Expansion joint spark testing
Expansion joint spark testing
(OP)
I know that when dealing with things like lined pipe or lined valves, spark testing for holidays is a good idea.
However, I'm looking at some PTFE bellows expansion joints and some elastomeric expansion joints. Is there any reason why you would spark test these?
It seems to me that any holes in these types of joints would make themselves evident during the pressure test since there's no external steel or iron casing to hold the pressure in. Further, there's not steel or iron casing to be corroded from the inside out.
I'm not an expert on these things, so if anyone can think of any reason to spark test these things, even one unrelated to what I'm thinking of, feel free to pile on because it's good information to have.
Thanks!
However, I'm looking at some PTFE bellows expansion joints and some elastomeric expansion joints. Is there any reason why you would spark test these?
It seems to me that any holes in these types of joints would make themselves evident during the pressure test since there's no external steel or iron casing to hold the pressure in. Further, there's not steel or iron casing to be corroded from the inside out.
I'm not an expert on these things, so if anyone can think of any reason to spark test these things, even one unrelated to what I'm thinking of, feel free to pile on because it's good information to have.
Thanks!





RE: Expansion joint spark testing
since these are solid ptfe or elastomer, that particular test would be not only unjustified but impossible to do without the steel to conduct the signal.
RE: Expansion joint spark testing
I guess I'm really asking if anyone knows of any reason OTHER than holiday testing to do any kind of spark test.
RE: Expansion joint spark testing
rmw
RE: Expansion joint spark testing
No matter how the joint has been made you can ensure there are no defects in the material very easily before it is installed so giving time to carry out repairs if necessary. The spark tester will "jump" about 1.5 inches so either hold a piece of steel on one side and test from the other, or paint one side with graphite dust which will then act as the earth conductor instead of the steel.
cheers CM
RE: Expansion joint spark testing
It's my feeling that there is no reason to incur the added costs of spark testing since it would not show us anything that the pressure test wouldn't. I know that the mfg. will do it for an additional cost, so I'm not worried at all about whether or not it can be done. I just wanted to make sure there was no reason to do one that I hadn't thought of, and I'm pretty confident that there isn't and my bases are covered when the client asks about it.