WATTS Dielectric Unions

Used with water heaters for separating two metal pipes of different materials and to prevent galvanic corrosion. Available in different connection types

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Watts dielectric unions provide insulation between two different materials to prevent electrolysis which may lead to corrosion or pipe failure. Series LF3100 unions feature a female iron pipe...Read more
WATTS -

Insulator Kits

StyleModelMfr. SeriesPrice (inc. VAT)
AINK-A-KITRK-3000£5.94
BINS-KIT 1/2RK-3100/3110/3200£8.17
WATTS -

LF3100 Series, Dielectric Flange, FIP x Solder

StyleModelBody MaterialMax. PressurePipe SizePrice (inc. VAT)
A3 LF3100Copper and Iron175 psi3"£448.19
B2 1/2 LF3100Copper and Iron175 psi2.5"£354.92
C2 LF 3100 2"Malleable Iron and Brass250 psi2"£329.34
StyleModelHex SizePipe SizePrice (inc. VAT)
A1/2 LF 3005-1/2A1.5"1/2"£16.70
A3/4 LF 3005-3/4A1.625"3/4"£20.85
WATTS -

LF3110 Series, Dielectric Flange, Solder

StyleModelPipe SizePrice (inc. VAT)
A2 1/2 LF31102.5"£597.43
B3 LF31103"£579.35
C4 LF31104"£669.96
StyleModelPipe SizePrice (inc. VAT)
A3200 22"£259.58
A3200 21/2"2.5"£285.24
A3200 3"3"£332.51
A3200 4"4"£508.51
WATTS -

LF3008 Series Dielectric Unions

StyleModelGasket MaterialHex SizeInlet SizeOutlet SizePipe SizePrice (inc. VAT)
ALF3008 3/4Buna-N-3/4"3/4"-£57.19
B3/4 LF3008Buna-N1.625"--3/4"£52.78
B1/2 LF3008Buna-N1.5"--1/2"£44.77
C1 LF3008Buna-N1.875"--1"£60.28
ALF3008 1/2Buna-N-1/2"1/2"-£55.16
DLF3008 1Buna N-1"1"-£98.27
WATTS -

LF3003 Series Dielectric Unions

Watts LF3003 Series dielectric unions are installed at the junction of pipes with varying metal compositions, such as water heaters or pumps, to isolate the metals and reduce potential corrosion caused by electrolysis. These unions effectively maintain water quality and extend the lifespan of plumbing systems by preventing leaks and deterioration due to the chemical reactions caused by metal interaction. The brand's LF3003 Series dielectric unions safeguard water distribution systems, ensuring reliability and durability. They come with a comprehensive assembly consisting of a union nut, two tailpieces and a gasket. This combination creates a robust barrier against electric currents, effectively preventing galvanic corrosion. They have a design with a female iron pipe thread to female brass pipe thread connection, facilitating seamless integration and secure attachment between different types of pipes. These dielectric unions have Buna-N gasket, preventing leakage.

StyleModelBody MaterialGasket MaterialHex SizeInlet MaterialInlet SizeOutlet SizePipe SizePrice (inc. VAT)
ALF3003 1/2-Buna-N-Steel1/2"1/2"-£54.76
ALF3003 1 1/4-Buna-N-Steel1-1/4"1-1/4"-£152.21
BLF3003 2-Buna N-Malleable Iron2"2"-£277.88
ALF3003 1-Buna-N-Steel1"1"-£101.47
ALF3003 1 1/2-Buna-N-Malleable Iron1-1/2"1-1/2"-£209.42
ALF3003 3/4-Buna-N-Steel3/4"3/4"-£66.43
C2 LF3003Lead Free Brass and Malleable IronBuna-N4.125"---2"£174.26
C1 1/2 LF3003Lead Free Brass and Malleable IronBuna-N3.5"---1.5"£147.12
C1/2 LF3003Lead Free Brass and SteelBuna-N1.625"---1/2"£36.47
D11/4 LF3003Lead Free Brass and SteelBuna-N2.75"---1.25"£103.95
C3/4 LF3003Lead Free Brass and SteelBuna-N1.875"---3/4"£44.27
C1 LF3003Lead Free Brass and SteelBuna-N2.25"---1"£57.15
WATTS -

