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Yellow cast iron flanged swing check valve, 4 inch

Milwaukee Valve

Milwaukee Valve 2974-M 4 inch flanged cast iron swing check valve

SKU CH-W78F-N3Q3C

A 4-inch flanged cast-iron swing check valve rated for 200 psi water and 125 psi steam with a bronze seat and chrome-cobalt seal

  • TypeOther
  • Reliable backflow prevention with inline swing mechanism
  • Durable cast iron body rated for 350°F max temperature
  • Flexible horizontal or vertical mounting orientation
  • Leak-tight seal from chrome and cobalt seat material
  • Handles up to 200 psi water pressure at 150°F

Application & Fit

This 4-inch flanged cast iron swing check valve suits commercial and industrial piping systems that require automatic back-flow prevention. Installers choose it for horizontal or vertical runs where a full-port inline swing design maintains flow capacity. It is not intended for residential fixtures or low-pressure domestic water lines.

Decisive Specification

The valve opens at a cracking pressure of .750 to 1.000 psi and seals against reverse flow up to 200 psi at 150 degrees F. Bronze seating and a chrome-cobalt seal deliver reliable shut-off within the stated pressure range. Systems that demand a lower cracking pressure or a higher pressure rating will need a different model.

Thermals, Noise & Power

Cast iron construction and the bronze seat tolerate continuous service from -20 degrees F to 350 degrees F, with a steam rating of 125 psi WSP. The swing mechanism operates passively without external power, so noise is limited to normal flow turbulence and the disc closing under gravity. No electrical supply or active cooling is required.

Highlights

  • Reliable backflow prevention with inline swing mechanism
  • Durable cast iron body rated for 350°F max temperature
  • Flexible horizontal or vertical mounting orientation
  • Leak-tight seal from chrome and cobalt seat material
  • Handles up to 200 psi water pressure at 150°F

Specifications

BrandMILWAUKEE VALVE
TypeOther

Questions about this item

How much pressure can the 200 psi rating actually hold when the system runs at 150 degrees F?

The valve is rated for 200 psi water pressure at 150 degrees F, so it will handle that pressure at that temperature.

What does the 125 psi WSP steam rating limit in daily use?

The 125 psi WSP rating caps the maximum steam pressure the valve can safely handle.

Will the 4 inch flanged ends line up with standard pipe flanges?

The valve uses a flange x flange connection for a 4 inch pipe size, matching standard flanged piping.

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