1. Pressure Equipment Workshop September 2007 – Day 1
Pressure Equipment Directive
(PED)
Classification
Ed Haynes, Guy Baylac

2. Criteria for classification
Two fluid groups
- Group 1: Positive list of 7 dangerous fluid types as defined by Directive 67/548/EEC
- Group 2: Other fluids
Physical state of fluid - gaseous, - liquid
Indication of stored “energy” PS·V or PS·DN (piping etc

3. Determination of applicable category
Classification
Group 1 fluid
Group 2 fluid
Vessels
gaseous
Table 1
Table 2
liquid
Table 3
Table 4
Piping
Table 6
Table 7
Table 8
Table 9
Pressure
Accessories
volume
according to tables 1-4 DN
according to tables 6-9
Safety
general
Category IV
specific
Category of respective equipment
Assemblies
According to highest element (except safety acc.)

4. Conformity assessment tables (A)
Vessels for dangerous gases Vessels for non-dangerous liquids
(Table 1) (Table 4)

5. Conformity assessment tables (B)
Piping for dangerous gases Piping for non-dangerous liquids
Table Table 9

6. Examples for single items
Use rules in PED Annex II tables or software available from some Notified Bodies
Related Guidelines – series 2 on
Note – guidelines are indicative. They are not exhaustive and not legally binding. You must read all the text – the following examples are only extracts

7. Extracts of some Guidelines
There is a contradiction between the requirements in article 3 paragraph 1.4 and those in annex II point 3. Can pressure accessories be classified as "article 3.3" as indicated in the tables in annex II or must all of them satisfy the essential requirements as indicated in article 3 paragraph 1.4? SHORT ANSWER – use Annex II
Guideline 2/2: The Directive uses the notion of DN. How to apply the Directive for classifying the tubular products or accessories for which the notion of DN does not exist (copper tubes, plastic valves, hollow sections....)? SHORT ANSWER internal cross-section

8. Extracts of some Guidelines
How should vessels and piping for superheated water be classified? SHORT ANSWER see tables 2, 5 and/or 7
Guideline 2/4: (Controversial)
Which type of pressure equipment is a heat exchanger ?
Guideline 2/5: Some warm water generators having a volume greater than 2 L are intended to generate water at a temperature less than 110 °C, but are fitted with a safety temperature limiter which is set to a temperature of 120 °C. What value of maximum allowable temperature, TS, shall be declared by the manufacturer ?
SHORT ANSWER TS = 120 degrees C

9. Extracts of some Guidelines
Guideline 2/6: How should a fired or otherwise heated equipment be classified if a fluid other than water is being heated ?
SHORT ANSWER – NOT table 5
Guideline 2/7: Article 9 classifies fluids with reference to Article 2 (2) of Directive 67/548/EEC. Does this mean that all fluids classified as dangerous are group 1?
A LONG ANSWER
Guideline 2/8: How should a vessel which is intended to contain water below 100 °C be classified when there is a marginal gas cover ? SHORT ANSWER – table 4

10. Extracts of some Guidelines
Guideline 2/9: Which pressure and volume values must be used to determine the category of vessels used as gas-loaded accumulators, or other vessels with a flexible or non fixed membrane, given that these are made up of two chambers with different fluids?
SHORT ANSWER – Article 9.3
Guideline 2/10: If a vessel contains a fluid which meets the conditions of the introductory paragraph to Article 3, paragraph 1.1(a) (e.g. air) and a liquid which meets the conditions of the introductory paragraph to Article 3, paragraph 1.1(b) (e.g. water) - how shall the vessel be classified? SHORT ANSWER – Higher category - see also 2/8 and 2/9

11. Extracts of some Guidelines
Guideline 2/11: When is it possible for a manufacturer to apply a module from a higher category and what are the consequences ?
IMPORTANT PART OF ANSWER – The module used for conformity assessment does not change the classification of the equipment
Guideline 2/15: Does the classification of the pressure cookers in category III for the assessment of the design mean that also the ESRs are linked to category III? SHORT ANSWER – NO

12. Assemblies
Related Guidelines – series 3 on
Note – guidelines are indicative. They are not exhaustive and not legally binding. You must read all the text – the following examples are only extracts

13. Extract of some Guidelines
Guideline 3/1: Must the global conformity assessment procedure be applied to assemblies covered by article 3.2.1, e.g. to boilers, even if the assembling is done under the responsibility of the user?
SHORT ANSWER – NO
Guideline 3/2: Are joining operations on site covered by the PED? ANSWER IN TWO PARTS
Guideline 3/3: The effect of the derogation in Article from the introductory paragraph in Article 3.2 is not clear. In the circumstances, how should Article be applied ? ANSWER IS COMPLICATED

14. Extract of some Guidelines
Guideline 3/4: What shall be the minimum extent of the assembly "boiler" which shall be subjected to a global conformity assessment procedure in accordance with article 3 section 2.1 ?
SHORT ANSWER See EN
Guideline 3/5: Shall the assemblies defined in the article 3 paragraph 2.3 carry the CE-marking? SHORT ANSWER – YES … but
Guideline 3/6: Must a hydrostatic pressure test be carried out on an assembly and should the value laid down in section 7.4 then be followed ? COMPLEX ANSWER