Galvanized pipe thread

Galvanized pipe thread

PostBy: coaledsweat On: Sat Dec 22, 2007 7:24 pm

If you own a home built prior to 1970, don't be alarmed by the following as it doesn't apply.

"Galvanized pipe should not be used", I'll bet you see that in a few of my posts. I figured I would tell you why. Since the '70s, a lot of our plumbing parts are coming from overseas, China, India, Singapore etc. In spite of industry and customer standards, for the most part it is now the worst quality plumbing material I have ever seen. A list of reasons it is a poor choice.

If you do use it, everything needs to be galvanized and or isolated.

Unless it is pre '70s or spec pipe, DO NOT USE ON STEAM! It will burst.

If you use one piece of galvanized in your system, it needs to be isolated or you subject your system to two forms of corrosion. One is Galvanic action which is caused by dissimilar metals.
If there is an electrical potential present you are subject to electrolysis and in this case, zinc is not the sacrificial lamb (unless your plumbing is in saltwater at about 50,000 PPM). Your boiler and plumbing are.

Galvanized found in hardware stores is most often hot dipped in zinc instead of plated. Again, poor quality control and a really bad product. This stuff is the worst thing you can use. The dipped zinc can fall off and jam pumps and valves.

I am not sure what causes it, but I know copper does poorly when galvanized is present. Lots of pinholes.

I don't recommend it for stovepipe either, when it overheats the galvanized is gone, where it goes I do not know. :roll:
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Galvanized pipe thread

PostBy: Wood'nCoal On: Sat Dec 22, 2007 7:46 pm

I know about the imported copper and brass fittings. Every time I place an order for fittings they have "Taiwan" or "China" all over them, and I do wonder about the quality, and I also wonder why they don't say "USA" on them. I think it's a plot to blanket America with substandard boiler drain valves that will fail simultaneously across America.
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Galvanized pipe thread

PostBy: Ed.A On: Sat Dec 22, 2007 9:47 pm

Wood'nCoal wrote:I know about the imported copper and brass fittings. Every time I place an order for fittings they have "Taiwan" or "China" all over them, and I do wonder about the quality, and I also wonder why they don't say "USA" on them. I think it's a plot to blanket America with substandard boiler drain valves that will fail simultaneously across America.


Haha, nice theory.
A customer of mine is a self-employed plumbing contractor, he was telling me that the quality level is extremly poor, they claim ("they" meaning China) that they follow ASTM specifications for fittings but they don't in actuality. He told me they did a impromptu survey and they found 65-75 % of the threads did not meet the quality standards ( like thread engagement and sizes) required. He says they teflon tape and go to install only to find out they lock up after 2-1/2 turns or so...not good.
I was reading in one of my trade (manufacturing) magazines about companies that a pulling back from China becuase they found out the substandard products were actually costing more that it was worth. Things like the heat treat specs required were falsified and such, liabilty concerns are driving people/companies to rethink the labor cost savings.
Ed.A
 
Hot Air Coal Stoker Stove: Alaska Channing III/ '94 Stoker II
Coal Size/Type: Rice


Re: Galvanized pipe thread

PostBy: Wood'nCoal On: Sat Dec 22, 2007 10:05 pm

I have noticed times when assembling threaded brass fittings that some pieces screw together farther then other identical pieces. I am not happy about the trade imbalance, how the companies that flood the market with foreign products operate, it seems that everything is made somewhere else now (except coal). I would always seek out US made products, but big business and high profits have made it almost impossible to find some items that are made here. Sorry, this is a really sore subject with me. :blowup:
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Galvanized pipe thread

PostBy: coaledsweat On: Sat Dec 22, 2007 10:28 pm

Don't want to interrupt the beating China is getting here, but I forgot one in my first post.

Galvanized does poorly with heated water, over 140* it eats it much faster.
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Galvanized pipe thread

PostBy: Wood'nCoal On: Sat Dec 22, 2007 10:34 pm

Sorry, I realize I went off topic, it makes me so mad, like a dirty fork in a restaurant (No, Mongo, never kill a customer!!!).
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Galvanized pipe thread

PostBy: coaledsweat On: Sat Dec 22, 2007 10:43 pm

Wood'nCoal wrote:Sorry, I realize I went off topic, it makes me so mad, like a dirty fork in a restaurant (No, Mongo, never kill a customer!!!).


I was enjoying it!
coaledsweat
 
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Re: Galvanized pipe thread

PostBy: Wood'nCoal On: Sat Dec 22, 2007 11:20 pm

coaledsweat wrote:
Wood'nCoal wrote:Sorry, I realize I went off topic, it makes me so mad, like a dirty fork in a restaurant (No, Mongo, never kill a customer!!!).


I was enjoying it!


So I should go back to the rant??
Wood'nCoal
 
Stoker Coal Boiler: 1959 EFM 350
Hand Fed Coal Stove: Harman Magnafire Mark I
Coal Size/Type: Rice and Chestnut
Other Heating: Fisher Fireplace Insert

Re: Galvanized pipe thread

PostBy: Ed.A On: Sun Dec 23, 2007 1:06 am

Wood'nCoal wrote:So I should go back to the rant??


Uhmmm...yes.
Ed.A
 
Hot Air Coal Stoker Stove: Alaska Channing III/ '94 Stoker II
Coal Size/Type: Rice