Trade Grade 1/2 Inch GI Union, Female BSP Threaded, Galvanized Iron

1/2 Inch GI Union

The Trade Grade GI Union provides a high-pressure, disconnectable joint for 1/2 inch galvanized steel piping systems. This three-piece fitting allows contractors to break and reconnect pipe runs without rotating the entire pipe length. It features heavy-duty cast iron construction with a hot-dip zinc coating to resist corrosion in residential and industrial plumbing applications.

Built for the Job

Plumbers and site supervisors specify this fitting for locations requiring frequent equipment maintenance. In a rigid piping system, removing a pump, valve, or meter is impossible without a union. This hardware component consists of two threaded end pieces and a large central nut that draws them together against a precision-machined ground joint. The design ensures a metal-to-metal seal that handles thermal expansion and contraction better than standard couplings. It is frequently used in pump house installations, water meter assemblies, and overhead fire protection lines where structural integrity is paramount.

• Connecting water pumps and pressure tanks for easy removal during service.

• Installing inline valves and filters in commercial water distribution networks.

• Repairing damaged sections of 15mm galvanized pipe in existing structures.

Product Highlights

Corrosion Protection

The hot-dip galvanizing process creates a thick zinc layer that protects the base metal from oxidation in damp environments.

Mechanical Integrity

• Class 150 pressure rating suitable for standard municipal water systems.
• Precision-cut BSP threads ensure compatibility with all standard 1/2″ iron pipe fittings.

Technical Specifications

What’s Included

• 1 x 1/2 Inch Galvanized Iron 3-Piece Union

On-Site & Workshop Notes

• Apply PTFE thread tape or an approved pipe joint compound to the male threads before mating with this fitting.

• Clean the internal seating surfaces of the ground joint to ensure a leak-proof seal without requiring excessive torque.

• Use two 12-inch pipe wrenches during installation—one to stabilize the pipe and the other to tighten the union nut.

• Store in a dry area to maintain the integrity of the zinc coating before site installation.