Is it necessary or desirable to use a dielectric union or coupling when
connecting new gas lines to a gas meter? I have seen this done in some
installations but not others.

What is the correct thing to do?

Thanks for any replies / assistance.

Smarty

Smarty wrote:
Is it necessary or desirable to use a dielectric union or coupling when
connecting new gas lines to a gas meter? I have seen this done in some
installations but not others.

What is the correct thing to do?

Thanks for any replies / assistance.

Smarty



It depends upon whether your gas utility uses metal supply lines with
"active cathodic protection" or not.

If they do, then they apply a low voltage to their pipes to prevent
electrolytic corrosion and the dielectric unions are needed to avoid
shorting that voltage to ground through the home's plumbing and/or
electrical grounding system.

Best to check with your gas utility and do what they say. AFAIK
nonmetalic supply lines are the defacto stardard for new installations
nowadays.

HTH,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

In most cases an insulating coupling is part of the meter set supplied by
the utility, of course, this may vary in some localities.

"Jeff Wisnia" wrote in message
et...
Smarty wrote:
Is it necessary or desirable to use a dielectric union or coupling when
connecting new gas lines to a gas meter? I have seen this done in some
installations but not others.

What is the correct thing to do?

Thanks for any replies / assistance.

Smarty

It depends upon whether your gas utility uses metal supply lines with
"active cathodic protection" or not.

If they do, then they apply a low voltage to their pipes to prevent
electrolytic corrosion and the dielectric unions are needed to avoid
shorting that voltage to ground through the home's plumbing and/or
electrical grounding system.

Best to check with your gas utility and do what they say. AFAIK nonmetalic
supply lines are the defacto stardard for new installations nowadays.

HTH,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

Thanks Jeff (and 73's) - I was unaware that the utilities used an active
method to fight electrolytic erosion / transfer. This is a retrofit to an
existing meter and a 50+ year old underground supply line, so I think it
best I put the dielectric union in "just in case".

Thanks again,

Smarty (another older, retired E.E.)


"Jeff Wisnia" wrote in message
et...
Smarty wrote:
Is it necessary or desirable to use a dielectric union or coupling when
connecting new gas lines to a gas meter? I have seen this done in some
installations but not others.

What is the correct thing to do?

Thanks for any replies / assistance.

Smarty

It depends upon whether your gas utility uses metal supply lines with
"active cathodic protection" or not.

If they do, then they apply a low voltage to their pipes to prevent
electrolytic corrosion and the dielectric unions are needed to avoid
shorting that voltage to ground through the home's plumbing and/or
electrical grounding system.

Best to check with your gas utility and do what they say. AFAIK nonmetalic
supply lines are the defacto stardard for new installations nowadays.

HTH,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

Thanks also for your reply, EXT.


"EXT" wrote in message
anews.com...
In most cases an insulating coupling is part of the meter set supplied by
the utility, of course, this may vary in some localities.

"Jeff Wisnia" wrote in message
et...
Smarty wrote:
Is it necessary or desirable to use a dielectric union or coupling when
connecting new gas lines to a gas meter? I have seen this done in some
installations but not others.

What is the correct thing to do?

Thanks for any replies / assistance.

Smarty

It depends upon whether your gas utility uses metal supply lines with
"active cathodic protection" or not.

If they do, then they apply a low voltage to their pipes to prevent
electrolytic corrosion and the dielectric unions are needed to avoid
shorting that voltage to ground through the home's plumbing and/or
electrical grounding system.

Best to check with your gas utility and do what they say. AFAIK
nonmetalic supply lines are the defacto stardard for new installations
nowadays.

HTH,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

Smarty wrote:

Thanks Jeff (and 73's) - I was unaware that the utilities used an active
method to fight electrolytic erosion / transfer. This is a retrofit to an
existing meter and a 50+ year old underground supply line, so I think it
best I put the dielectric union in "just in case".

Thanks again,

Smarty (another older, retired E.E.)



The tecnical term for that is "Impressed Current Cathodic Protection".
There's a little about it he

http://en.wikipedia.org/wiki/Cathodic_protection

73s,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

Good info I was unaware of. Thanks again!

Smarty


"Jeff Wisnia" wrote in message
et...
Smarty wrote:

Thanks Jeff (and 73's) - I was unaware that the utilities used an active
method to fight electrolytic erosion / transfer. This is a retrofit to an
existing meter and a 50+ year old underground supply line, so I think it
best I put the dielectric union in "just in case".

Thanks again,

Smarty (another older, retired E.E.)


The tecnical term for that is "Impressed Current Cathodic Protection".
There's a little about it he

http://en.wikipedia.org/wiki/Cathodic_protection

73s,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.