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Bronze inline spring check valve with FNPT connections

Simmons

Simmons 504SB Bronze Spring Check Valve 1-1/4" FNPT .5 psi

SKU CH-GY9Y-73PD4

Bronze inline spring check valve with Buna-N seal, 0.5 psi cracking pressure, rated to 400 psi water and 190 °F

  • Prevents backflow with a .5 psi cracking pressure
  • Bronze body resists corrosion in plumbing systems
  • Stainless steel spring ensures reliable long-term operation
  • Installs horizontally or vertically for flexible piping
  • Rated to 400 psi water pressure for demanding applications

Simmons 504SB Bronze Spring Check Valve

The Simmons 504SB is a 1-1/4 inch FNPT bronze inline spring check valve built for general-purpose fluid control. Its bronze body and Buna-N seal handle water pressure up to 400 psi and temperatures up to 190 degrees Fahrenheit. A stainless steel spring provides the closing force with a low cracking pressure of .5 psi. The valve installs in either horizontal or vertical orientation.

Suited for low-pressure water lines

This valve suits installers who need a compact bronze check valve with a very low cracking pressure for water or compatible fluids. It is not rated for steam service, so systems carrying steam should look elsewhere. Buyers requiring a higher cracking pressure or a different seal material will need a different model.

Cracking pressure of .5 psi

The single specification that determines fit is the .5 psi cracking pressure, which sets the minimum upstream pressure required to open the valve. If the system cannot reliably exceed this pressure, the valve will not function as intended. Verify the required cracking pressure before purchase.

Highlights

  • Prevents backflow with a .5 psi cracking pressure
  • Bronze body resists corrosion in plumbing systems
  • Stainless steel spring ensures reliable long-term operation
  • Installs horizontally or vertically for flexible piping
  • Rated to 400 psi water pressure for demanding applications

Specifications

BrandSIMMONS

Questions about this item

Will the .5 psi cracking pressure let my existing low-head pump prime without fighting the spring?

The .5 psi cracking pressure is very low, so the spring opens with minimal head pressure and will not prevent an existing low-head pump from priming.

How can I confirm the Buna-N seal is holding at my system's 190 °F water temperature?

Pressurize the line to working pressure and inspect the FNPT joints; no leakage at 190 °F means the Buna-N seal and bronze seat are functioning correctly.

Does the box include pipe-thread sealant or must I buy thread tape for the FNPT connections?

Only the bronze valve body with stainless-steel spring is supplied; thread sealant or tape for the 1-1/4" FNPT ends must be purchased separately.

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