B K/mueller Inds(import) 521-707HN Black Union 1-1/2 in

Product Description

The B K/MUELLER INDS(IMPORT) 521-707HN is a 1-1/2 inch black union constructed from brass and iron. Unions allow piping sections to be disconnected and reconnected without cutting or threading existing pipe runs, making them a routine component in gas, water, and hydronic systems. This unit ships in a package of four, suited for contractors stocking commonly used fittings. The brass-and-iron construction provides corrosion resistance at the seating surfaces while maintaining the strength required for black iron piping applications. Plumbers and pipefitters use this fitting where future serviceability of a piping connection is required.

This union is sized at 1-1/2 inches and is designed for use in black iron pipe systems commonly found in residential and light commercial gas distribution, steam heating, and hydronic heating installations. It is appropriate for applications where a mechanical disconnect point is needed in the line. The package quantity of four makes it practical for multi-zone or multi-appliance installations where several union points are required in a single job.

Key Features

• 1-1/2 inch pipe size for standard black iron pipe connections
• Brass and iron construction for durable, corrosion-resistant seating
• Union design allows pipe disconnection without cutting or rethreading
• Sold in a package of four units per order
• Suitable for gas, steam, and hydronic piping systems

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 1-1/2 inch black iron pipe systems in residential and light commercial applications.

Installation Notes

Installation is performed by licensed plumbers or pipefitters following applicable local codes and IFGC or IPC requirements. Shut off and isolate the line and verify zero pressure before disassembling or installing any union fitting. Use appropriate thread sealant rated for the service medium — gas-rated compound for gas lines, PTFE tape or pipe dope for water and steam. Hand-tighten the union nut before applying wrench torque to avoid cross-threading the brass seat.