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Bronze inline spring check valve with FNPT connections

Simmons

Simmons 503SB 1 in NPT bronze spring check valve .5 psi cracking pressure

SKU CH-J5W4-AC90S

Bronze inline spring check valve with .5 psi cracking pressure, Buna-N seal, stainless-steel spring and 400 psi water rating

  • Prevents backflow with .5 psi cracking pressure
  • Handles water systems up to 400 psi max pressure
  • Operates in temperatures up to 190 Degrees F
  • Durable bronze body with stainless steel spring
  • Installs horizontally or vertically for flexible piping

Product identity

The Simmons 503SB is a one-inch NPT bronze spring check valve with a .5 psi cracking pressure. It suits plumbing installers and maintenance crews who need reliable back-flow prevention in general-purpose water lines.

Sustained-load behaviour

The valve handles continuous water pressure up to 400 psi and fluid temperatures up to 190 degrees F. A stainless-steel spring and bronze seat maintain sealing force over long duty cycles without the pressure spikes that defeat lighter springs.

Build quality and connections

Bronze body construction with Buna-N seals resists corrosion in potable and non-potable systems. FNPT x FNPT threading allows direct inline installation in either horizontal or vertical orientation, and the 1 7/8 in length fits standard pipe runs without extra fittings.

Highlights

  • Prevents backflow with .5 psi cracking pressure
  • Handles water systems up to 400 psi max pressure
  • Operates in temperatures up to 190 Degrees F
  • Durable bronze body with stainless steel spring
  • Installs horizontally or vertically for flexible piping

Specifications

BrandSIMMONS

Questions about this item

How much heat can the bronze body and Buna-N seal handle during continuous operation?

The valve is rated for a maximum temperature of 190 degrees Fahrenheit, suitable for general-purpose water and air lines within that limit.

What pipe threads and sealing method are needed to install this 1-inch NPT valve?

It uses 1-inch FNPT x FNPT connections; apply thread sealant or tape on the male threads of the mating pipe or fitting to ensure a leak-free joint.

Will the .5 psi cracking pressure work with low-pressure gravity-fed systems?

Yes, the spring opens at just .5 psi, allowing flow in very low-head installations while still preventing backflow when pressure drops.

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