A.y. Mcdonald 5421-107 Swing Check Valve 1-1/4 in Sweat

Product Description

The A.Y. MCDONALD 5421-107 is a 1-1/4 inch sweat-connection swing check valve rated for 125 PSI service. It allows flow in one direction and closes automatically to prevent backflow when flow stops or reverses. The swing-type disc design provides low pressure drop during normal flow conditions. This valve is installed by licensed plumbers and HVAC-R technicians in water supply, heating, and general fluid-handling systems where backflow prevention is required at the line level.

This valve is suited for residential and light commercial plumbing and hydronic heating applications. The sweat-end connections are compatible with standard copper tubing, making it a straightforward drop-in for new installations or service replacements in closed-loop and open water systems. At 1-1/4 inches, it fits branch and main-line configurations commonly found in baseboard heating loops, domestic water mains, and pump discharge lines.

Key Features

• Swing-disc design provides automatic backflow prevention without external actuation
• 1-1/4 inch sweat (copper solder) end connections for standard copper tubing
• 125 PSI pressure class suitable for residential and light commercial service
• Compact body weight of 1.14 pounds keeps installation practical in tight spaces
• Passive operation with no power source or actuator required

Compatibility

Designed as an OEM-style replacement or new-installation swing check valve for 1-1/4 inch copper sweat piping systems in residential and light commercial plumbing and hydronic heating applications.

Installation Notes

Installation should be performed by a licensed plumber in accordance with applicable local plumbing codes and the IPC. Shut off the water supply and depressurize the line before soldering. Observe the flow-direction arrow cast or stamped on the valve body and orient the valve accordingly during installation. Allow the valve body to cool fully after soldering before restoring system pressure to avoid heat damage to internal components.

Technical Specifications

• Connection Type: Sweat
• Size: 1-1/4 inches
• Valve Type: Swing Check
• Pressure Class: 125 psi
• Weight: 1.14 pounds

Standard Information

• Brand: A.Y. MCDONALD
• Manufacturer Part Number: 5421-107