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
Straight copper coupling, smooth metallic finish, 3/4 inch sweat fitting

Nibco, Inc.

Nibco, Inc. 621 3/4 in Straight Copper Coupling

SKU CH-FDDC-XYC4S

Straight copper sweat adapter joins two 3/4 in tubes for air, gas or potable water up to 466 psi at 200 °F

  • Straight adapter joins two 3/4 in copper tubes
  • Wrot copper construction resists corrosion in potable water systems
  • Rated for 466 psi at 200 Degrees F operating pressure
  • Withstands temperatures up to 400 Degrees F in hot water lines
  • Sweat fitting design creates permanent leak-free joints

Straight Copper Sweat Adapter

The NIBCO 621 is a straight sweat fitting adapter made from wrot copper. It joins two 3/4 in copper tubes with FTG connections on both ends. The fitting handles air, gases and potable water in residential and commercial plumbing systems. It is supplied new and ready for installation.

Suits standard copper pipe joins

This coupling suits installers who need a straight, solder-type joint between equal-size copper tubes. It is not for threaded, press-fit or push-fit connections. It does not adapt between different tube diameters or materials. Buyers who need a reducing coupling, a threaded adapter or a fitting for plastic pipe should look at something else.

Pressure and temperature headroom

The fitting withstands a maximum operating pressure of 466 psi at 200 Degrees F and a maximum operating temperature of 400 Degrees F. These ratings cover typical hot and cold water distribution and low-pressure gas lines. Systems that exceed either limit will require a fitting rated for higher pressure or temperature.

Highlights

  • Straight adapter joins two 3/4 in copper tubes
  • Wrot copper construction resists corrosion in potable water systems
  • Rated for 466 psi at 200 Degrees F operating pressure
  • Withstands temperatures up to 400 Degrees F in hot water lines
  • Sweat fitting design creates permanent leak-free joints

Specifications

BrandNIBCO

Questions about this item

What copper tube size must the existing pipe be for the 3/4 in FTG ends to fit?

The fitting accepts 3/4 in copper tube on both ends, matching a 7/8 in outer diameter.

Will the 466 psi rating at 200 °F handle the same pressures as older copper lines?

Rated to 466 psi at 200 °F and 400 °F maximum temperature, it meets or exceeds typical residential copper system limits.

How can I confirm the sweat joint is sound after soldering?

Pressurise the line to its working pressure and inspect each joint for leaks; a tight joint shows no seepage at 466 psi.

Also in this aisle

People compared these

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