal pressure:
  • LFN45BM1 (DN15-DN25): 400 psi (2.76 MPa)
  • LFN45B (DN32-DN50): 300 psi (2.07 MPa)
• Pressure reducing range: 25 – 75 psi (172 – 517 kPa)
• Temperature range: 0.5°C to 82°C
• Design standards: ASSE 1003, ANSI A II 2.26.2, CSAB356, IAPMO
• Connection standard: NPT to ASME B1.20.1
• Working medium: Water
• Certifications: ASSE, CSA, UPC, NSF

Toan Cau – Exclusive Distributor of Watts Pressure Reducing Valves

Watts pressure reducing valves are designed to maintain stable pressure, protect equipment, and extend the service life of piping systems. These PRV products meet international technical standards and suit applications ranging from residential water supply to commercial systems and technical infrastructure. Their reliable performance makes them a trusted choice for engineers and contractors.

In Vietnam, Toan Cau Building Materials Co., Ltd. serves as the exclusive distributor of Watts Water Technologies pressure reducing valves, supplying genuine products with full technical support. The company also carries other Watts product lines: backflow preventers, automatic control valves, check valves, balancing valves, safety valves,… To request product selection assistance or a quotation, call hotline 0911 771 551.