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Pipe and fittings Classing

Posted: Wed May 16, 2007 3:07 am
by skinner
Currently on my pneumatic, I have Class 18 and class 12 PVC as a chamber.
The class 18 being the endcaps and the class 12 being the chamber length.

I was wondering if the class number is same as pressure number? ie. PN12 is rated to 12 bar.

thanks in advance.

--Skinner

Posted: Wed May 16, 2007 3:19 am
by MrCrowley
Sure is. PN mean 'Pressure Number' Then the number is the rating in 'BAR'.

Posted: Wed May 16, 2007 3:20 am
by skinner
i know all that stuff.

i was wondering if pipe classifications (class 18 etc.) is the same as Pressure numbers.

Posted: Wed May 16, 2007 3:42 am
by MrCrowley
Pressure numbers?
You asked
"was wondering if the class number is same as pressure number? ie. PN12 is rated to 12 bar."
And the answer is yes. PN12 is rated to 12BAR
So PN18 is rated to 18BAR or 290PSI

Posted: Wed May 16, 2007 3:45 am
by skinner
I see what you mean.
But is class 18 pvc, the same as PN18 pvc?

Posted: Wed May 16, 2007 3:58 am
by MrCrowley
Yeah, There was an old system where they had Class 'A-F' I think it was. 'F' being the highest rated, then it must of changed to Class XX where 'XX' is the pressure number in BAR, and now its PNXX. So It should be the same.

Posted: Wed May 16, 2007 5:52 am
by rna_duelers
Also there is a second number next to the PN rating not to get mixed up with the actualy rating which one of my friends did. It went like this PN 9 40 and he thought it was rated to 40bar but that is the pipe diameter.

Metric PN pipe rating systems also have a 3X burst pressure rating,just a lilttle bit of information for you.

Posted: Wed May 16, 2007 2:09 pm
by MrCrowley
Hmm Strange all my pipe says for diameter is DNXX where XX is the diameter.