Sigma 818907412 Hex Head Pipe Bushing 1.5x1.25 in Mnpt Fnpt

Product Description

The SIGMA 818907412 is a FIG 3383 hex head pipe bushing designed to reduce a 1-1/2 inch male NPT connection down to a 1-1/4 inch female NPT port. Constructed from malleable iron with a black oxide finish, this bushing is built for use in low-pressure piping systems where a durable, threaded reduction fitting is required. The hex head profile allows for wrench engagement during installation, making tightening and removal straightforward. At a 150 lb pressure rating, it suits standard residential and light commercial piping applications. Licensed plumbers and pipefitters are the typical installers for this class of fitting.

This bushing fits into pipe systems that require a step-down reduction between nominal 1-1/2 inch and 1-1/4 inch threaded pipe. It is commonly used in hydronic heating systems, gas distribution piping, compressed air lines, and general plumbing rough-in work. The MNPT x FNPT configuration means the male thread screws into a larger female-threaded fitting or valve, while the female end accepts a smaller male-threaded pipe or nipple. This fitting is suited for both residential and light commercial installations where malleable iron fittings meet system specifications.

Key Features

• Hex head design allows wrench engagement for secure make-up and removal
• Malleable iron construction provides strength and impact resistance in threaded piping systems
• Black oxide finish offers surface protection in dry or low-moisture environments
• 150 lb pressure class suits standard residential and light commercial service
• MNPT x FNPT end style for direct threaded connections without additional adapters
• Nominal 1-1/2 x 1-1/4 inch sizing covers a common reduction step in pipe assemblies

Compatibility

Designed as an OEM-style threaded reduction fitting for use in standard 150 lb malleable iron pipe systems with NPT threaded connections.

Installation Notes

Installation is performed by a licensed plumber or pipefitter following applicable IPC or IFGC requirements for the system type. Shut off and depressurize the piping system fully before removing or installing any threaded fitting. Apply an appropriate thread sealant or PTFE tape to the male threads before make-up. Do not overtighten malleable iron fittings, as the material can crack under excessive torque.

Technical Specifications

• Figure Number: FIG 3383
• Nominal Size: 1-1/2 x 1-1/4 inches
• End Style: MNPT x FNPT
• Pressure Rating: 150 lb
• Material: Malleable Iron
• Finish: Black Oxide

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 818907412