Left/Right & Di-Electric Fittings

If you've been searching for those elusive left/right threaded black iron fittings, you've come to the right place. PlumbingSupply.com® is your source for hard-to-find fittings such as these left/right threaded nipple and coupling sets, left/right fittings, dielectric fittings, and many more fittings (PVC, brass, copper and stainless steel), fixtures (sinks, tubs, toilets and faucets), tools and thousands of other plumbing-related products.

Left/Right Nipple And Coupling Set

Shown: 1" x 4" + L/R Coupling Set

These have standard right-hand threads on one side & reverse (left-hand) threads on the other. These are generally used for gas piping, when unions are not allowed.

Description Price & Quantity
1/2" x 4" Nipple + L/R Coupling $12.76
3/4" x 4" Nipple + L/R Coupling $15.25
1" x 4" Nipple + L/R Coupling $22.35
1-1/4" x 4" Nipple + L/R Coupling $27.60
1-1/2" x 4" Nipple + L/R Coupling $36.03
2" x 4" Nipple + L/R Coupling $47.86
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Need to seal your pipe threads? Click here for PTFE tape and pipe dope.

Left / Right Nipple and Coupling Sold Separately

Shown: 1" x 4" Left/Right Nipple
Shown: 1" Left/Right Coupling
L/R Nipples
Size Price & Quantity
1/2" x 4" $3.07
3/4" x 4" $3.66
1" x 4" $5.11
1-1/4" x 4" $7.29
1-1/2" x 4" $8.56
2" x 4" $11.41
Note: You need both a left/right nipple & a left/right coupling to use these
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L/R Couplings
Size Price & Quantity
1/2" $11.11
3/4" $13.27
1" $19.73
1-1/4" $23.38
1-1/2" $31.47
2" $41.76
Note: You need both a left/right nipple & a left/right coupling to use these
- OR - View Cart
Need to seal your pipe threads? Click here for PTFE tape and pipe dope.

Di-Electric Unions - Forged Steel
Sweat x Fips

Di-Electric Unions help stop corrosion of the galvanized piping when transitioning to copper pipe.
Shown: 3" Sweat x Fips Di-Electric Forged Steel Union - Flanged Style
Shown: 1" Sweat x Fips Di-Electric Forged Steel Union
Not for potable/drinking water
can use for hydronic heating, irrigation, air lines, etc.
Fitting Size Price & Quantity
1/2" $3.79
2" $19.31
3" - flanged style $147.63
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For Potable/Drinking Water
Fitting Size Price & Quantity
1/2" $6.36
3/4" $6.56
1" $9.14
1-1/4" $14.41
1-1/2" $24.21
2" $33.84
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Looking for copper unions?

Di-Electric Unions - Galvanized
Fips x Fips

Shown: 1" Fips x Fips Di-Electric Galvanized Union
Fitting Size Price & Quantity
1/2" $7.88
3/4" $8.14
1" $12.68
1-1/4" $23.30
1-1/2" $30.24
2" $34.86
- OR - View Cart

Need to seal your pipe threads? Click here for PTFE tape and pipe dope.

Insulated Di-Electric Couplings - Galvanized
Fips x Fips

Galvanized steel body internally insulated with ABS plastic

Maximum working temperature 180°F

Shown: 3/4" Fips x Fips Insulated Di-Electric Galvanized Coupling
Fitting Size Price & Quantity
1/2" $16.12
3/4" $17.58
1" $19.52
1-1/4" $28.02
1-1/2" $40.37
2" $47.44
- OR - View Cart

Need to seal your pipe threads? See below.

Click here for stainless water heater flexes - they act as dielectric fittings as well.

Thread Sealants (IPS Threads)

Product Description Price & Quantity
PTFE thread sealing tape
  • 3.5 Mil thick
  • Density: 0.4
 1/2" x 260" roll $0.72
1/2" x 520" roll $1.03 Enter a quantity and
GRAY PTFE thread sealing tape
  • 4 Mil THICK
  • Density: 1.2
  • 1/2" x 260" roll
  • Proudly made in the USA
$2.66 Enter a quantity and
1 oz. Great White™ Basic Pipe Joint Compound
  • Small, convenient tube
  • Great for most plastics and metals
 $3.35 Enter a quantity and
4 oz. High Quality TU-555 Pipe Joint Compound
  • Available in larger sizes, too
  • Great for most plastics and metals
Order 12, 24 or 48 of this item for additional savings!
Pricing discounts will show up in your shopping cart. 		$8.14 Enter a quantity and

To ensure our customers receive fresh products, TU-555 pipe joint compounds are non-returnable.

Related Items & Accessories

Brass Nipples Brass Compression Fittings Flare Fittings Gas Valves Commercial Gas Connectors Testing Kits How to Measure Pipe Size Portable Pipe Threaders
Frequently Asked Questions

Q. "Any left- and right-hand tricks?"
A. The trick for left- and right-hand fittings and couplings is to get the correct bite the first time. The way to do that is to insert one side of the nipple/coupling and hand-tighten. Count the number of turns to get it to hand-tight. Then take apart and do the same on the other side. If one side took more turns to get it to hand-tighten, then add (or subtract) that number before starting; and turn that amount into the side that took more turns. In other words, the secret is to tighten the same amount after hand-tightening.

Q. "I want to attach galvanized piping to copper piping, but my friend said I need a dielectric union. Is this correct?"
A. Yes, some type of isolation must be placed between galvanized steel pipe and copper piping. Many plumbers use dielectric unions or insulated couplings for this purpose. Dissimilar metals, ferrous and non-ferrous, joined together will cause one of the metals to corrode. Usually in piping applications the ferrous metal will corrode, in this case the galvanized. Ferrous metals have iron in them, and non-ferrous metals do not. When galvanized is attached to copper the galvanized is electro-negative and the copper is electro-positive which causes the galvanized to corrode, also known as galvanic corrosion. Water heaters also need some type of dielectric connection from the steel tank if copper pipe is being used. Stainless steel water flexes work well as a dielectric isolation between the steel tank and the copper piping.

Q. "I'm hearing a lot about lead-free these days. What does that have to do with plumbing products and how does the new lead-free legislation affect me?"
A. Basically, the laws implemented Jan. 1st, 2014 require plumbing products that come in contact with drinking water to be "essentially lead free" (less than 0.25% weighted average). For further information about how the law determines what is "lead free", rules regarding which plumbing products must be "lead free", and who these laws will affect, please click here.

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