Bk Mueller 511-803HN 1/2 Inch Malleable Iron Square Plug

Product Description

The BK MUELLER 511-803HN is a malleable iron square plug fitting designed to seal off pipe ends in threaded piping systems. Sized at 1/2 inch with a standard threaded end connection, it carries a pressure rating of 300 psi for liquid and gas service and 150 psi for steam. The galvanized finish provides corrosion resistance in exposed or mildly corrosive environments. This fitting is a Class 150 component and is installed by licensed plumbers and pipefitters working on gas distribution, water, and low-pressure steam systems.

This square plug is suited for residential and light commercial piping applications where a threaded pipe end must be capped or temporarily closed. Common uses include capping unused branch outlets on gas lines, water supply headers, and compressed air distribution piping. The 1/2 inch threaded connection meets standard NPT fitting dimensions, making it compatible with a wide range of iron and steel pipe assemblies encountered in plumbing, HVAC, and industrial service work.

Key Features

• Malleable iron construction provides strength and impact resistance suitable for threaded piping systems
• Galvanized finish for corrosion protection in exposed installations
• 300 psi liquid and gas pressure rating for reliable service in pressurized lines
• 150 psi steam pressure rating for low-pressure steam applications
• Class 150 fitting designation consistent with standard pipe fitting specifications
• Square head drive allows engagement with a pipe wrench or adjustable wrench for secure installation

Compatibility

Designed as an OEM-style replacement and standard-service fitting for 1/2 inch threaded iron and steel pipe assemblies in plumbing, gas, and low-pressure steam systems.

Installation Notes

Installation should be performed by a licensed plumber or pipefitter in accordance with applicable local plumbing codes and IFGC requirements. Depressurize and isolate the line before installing or removing any threaded pipe fitting. Apply an appropriate thread sealant or PTFE tape to the male threads before assembly. Do not overtighten; use a wrench on the square head and follow standard pipe fitting torque practices for the pipe material and size.