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Hexagonal malleable iron locknut with threaded interior and matte dark finish

Value Brand

Value Brand 520-904HC Malleable Iron Hex Locknut Class 150

SKU CH-PC0B-YRSED

A 3/4 inch malleable iron hex locknut rated Class 150 for 300 psi at 150 °F and steam service to 150 psi

  • Malleable iron construction resists cracking under stress
  • Class 150 rating handles 300 psi at 150 °F
  • Hex shape allows secure wrench tightening on pipe threads
  • Meets ANSI B16.39 and ASTM A-197 standards for quality assurance
  • Operates reliably from -20 °F to 366 °F across steam and water systems

ZORO SELECT 520-904HC Hex Locknut

This malleable iron hex locknut is manufactured to Class 150 specifications for pipe fitting applications. It features a 3/4 inch FNPT connection and conforms to Federal Specification WW-P-521, ASTM A-197 material standards, and ANSI B16.39 dimensional standards.

Suitable for standard pressure piping systems

This fitting suits installers needing a Class 150 locknut rated for 300 psi at 150 degrees Fahrenheit and 150 psi saturated steam pressure. It is not for systems requiring higher pressure classes or different connection types beyond the 3/4 inch FNPT specification.

300 psi maximum pressure rating at 150 degrees

The locknut operates across a temperature range of -20 degrees to 366 degrees Fahrenheit. This pressure and temperature envelope determines whether the fitting matches the specific demands of the piping assembly.

Highlights

  • Malleable iron construction resists cracking under stress
  • Class 150 rating handles 300 psi at 150 °F
  • Hex shape allows secure wrench tightening on pipe threads
  • Meets ANSI B16.39 and ASTM A-197 standards for quality assurance
  • Operates reliably from -20 °F to 366 °F across steam and water systems

Specifications

BrandZORO SELECT

Questions about this item

How much heat can the malleable iron hex locknut withstand during continuous operation?

The locknut is rated for a temperature range of -20 to 366 degrees F, with a saturated steam pressure limit of 150 psi at the upper end.

What pipe size and thread type must the existing piping have to accept this locknut?

It requires a 3/4 inch pipe with FNPT threads to match the locknut's connection specification.

Will this Class 150 locknut work with older fittings that follow ANSI B16.39 and ASTM A-197 standards?

Yes, it conforms to ANSI B16.39 and material specification ASTM A-197, matching those legacy standards.

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