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Malleable iron reducer coupling, dark grey finish, threaded ends, 3/4 by 3/8 inch

Value Brand

Value Brand 3/4" x 3/8" Malleable Iron Reducer Coupling

SKU CH-N798-HK16K

Malleable iron reducer coupling connects 3/4 inch and 3/8 inch FNPT pipes, rated 300 psi at 150 degrees F with FM and UL listings

  • Connects 3/4 in to 3/8 in pipe with FNPT threads
  • Malleable iron construction meets ASME B16.3 and B16.4 standards
  • Rated 300 psi at 150 °F for water, oil or air lines
  • FM Approved and UL Listed for fire-protection and general service
  • Operates from -20 °F to 366 °F for steam and hot-water systems

3/4" x 3/8" Malleable Iron Reducer

This reducer coupling connects 3/4 inch and 3/8 inch female NPT threads. The malleable iron body meets Class 150 specifications for standard plumbing installations. It is built to ASME B 16.3 and B 16.4 standards for reliable performance.

Suits plumbers joining dissimilar pipe sizes

Installers needing a straight coupling or a different thread standard should choose another fitting. This part only reduces between the two stated NPT sizes. Systems requiring pressures above 300 psi at 150°F must use a higher-rated component.

Class 150 with 300 psi maximum pressure

The fitting handles up to 300 psi at 150 degrees Fahrenheit and 150 psi saturated steam. Operating temperatures range from -20 to 366 degrees Fahrenheit. It carries FM Approved and UL Listed certifications for safety compliance.

Highlights

  • Connects 3/4 in to 3/8 in pipe with FNPT threads
  • Malleable iron construction meets ASME B16.3 and B16.4 standards
  • Rated 300 psi at 150 °F for water, oil or air lines
  • FM Approved and UL Listed for fire-protection and general service
  • Operates from -20 °F to 366 °F for steam and hot-water systems

Specifications

BrandZORO SELECT

Questions about this item

How do I install the 3/4" x 3/8" FNPT reducer coupling and what step is often missed?

Wrap PTFE tape or apply pipe dope on the male threads, then tighten both FNPT ends with two wrenches to avoid cracking the malleable iron. The step people miss is using two wrenches — one on the fitting, one on the pipe — so the coupling does not twist and stress the threads.

What maintenance or replacement will this Class 150 malleable iron coupling need over time?

Inspect the joint annually for corrosion, mineral buildup, or slow leaks. Replace the coupling if threads show galling, the body cracks, or the seal weeps after re-taping. The ASTM A197 iron resists wear, but thermal cycling between -20 °F and 366 °F can eventually fatigue the material.

What is the first pressure or temperature limit reached under continuous saturated-steam service?

The saturated-steam rating of 150 psi is reached well before the 300 psi water-pressure rating at 150 °F, so steam pressure is the governing limit for sustained steam use.

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