Flomatic 4221MP 100MP 1 1/4" M x 1" F Plastic Check Valve

The Flomatic 4221MP 1 1/4" M x 1" F 100MP plastic check valve is a compact, high-strength thermoplastic check valve designed to help maintain system pressure, prevent backflow, and protect downstream components. This model features a unibody Noryl® GTX 830 body with a Nitrile (Buna-N) seal, a Hostaform® poppet head with polypropylene follower, and a 302 stainless-steel spring in a stemless, anti-spin design. The threaded male x female NPT connection allows for easy installation in a variety of plumbing and water system layouts, and the valve is rated for a maximum working pressure of 300 psi and a maximum temperature of 150°F (65°C).

Specifications:

Max Pressure: 300 psi (21 bar)

Max Temperature: 150°F (65°C)

Body: High-strength Noryl® GTX 830 thermoplastic, unibody design

Seal: Nitrile (Buna-N)

Poppet: Hostaform® resin dome with polypropylene follower

Spring: 302 stainless steel, large diameter for even spring load and long life

Cracking Pressure: 0.25 psi

Flow Coefficient (Cv): 12

Electrical: Non-conductive design helps eliminate electrolysis

Connection: 1 1/4" M x 1" F NPT

Weight: 0.17 lbs

Operation: Flomatic 100MP plastic check valves are designed to provide years of trouble-free operation when properly sized and installed in suitable water and plumbing systems. The internal spring-loaded poppet closes quickly at low reverse flow to help minimize backflow, water hammer, and pressure loss, while the low head loss design supports efficient system performance.

Construction: The unibody thermoplastic construction provides high tensile strength (up to 4000 lb maximum tensile load) and resistance to common installation materials such as pipe dope. The non-conductive body helps eliminate electrolysis in mixed-metal piping systems, and the stemless, anti-spin poppet design helps ensure smooth, reliable operation over the life of the valve.

The stainless-steel spring and internal hardware, combined with the engineered plastic body and poppet materials, provide excellent resistance to corrosion and wear in demanding water and plumbing environments.

Applications: Residential and light commercial plumbing systems, water pressure maintenance, general utility water lines, and applications requiring a compact, non-metallic check valve.

Model 4221MP 100MP includes a 1 1/4" male NPT x 1" female NPT thermoplastic body for easy inline installation.