Main pressure-bearing parts PED 97/23/EC

[oosnicram]

https://www.netinform.de/vorschriften/dg/ped_en/g7_6.htm

"Question:
The 2nd paragraph of section 4.3 of Annex I gives requirements for the main pressure-bearing parts.
How are they defined?

Answer:
The main pressure-bearing parts are the parts, which constitute the envelope under pressure, and the parts which are essential for the integrity of the equipment.
Examples of main pressure-bearing parts are shells, ends, main body flanges, tube sheet of exchangers, tube bundles.
The materials for these main pressure-bearing parts of equipment of categories II to IV shall have a certificate of specific product control (see Guideline 7/5).
See also guideline 7/8 for bolting parts (fasteners)."

WHAT ABOUT OTHER PARTS SUCH AS: NOZLLES ATTACHED TO SHELL/DISHED END, FLANGES, BOLTING PARTS, MANHOLE ? AREN'T THEY MAIN PRESSURE-BEARING PARTS? Are they "only" pressure bearing parts and a test report is sufficient ?

I UNDERSTAND THAT MAIN BODY FLANGE IS ATTACHED DIRECTLY TO SHELL/DISHED END, SO BOLTING PARTS ONLY FOR THAT MAIN FLANGE REQUIRE CERTIFICATE 3.1 ?

 

[XL83NL]

Does a nozzle constitute to the envelope of pressure? I.e. does it feel pressure?
Does a flange constitute to the envelope of pressure?

I can go on, you see my point. Answer is yes. For bolling iT may differ on interpretation, but I would always require 3.1 certs dor bolting

 

[Drexl]

From reading PED + guideline my interpretation was also that bolts of pressure bearing flanges such as manholes and nozzle flanges need a 3.1.

However after consulting with a NoBo a few years back I got a different answer. A 2.2 was enough for the bolts in some cases.

Have to see if I find the reply/reasoning behind this..

 

[TWP]

Read the published official PED guidelines.

http://ec.europa.eu/enterprise/sectors/pressure-and-gas/documents/ped/guidelines/index_en.htm

For bolting >> Guideline 7/8

Guideline related to: Annex 1, section 4
Question: What are the certificates required for bolting parts?

Answer: The bolting parts (screw, nut, stud, etc) are joining components.
When these components contribute to the pressure resistance, their
materials shall fulfil the relevant requirements of annex I, section 4.

Regarding section 4.3 of Annex I, a bolt is not considered to be a main
pressure bearing part unless its failure would result in a sudden discharge
of pressure energy.

When bolts are used as
− main pressure bearing parts a certificate of specific product control is
required (unless the item of pressure equipment itself is in Category I)
− pressure bearing parts a test report is sufficient,
− non pressure bearing part a certificate of compliance is sufficient.
(refer to guideline 7/5).
-----------------------------
For almost 15 years, in Europe we use bolting with EN 10204, type 2.2 insp documents for piping & press vessels.
Never had any problems with that.

 

[OSIRIS7]

No you will not get problems with that. Untill something happens. And an investigation is started. The manufacturer (not nescesarily the maker of the vessel or the pipeline) is allways fully responsible. Even if the NoBo checked the design.

Even pipe support materials have in some circumstances certificates of specific control. For instance when designing according EN 13480. See one of the annexes of EN 13480-3.