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
Small silver stainless steel pipe union with hex nut and female threads

Zoro Select

Zoro Select 400U111N014 1/4 in FNPT 304 Stainless Steel Union Class 150 300 psi equipment

SKU CH-5CBB-QD5KY

A 1/4-inch FNPT stainless-steel union rated to 300 psi for air, gas, water, oil and steam service

  • 304 stainless steel resists corrosion across air, gas, water, oil and steam systems
  • Three-piece union design allows pipe connection or disconnection without rotating the piping
  • Female NPT threads on both ends with 18 threads per inch ensure secure sealing
  • Class 150 rating supports 300 psi working pressure and 150 psi steam pressure
  • Meets ASTM A351, ANSI/ASME B1.20.1 and MSS-SP-114 standards for reliable performance

1/4 in FNPT 304 Stainless Steel Union

This Zoro Select pipe union joins two pipe ends using internal female NPT threads of 1/4 inch nominal size on both sides. It is constructed from 304 stainless steel with a three-piece design comprising a body, nut, and mating seat. The silver fitting allows connection or disconnection without rotating the pipes.

Upgrade from threaded couplings

Unlike a standard coupling, this union enables disassembly for maintenance or replacement without turning the connected piping. The jump is worth it when system layout prevents pipe rotation or when frequent access to joints is required for inspection, cleaning, or component swaps in air, gas, water, oil, or steam lines.

Class 150 pressure limits

The fitting conforms to MSS-SP-114 Class 150 ratings with a maximum operating pressure of 300 psi for non-steam service and 150 psi for steam. It is compatible with Schedule 40 pipe and meets ASTM A351 and ANSI/ASME B1.20.1 standards. The 30.5 mm hex flats provide the wrench interface for assembly.

Highlights

  • 304 stainless steel resists corrosion across air, gas, water, oil and steam systems
  • Three-piece union design allows pipe connection or disconnection without rotating the piping
  • Female NPT threads on both ends with 18 threads per inch ensure secure sealing
  • Class 150 rating supports 300 psi working pressure and 150 psi steam pressure
  • Meets ASTM A351, ANSI/ASME B1.20.1 and MSS-SP-114 standards for reliable performance

Specifications

BrandZORO SELECT

Questions about this item

What size wrench fits the 30.5 mm hex on this 1/4 inch FNPT union?

Use a 30.5 mm wrench across the flats to tighten the nut without damaging the 304 stainless steel body.

How do I install the three-piece union without twisting the connected pipes?

Thread each 1/4 inch FNPT end onto the pipe, then tighten the central nut to draw the seat and gasket together — no pipe rotation needed.

When should I replace the seat or gasket inside this Class 150 stainless steel union?

Replace the mating seat or gasket if leaks appear at the joint or during scheduled maintenance on air, gas, water, oil or steam lines up to 300 psi.

Also in this aisle

People compared these

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