Watts 821787 Lead Free Black Dielectric Union 3/4 Inch

Product Description

The WATTS 821787 is a 3/4-inch IPS lead free black dielectric union designed to prevent accelerated corrosion and deterioration in piping systems caused by galvanic action and stray electrical current. It connects pipes made from dissimilar metals by isolating them electrically, using a Buna-N gasket between two tailpieces to break the current path. The assembly includes a union nut, two tailpieces, and female iron pipe thread to female iron pipe thread connections finished in black. Rated to 180 degrees F and 250 psi, this union is built for demanding residential and commercial service conditions. Licensed plumbers install this fitting as part of code-compliant piping assemblies.

This dielectric union is used in both residential and commercial plumbing installations where copper and steel piping meet. Common applications include hot water storage tanks, water heaters, air conditioning systems, processing tanks, steam piping, gas piping, and potable water piping. The lead free construction makes it suitable for use in systems carrying drinking water where lead-free compliance is required by local plumbing codes.

Key Features

• Lead free construction for compliance with drinking water regulations
• Buna-N gasket electrically isolates tailpieces to stop galvanic current flow
• Female iron pipe thread to female iron pipe thread connections in black finish
• Rated to 250 psi maximum working pressure
• Maximum temperature rating of 180 degrees F (82 degrees C)
• Suitable for steam, gas, water, and hot water storage tank applications

Compatibility

Designed as an OEM-style replacement dielectric union for residential and commercial plumbing systems where dissimilar metal pipe connections require galvanic isolation, including hot water storage tanks, water and air conditioning systems, processing tanks, and steam, gas, and water piping.

Installation Notes

Installation should be performed by a licensed plumber in accordance with applicable local plumbing codes. Shut off the water supply and relieve system pressure before beginning any pipe work. Use appropriate thread sealant or PTFE tape on the FIP threads and avoid over-tightening, which can damage the gasket seat. Verify that the Buna-N gasket is properly seated before final assembly to ensure electrical isolation is maintained.

Technical Specifications

• Pipe Size: 3/4 inch IPS
• Connection Type: Female Iron Pipe Thread (FIP) x Female Iron Pipe Thread (FIP)
• Finish: Black
• Gasket Material: Buna-N
• Maximum Working Pressure: 250 psi (17.2 bar)
• Maximum Temperature: 180 degrees F (82 degrees C)
• Lead Free: Yes

Standard Information

• Brand: WATTS
• Manufacturer Part Number: 821787