Sigma 812509008 Ground Joint Union 1-1/2 in Fnpt 150 Lb

Product Description

The SIGMA 812509008 is a ground joint pipe union sized at 1-1/2 inches nominal with female NPT (FNPT) end connections and a 150 lb pressure rating. Constructed from black malleable iron, this union allows sections of threaded pipe to be disconnected and reconnected without rotating the pipe itself. The ground joint seat provides a metal-to-metal seal that holds up in higher-vibration or higher-temperature service conditions. It is a standard fitting used by plumbers and pipefitters working on gas distribution, steam, and general industrial piping systems.

This union is suited for residential and commercial piping applications where routine disconnection of pipe runs is required for maintenance or equipment service. Typical installations include gas supply lines, compressed air distribution, steam lines, and industrial process piping. The 150 lb class rating makes it appropriate for low-pressure service piping governed by standard threaded fitting specifications. The black finish is standard for gas and steam piping applications.

Key Features

• 1-1/2 inch nominal size with FNPT threaded connections on both ends
• 150 lb pressure class rating for low-pressure piping service
• Ground joint metal-to-metal seat for a secure, leak-resistant connection
• Malleable iron construction for strength and resistance to impact and vibration
• Black finish standard for gas and steam piping applications
• Allows pipe disconnection without rotating the mating pipe sections

Compatibility

Designed as an OEM-style replacement fitting for standard 1-1/2 inch FNPT threaded pipe systems rated at 150 lb class, including gas, steam, and compressed air distribution piping.

Installation Notes

Installation is performed by licensed plumbers or pipefitters. Shut off and depressurize the system completely before removing or installing any union fitting. Apply thread sealant or PTFE tape rated for the service medium to all threaded connections in accordance with local code requirements, including IFGC provisions for gas piping. Do not overtighten the union nut — hand-snug plus wrench turns per standard practice is sufficient to seat the ground joint without damaging the sealing faces.

Technical Specifications

• Nominal Size: 1-1/2 inches
• End Style: FNPT (Female National Pipe Thread)
• Pressure Rating: 150 lb
• Material: Malleable Iron
• Finish: Black
• Joint Type: Ground Joint

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 812509008