Sigma 33SP1014C Square Head Pipe Plug 1-1/2 in Mnpt

Product Description

The SIGMA 33SP1014C is a square head pipe plug designed to seal threaded pipe openings in low-pressure piping systems. Constructed from malleable iron with a black finish, this plug features a male NPT (MNPT) end style that threads directly into a female-threaded fitting or pipe end. Rated at 150 lb, it is built for standard-pressure applications in gas, water, and steam distribution lines. Plumbers, pipefitters, and mechanical contractors install this type of plug during pressure testing, system commissioning, or to cap unused branch outlets.

This pipe plug is suited for residential and light commercial piping installations where a 1-1/2 inch MNPT connection is required. Common applications include capping tee branches, closing unused ports on manifolds, and providing temporary or permanent seals during system maintenance. The square head drive allows installation and removal with a wrench without the need for specialized tooling, making it practical for field use.

Key Features

• 1-1/2 inch nominal size with MNPT thread for direct engagement into female-threaded fittings
• 150 lb pressure class rating suitable for standard low-pressure piping systems
• Malleable iron construction provides durability and resistance to mechanical stress
• Black finish for corrosion resistance in typical indoor piping environments
• Square head design accepts standard wrench drive for secure installation and removal

Compatibility

Designed as an OEM-style replacement and standard fitting for 1-1/2 inch female NPT threaded pipe connections in 150 lb class malleable iron piping systems.

Installation Notes

Installation is performed by licensed plumbers or pipefitters in accordance with applicable IPC and IFGC code requirements. Shut off and depressurize the system completely before installing or removing any threaded plugs. Apply an appropriate thread sealant or PTFE tape to the MNPT threads before installation to ensure a leak-free seal. Do not overtighten, as excessive torque can crack malleable iron fittings.

Technical Specifications

• Nominal Size: 1-1/2 inches
• End Style: MNPT (Male National Pipe Thread)
• Pressure Class: 150 lb
• Material: Malleable Iron
• Finish: Black

Standard Information

• Brand: SIGMA
• Manufacturer Part Number: 33SP1014C