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Small square-head pipe plug, dark iron finish, 1/8 inch MNPT

Value Brand

Value Brand Square Head Plug 1/8" MNPT Malleable 150 540

SKU CH-HDZ3-8JH4B

Square-head malleable-iron pipe plug with 1/8-inch male NPT threads rated to 150 psi and -20 to 366 °F

  • Square head allows easy wrench tightening on 1/8" MNPT threads
  • Malleable iron construction rated Class 150 for durable plumbing connections
  • Operates from -20°F to 366°F across heating and cooling systems
  • Cored plug design reduces weight while maintaining structural integrity
  • Complies with California Proposition 65 chemical disclosure requirements

Square Head Plug 1/8" MNPT

The Value Brand square head plug is a malleable iron fitting rated for Class 150 service. It connects to 1/8 inch nominal pipe threads in plumbing or compressed-air systems. Installers use it to seal unused ports during assembly or maintenance.

Temperature range -20 to 366 °F

The malleable iron body handles continuous operating temperatures from minus 20 up to 366 degrees Fahrenheit. No pre-applied thread sealant is included, so the joint remains free of sealant residue that could affect fluid purity.

Class 150 malleable iron construction

The cored plug design reduces weight while maintaining the pressure rating for standard Class 150 piping. Male NPT threads allow direct engagement with female-threaded fittings, valves or equipment ports without additional adapters.

Highlights

  • Square head allows easy wrench tightening on 1/8" MNPT threads
  • Malleable iron construction rated Class 150 for durable plumbing connections
  • Operates from -20°F to 366°F across heating and cooling systems
  • Cored plug design reduces weight while maintaining structural integrity
  • Complies with California Proposition 65 chemical disclosure requirements

Specifications

BrandZORO SELECT

Questions about this item

How do I install the 1/8" MNPT square head plug without damaging the threads?

Apply PTFE tape or pipe dope to the male NPT threads, then tighten the square head with a wrench until the joint is snug and leak-free; avoid over-torquing the malleable iron body.

Will the pre-applied thread sealant need replacement after repeated disassembly?

The plug ships without pre-applied sealant, so fresh PTFE tape or pipe dope must be applied each time the fitting is reassembled to maintain a reliable seal.

At what temperature does the Class 150 malleable iron plug reach its pressure limit during sustained hot-water service?

The fitting is rated from -20 °F to 366 °F; at the upper end of this range the Class 150 pressure rating becomes the limiting factor for continuous operation.

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