Bolting for DIN Flanges

[Weegie]

Hi,

I'm looking for help/clarification on the use of machine bolts and/or studbolts on DIN flanges.
I have a table (catalog cut) that shows stud bolts or machine bolts can be used on PN 20 (CL150)& PN 50 (CL 300) flanges.
The same table shows stud bolts only for PN100/150/250/420.
I also found a table at Maryland Metrics which shows machine bolts only on PN6/10/16/25/40/64.
Can I conclude that machine bolts or stud bolts can be used on (metric) flange ratings less than PN100 and for PN100 and higher, use only stud bolts ?
Any other links and/or tables with bolt dimensions/types would be greatly appreciated.

Many thanks.

 

[micalbrch]

It is unfortunately not as easy as you might think. Flange connections for pressure vessel acc. to the European Pressure Vessel Directive have an own standard - just an example. Temperature and bolt/stud material are other issues. I know that the standard EN 1514 covers flange connections but I do not know any legal source where you can get it free of charge.

 

[europipe]

Never heard of PN20 and PN50 (maybe a wrong interpretation of 150 and 300#?)
You can use both bolts ore studbolts, just what the pipespec. proscribes.
Studbolts are better because of spreading of forces when mounting.

 

[OSIRIS7]

If you mean hexagon head bolts by "bolts", then I would strongly advise stud bolts from PN40 and up. The transition from the hex head to the bolt is weaker than nuts on both ends of threading.

Maybe there is something about bolting in EN 13480 (pressure piping or EN 13455 (pressure vessels), but we use stud bolts in general, never hex head bolts. Threaded studs acoording EN 1515-1 Annex A and nuts according EN 4032. Be aware that for use in pressure equipment according to PED, EN has material EN 10269 and dimensions in before named EN, but there is no information regarding the manufacturing, heat treatment etc. of the bolt and nut itself. This is why in Germany the AD 2000 Merkblatt W7 of may 2008 is a very usefull guide to understand what to demand in a specific certificate 3.1 (under conditions) or 3.2. It is not abnormal to ask a statement that testing, inspection and production is according to AD 2000 W7.

 

[Weegie]

Gents, thanks for all your replies.
There's lots of info on the net on stud bolts that are for ANSI flanges. On my search, some companies convert ANSI ratings typically CL 150/300/600/900 etc, into DN equivalents of PN 20/50/100/150 (Pipeline Supplies of Australia). Other companies go in DN sizes of 6/10/16/25/40/64 and upwards with no ANSI equivalents.
Maryland Metrics have a chart with these flange ratings and they do give bolt diameters and lengths but, the dimensions are for machine bolts. Unfortunately, they do not carry an equivalent for stud bolts on their site.
The isometrics produced by my company do not detail gasket size or stud bolt lengths/diameters, only the quantities and leave it up to the pipe spool fabricator to select the appropriate sizes.
I did not think looking for 'metric' stud bolt dimensions would be such a difficult task.

Again thanks for your input.