Sigma 812508810 Ground Joint Pipe Union 1-1/4 in Fnpt 150 Lb

Product Description

The SIGMA 812508810 is a FIG 3463 ground joint pipe union designed for threaded pipe assemblies in gas, steam, and water piping systems. It features female national pipe taper (FNPT) end connections on both sides and a ground metal-to-metal seating surface that provides a tight, leak-resistant joint without relying solely on thread engagement. Rated at 150 lb, the union is constructed from black malleable iron, which offers the ductility and impact resistance required in mechanical rooms and utility installations. Licensed plumbers and pipefitters typically install this fitting as part of service disconnects in commercial and residential piping runs.

This union is suited for 1-1/4 inch nominal pipe installations where a serviceable break point is needed in the line. Common applications include boiler piping, gas distribution headers, steam heating systems, and general industrial plumbing where code requires a union fitting to allow equipment removal without cutting pipe. The FNPT thread pattern conforms to standard ANSI pipe thread sizing, making this fitting compatible with standard Schedule 40 and Schedule 80 iron or steel pipe of the same nominal size.

Key Features

• Ground metal-to-metal joint seat provides a secure, leak-resistant seal at the union face
• 1-1/4 inch nominal size with FNPT connections on both ends
• 150 lb pressure class rating suitable for steam, gas, and water service
• Black malleable iron construction resists cracking and deformation under mechanical stress
• Standard ANSI FNPT threading ensures compatibility with common iron and steel pipe

Compatibility

Designed as an OEM-style replacement and standard service fitting for 1-1/4 inch nominal FNPT threaded iron or steel pipe systems rated at 150 lb class.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with the International Plumbing Code (IPC) or International Fuel Gas Code (IFGC) as applicable to the service. Shut off and depressurize the piping system fully before disassembling or installing the union. Apply appropriate thread sealant or PTFE tape to the FNPT threads before assembly; do not use thread sealant on the ground joint seating face. Tighten the union nut with a pipe wrench to achieve a firm, snug fit and verify with a pressure test before returning the system to service.

Technical Specifications

• Nominal Pipe Size: 1-1/4 inches
• End Style: FNPT (Female National Pipe Taper)
• Pressure Class: 150 lb
• Material: Malleable Iron
• Finish: Black
• Figure Number: FIG 3463

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 812508810