LF3006 Series Dielectric Unions

StyleModelOutlet SizePipe SizeBody MaterialGasket MaterialHex SizeInlet MaterialInlet SizeOutlet MaterialPrice (inc. VAT)
A3/4 LF3006-3/4"Malleable IronBuna-N1.875"---£31.70
B1 1/2 LF3006-1.5"Black Malleable IronBuna-N3.5"---£81.40
C11/4 LF3006-1.25"Malleable IronBuna-N2.75"---£57.00
D1 LF3006-1"Malleable IronBuna-N2.25"---£41.82
E2 LF3006-2"Black Malleable IronBuna-N4.125"---£166.87
F1/2 LF3006-1/2"Malleable IronBuna-N1.625"---£28.31
GLF3006 1/2---Buna N-Malleable Iron1/2"Malleable Iron£34.64
HLF3006 11"--Buna-N-Steel1"Steel£60.42
GLF3006 1 1/41-1/4"--Buna N-Steel1 1/4"Steel£80.56
HLF3006 22"--Buna-N-Malleable Iron2"Malleable Iron£181.23
HLF3006 3/43/4"--Buna-N-Steel3/4"Steel£45.92
WATTS -

LF301 Series Dielectric Unions

StyleModelInlet SizeOutlet SizePrice (inc. VAT)
ALF301 11"1"£15.24
ALF301 1 1/21-1/2"1-1/2"£35.66
ALF301 1 1/41-1/4"1-1/4"£23.43
BLF301 1/21/2"1/2"£9.42
ALF301 22"2"£49.52
ALF301 3/43/4"3/4"£9.46
WATTS -

LF4001E Series Dielectric Unions

StyleModelGasket MaterialInlet SizeOutlet SizePrice (inc. VAT)
ALF4001E 2 1/2Buna-N2-1/2"2-1/2"£210.22
BLF4001E 3/4Buna-N3/4"3/4"£28.59
CLF4001E 1/2Buna N1/2"1/2"£28.59
CLF4001E 1Buna N1"1"£63.23
CLF4001E 1 1/2Buna N1 1/2"1-1/2"£149.80
CLF4001E 1 1/4Buna N1 1/4"1-1/4"£103.09
StyleModelInlet SizeOutlet SizePrice (inc. VAT)
ALF3005A 1/21/2"1/2"£23.05
ALF3005A 3/43/4"3/4"£21.95
WATTS -

LF3001A Series Dielectric Unions

StyleModelGasket MaterialHex SizeInlet SizeOutlet SizePipe SizePrice (inc. VAT)
ALF3001A 3/4Buna-N-3/4"3/4"-£23.70
B1/2 LF 3001A-1/2"Buna-N1.5"--1/2"£18.03
ALF3001A 1Buna-N-1"1"-£42.01
ALF3001A 2Buna-N-2"2"-£147.51
ALF3001A 1 1/2Buna-N-1-1/2"1-1/2"-£119.32
ALF3001A 1 1/4Buna-N-1-1/4"1-1/4"-£70.08
B3/4 LF 3001A-3/4"Buna-N1.625"--3/4"£21.31
B1 LF 3001A-1"Buna-N1.875"--1"£31.75
B11/4 LF 3001A-1 1/4"Buna-N2.25"--1.25"£51.14
B11/2 LF 3001A-1 1/2"Buna-N2.75"--1.5"£71.24
B2 LF 3001A-2"Buna-N3.5"--2"£93.76
CLF3001A 1/2Buna N-1/2"1/2"-£24.96
WATTS -

LF3004 Series Dielectric Unions

Watts LF3004 Series dielectric unions are used in commercial and industrial applications to prevent accelerated corrosion and deterioration in piping systems caused by galvanic and stray currents. They are installed between pipes made from dissimilar metals. These dielectric unions feature steel / iron / galvanised malleable iron / malleable iron & galvanised steel construction for structural rigidity and long service life. They have polysulfone insulation to prevent electrical hazards during operations and come with Buna-N gaskets for secure & reliable sealing between the pipes.

StyleModelOutlet SizePipe SizeBody MaterialGasket MaterialHex SizeInlet MaterialInlet SizeOutlet MaterialPrice (inc. VAT)
A1/2 LF 3004-1/2-1/2"Malleable Iron and Galvanized SteelBuna-N1.625"---£43.14
A3/4 LF 3004 3/4-3/4"Malleable Iron and Galvanized SteelBuna-N1.875"---£49.19
B1 1/4 LF3004-1.25"IronBuna-N2.75"---£62.90
A1 LF 3004-1-1"Malleable Iron and Galvanized SteelBuna-N2.25"---£83.83
C11/2 LF3004-1.5"Galvanized Malleable IronBuna-N3.5"---£82.56
D2 LF3004-2"Galvanized Malleable IronBuna-N4.125"---£131.62
ELF3004 11"--Buna N-Steel1"Steel£60.42
ELF3004 1 1/21-1/2"--Buna N-Malleable Iron1 1/2"Malleable Iron£122.43
BLF3004 1 1/41-1/4"--Buna-N-Steel1-1/4"Steel£80.56
ELF3004 1/21/2"--Buna N-Steel1/2"Steel£40.26
BLF3004 22"--Buna-N-Malleable Iron2"Malleable Iron£181.23
BLF3004 3/43/4"--Buna-N-Steel3/4"Steel£45.92
WATTS -

