Midland Industries LF109SD-4 Square Head Solid Plug 1/4 Mpt

Product Description

The MIDLAND INDUSTRIES LF109SD-4 is a square head solid plug designed to cap off open pipe ends in pressurized plumbing, gas, and fluid-handling systems. Machined from lead-free brass, it threads directly into a female-threaded port using a standard 1/4-18 NPT male thread. The square head profile accepts a wrench for reliable installation torque without slippage. At 0.8 inches in length, this compact plug fits tight spaces without sacrificing thread engagement. Lead-free brass construction meets modern plumbing code requirements for potable water applications. Licensed plumbers and pipefitters are the primary installers.

This plug is suited for residential and light commercial plumbing systems where an open 1/4 in female port needs to be sealed. Typical applications include capping test ports, unused branch connections, and gauge ports on manifolds or distribution systems. The 1/4-18 thread size is common across brass valves, fittings, and manifold blocks used in water supply, compressed air, and low-pressure gas lines. The lead-free brass material makes it appropriate for potable water service where lead-free compliance is required by local code.

Key Features

• Lead-free brass construction meets lead-free plumbing code requirements for potable water systems
• Square head drive accepts standard wrenches for secure, controlled installation
• 1/4-18 male pipe thread (MPT) for direct engagement into standard female NPT ports
• Solid plug design fully seals open pipe ends with no flow path
• Compact 0.8 inch length fits recessed or closely spaced port locations
• Compatible with brass or steel pipe systems

Compatibility

Designed for use with brass or steel pipe systems. Fits any standard 1/4 in female NPT port. Suitable as an OEM-style replacement or service plug in residential and commercial plumbing and fluid-handling assemblies.

Installation Notes

Installation is performed by a licensed plumber or qualified pipefitter. Depressurize and isolate the line before removing or installing any fitting. Apply an appropriate thread sealant or PTFE tape to the male threads per local plumbing code before installation. Do not over-torque brass fittings, as the material is susceptible to cracking under excess force.