Sigma 34U 1040C Pipe Union 4 Inch Fnpt 150 Lb Galvanized

Product Description

The SIGMA 34U 1040C is a malleable iron pipe union with a brass seat, designed for threaded piping systems in plumbing, HVAC, and industrial piping applications. At 4 inches nominal size with female NPT (FNPT) end connections, this union allows pipelines to be disconnected and reconnected without rotating adjacent pipe sections. The galvanized finish provides corrosion resistance for use in moderate-exposure environments. Rated at 150 lb pressure class, it is a standard fitting for low-pressure gas, water, and steam distribution systems. Installation is typically handled by licensed plumbers or pipefitters working on commercial or industrial piping runs.

This union fits into threaded malleable iron piping systems at 4 inches nominal pipe size. Its 150 lb class rating makes it appropriate for residential and light commercial water supply, low-pressure steam, and gas distribution piping where a break-apart connection point is required for serviceability. The FNPT end style is compatible with standard NPT-threaded pipe and fittings. Galvanized finish suits above-ground and exposed indoor installations where moisture contact is a factor.

Key Features

• 4 inch nominal size with FNPT end connections for standard NPT threaded pipe
• Brass seat provides a leak-resistant metal-to-metal sealing surface at the union joint
• Malleable iron body offers strength and durability in threaded piping assemblies
• Galvanized finish adds corrosion resistance for exposed or damp indoor environments
• 150 lb pressure class suits low-pressure water, gas, and steam service

Compatibility

Designed as an OEM-style replacement or new-installation fitting for 4 inch nominal NPT threaded malleable iron piping systems rated at 150 lb pressure class.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable local codes and the International Plumbing Code (IPC) or International Fuel Gas Code (IFGC) as relevant to the service. Shut off and depressurize the line completely before disassembling or installing any union fitting. Apply an appropriate thread sealant or PTFE tape to the NPT threads before assembly. Do not over-tighten the union nut, as this can damage the brass seat and compromise the seal.

Technical Specifications

• Nominal Size: 4 inches
• End Style: FNPT (Female National Pipe Thread)
• Pressure Rating: 150 lb
• Body Material: Malleable Iron
• Seat Material: Brass
• Finish: Galvanized

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 34U 1040C