Sigma 811031608 Fig 3105 Straight Pipe Tee 4 in Fnpt 150 Lb

Product Description

The SIGMA 811031608 is a FIG 3105 straight pipe tee designed for threaded piping systems in commercial and industrial plumbing, fire protection, and mechanical applications. Built from malleable iron with a galvanized finish, this tee provides a 4-inch nominal pipe size connection with female national pipe thread (FNPT) end style on all three ports. Rated at 150 lb, it handles the pressures common in standard water, air, and compatible fluid distribution systems. Licensed plumbers and pipefitters install this fitting as part of threaded iron pipe assemblies where durability and corrosion resistance are priorities.

This straight tee is suited for residential and commercial piping runs where a branch connection is required at a 90-degree angle to the main line. Typical applications include water distribution, compressed air lines, fire sprinkler systems, and general mechanical piping. The galvanized coating adds resistance to rust and corrosion, making it appropriate for exposed or damp environments. It conforms to the FIG 3105 standard for malleable iron threaded fittings.

Key Features

• 4-inch nominal pipe size for use in full-bore straight tee configurations
• FNPT end style on all three ports for standard threaded iron pipe assembly
• 150 lb pressure rating suitable for water, air, and general fluid service
• Malleable iron construction provides strength and impact resistance
• Galvanized finish resists corrosion in wet or exposed installations
• FIG 3105 designation for easy cross-reference and replacement sourcing

Compatibility

Designed as an OEM-style replacement fitting for standard 4-inch threaded malleable iron piping systems using 150 lb fittings per ASME B16.3 practices.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter following applicable IPC or local mechanical code requirements. Shut off and depressurize the piping system completely before removing or installing any threaded fitting. Apply an approved pipe thread sealant or PTFE tape to all male threads before assembly. Do not over-tighten, as malleable iron fittings can crack under excessive torque.

Technical Specifications

• Nominal Pipe Size: 4 inches
• End Style: FNPT (Female National Pipe Thread)
• Pressure Rating: 150 lb
• Material: Malleable Iron
• Finish: Galvanized
• Figure Number: FIG 3105
• Configuration: Straight Tee

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 811031608