Milwaukee Valve 509y - 114 Bronze Swing Y Check Valve

Product Description

The MILWAUKEE VALVE 509y - 114 is a 1-1/4 inch Y-pattern swing check valve with a cast bronze body and bronze seat, designed to allow single-direction flow while preventing backflow in plumbing, steam, and process piping systems. The FNPT x FNPT connections make it straightforward to install inline in threaded pipe runs. With a cracking pressure of 0.5 psi and a full-flow rating of 54 gpm, this valve opens easily under low differential pressure and keeps flow restriction minimal. Maximum operating pressure is 200 psi WOG at 150 degrees F, and the valve is rated for steam service at 125 psi WSP. Plumbers and pipefitters working on commercial and industrial systems will find the Y-body design reduces turbulence and pressure drop compared to traditional swing check configurations.

This valve is suited for general-purpose service across water, steam, oil, and gas lines in both horizontal and vertical mounting orientations. The Y-pattern body allows the swing disc to travel in line with flow, making it well-suited for higher-velocity or pulsating flow conditions. Typical installation scenarios include boiler feed lines, hot and chilled water systems, steam distribution piping, compressed air lines, and fuel-oil supply runs in commercial and light industrial facilities. The temperature rating spans -20 degrees F to 425 degrees F, covering a broad range of steam and process applications.

Key Features

• Y-swing check mechanism allows near-axial disc travel, reducing flow turbulence and pressure drop
• Cast bronze body with bronze seat and seal rated for water, steam, oil, and gas media
• Low 0.5 psi cracking pressure for minimal resistance in low-differential-pressure systems
• Full-flow design rated at 54 gpm with a Cv of 39
• Mounts in horizontal or vertical pipe runs without orientation restriction
• Manufactured in the United States and built to ASTM B16, ASTM B505, ASTM B584, and MSS SP-80 standards

Compatibility

Designed as an OEM-style drop-in replacement or new-installation check valve for 1-1/4 inch FNPT threaded piping systems handling water, steam, oil, or gas service within the stated pressure and temperature ratings.

Installation Notes

Installation is performed by a licensed plumber or pipefitter in accordance with applicable local plumbing codes and IFGC requirements for gas service. Shut off and depressurize the line completely and allow steam or hot-water systems to cool before removing or installing the valve. Apply thread sealant appropriate to the service medium on male threads only, following sealant manufacturer instructions. Do not exceed the rated pressure and temperature limits for the intended media type.

Technical Specifications

• Flow Rate: 54 gpm
• Coefficient of Volume (Cv): 39
• Cracking Pressure: 0.5 psi
• Max. Water Pressure (WOG): 200 psi at 150 degrees F
• Max. Steam Pressure (WSP): 125 psi
• Max. Pressure (SWP): 125 psi
• Max. Temperature: 425 degrees F
• Min. Temperature: -20 degrees F
• Pipe Size: 1-1/4 inches
• Connection Type: FNPT x FNPT
• Mounting Orientation: Horizontal or Vertical
• Overall Length: 4.375 inches
• Overall Height: 3.75 inches
• Width: 1.5 inches
• Cap to Inlet Center: 3 inches
• Body Material: Cast Bronze
• Seat Material: Bronze
• Seal Material: Bronze
• Check Mechanism Material: Brass
• Media: Gas, Oil, Steam, Water
• Standards: ASTM B16, ASTM B505, ASTM B584, MSS SP-80
• Country of Origin: United States

Standard Information

• Brand: MILWAUKEE VALVE
• Manufacturer Part Number: 509y - 114