LF3002 Series Dielectric Unions

StyleModelInlet MaterialInlet SizeOutlet SizePrice (inc. VAT)
A1 LF3002---£31.86
BLF3002 3/4Iron3/4"1/2"£39.06
BLF3002 1Steel1"3/4"£56.79
WATTS -

Dielectric Unions

StyleModelInlet MaterialMfr. SeriesGasket MaterialInlet SizeInlet Thread TypeInlet TypeMax. Working PressureInlet ConnectionPrice (inc. VAT)
AA3200 3Cast Iron3200Buna N3"NPTFemale Threaded175 PSIFemale Threaded£550.89
RFQ
AA3200 2 1/2Cast Iron3200Buna N2 1/2"NPTFemale Threaded175 PSIFemale Threaded£446.21
RFQ
AA3200 4Cast Iron3200Buna N4"NPTFemale Threaded175 PSIFemale Threaded£828.77
RFQ
BLF3100M3 2 1/2IronLF3100Buna N2 1/2"NPTFemale Threaded175 PSIFemale Threaded£442.18
RFQ
CLF3100M3 3IronLF3100Buna N3"NPTFemale Threaded175 PSIFemale Threaded£606.48
RFQ
D3004 1 1/4Iron-Buna N1 1/4"NPT-250 PSIFemale Threaded£66.03
RFQ
E3003 3/4Iron-Buna N3/4"NPT-250 PSIFemale Threaded£54.76
RFQ
D3004 1/2Iron-Buna N1/2"NPT-250 PSIFemale Threaded£33.03
RFQ
CLF3100M3 4IronLF3100Buna N4"NPTFemale Threaded175 PSIFemale Threaded£1,605.19
RFQ
F3001A 1 1/2Iron3001ABuna-N1-1/2"-Female Threaded--£98.03
GLF3007 1/2IronLF3007Buna N1/2"IPSMale Threaded250 PSIMale Threaded£50.74
F3001A 1 1/4Iron3001ABuna-N1-1/4"-Female Threaded--£57.47
F3001A 2Iron3001ABuna-N2"-Female Threaded--£121.17
HLF3007 3/4IronLF3007Buna-N3/4"-Male Threaded--£56.79
I3001A 1/2Iron-Buna N1/2"NPT-250 PSIFemale Threaded£19.56
RFQ
WATTS -

Flange Bolt Insulator Kit

ModelItemPrice (inc. VAT)
INS-KIT 3/4CB4PGJ£10.38
WATTS -

Flange Bolt Insulator Kit

ModelItemPrice (inc. VAT)
INS-KIT 5/8CB4PGG£9.28
WATTS -

Dielectric Union 3/4 x 1/2 Inch Fip x Solder

ModelItemPrice (inc. VAT)
3/4x1/2 LF 3002-3/4X1/2AE3JGP£20.36
WATTS -

Dielectric Union Insulator Kit

ModelItemPrice (inc. VAT)
INK-B-KITCB7BYU£5.94
WATTS -

Dielectric Union Insulator Kit

ModelItemPrice (inc. VAT)
INK-F-KITCB7BYR£8.88
WATTS -

Dielectric Union Insulator Kit

ModelItemPrice (inc. VAT)
INK-D-KITBZ2VAV£6.67
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Frequently Asked Questions

Can a dielectric union be used between stainless steel and copper pipes?

When copper is used with carbon steel or galvanised steel, dielectric unions must be used to electrically insulate each material. But when copper is connected with stainless steel, a brass / bronze fitting can provide sufficient electrical separation between the two materials.

How does the dielectric union break continuity?

When dielectric unions are connected between copper and steel piping, they ground the electric current and break the continuity for complete insulation between the two environments.

How to install the Watts dielectric union?

  • Wrap several layers of sealing tape over the threads of the steel pipe.
  • Install the threaded end of the dielectric union to the steel pipe and turn it clockwise with the help of a pipe wrench.
  • Next, slide the union nut over the end of the copper pipe with an open threaded end facing out. Also, slide the plastic insulator over the copper pipe.
  • Install the copper solder adapter onto the copper pipe and sweat adapter using a propane torch.
  • Allow the pipe to cool.
  • Slide the rubber gasket between the union nut and the union body and assemble it.
  • Inspect to ensure a watertight connection.

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