We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Cylindrical steel coupling with threaded female ends, matte grey finish

Value Brand

Value Brand Coupling 4" FNPT Steel Class 150

SKU CH-RYD1-81SKW

A steel merchant coupling with 4-inch FNPT threads rated for Class 150 service on Schedule 40 pipe

  • Steel construction resists pressure in Class 150 systems
  • Female NPT threads connect Schedule 40 pipe securely
  • Merchant coupling design simplifies 4 inch pipe joins
  • New condition ensures clean, undamaged threads for sealing
  • California Proposition 65 warning discloses chemical hazards

4-inch Class 150 Steel Coupling

This new ZORO SELECT merchant coupling connects two lengths of 4-inch Schedule 40 pipe using female NPT threads on both ends. The steel body is rated to Class 150 for standard-pressure plumbing and industrial piping systems. It provides a straight, rigid joint for water, air or compatible fluid lines.

Suits 4-inch Schedule 40 NPT systems

Installers joining two male-threaded 4-inch Schedule 40 pipes will find this coupling matches the required thread form and pressure class. It is not intended for pipes of a different nominal size, wall thickness or thread standard. Buyers needing a reducing joint, a different pressure rating or a non-NPT connection must select another fitting.

Female NPT threads on both ends

The defining specification is the dual female NPT thread configuration, which only accepts male NPT pipe ends of the same 4-inch nominal size. This thread form and gender determine whether the coupling can be installed in the existing piping assembly.

Highlights

  • Steel construction resists pressure in Class 150 systems
  • Female NPT threads connect Schedule 40 pipe securely
  • Merchant coupling design simplifies 4 inch pipe joins
  • New condition ensures clean, undamaged threads for sealing
  • California Proposition 65 warning discloses chemical hazards

Specifications

BrandZORO SELECT

Questions about this item

Which pipe schedule must I already have for this 4" FNPT steel Class 150 coupling to thread on correctly?

It is made for Schedule 40 pipe, so the mating pipe must be Schedule 40 for the threads to engage properly.

If I keep my existing 4" NPT fittings, will this coupling thread onto them without adapters?

Yes, both ends are 4" female NPT, so any 4" male NPT component you already own will screw straight in.

After installation, what visual check confirms the coupling is seated and leak-free?

Tighten until the pipe ends meet the internal shoulder, then pressurise the system; no water or air escaping at the joint means it is sealed.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.