ASME PTB-10:2015 pdf free download – Guide for ASME Section VIII Division 1 Stamp Holders
5.1 Level of Hazards in Pressure Equipment
PED is a hazard-directed Directive, rather than a product Directive. Its primary goal is to prevent potential hazards due to internal pressure in Equipment.
Several levels of hazards are considered in the PED, which have practical consequences for the Equipment both for the stringency of the Essential Safety Requirements and Conformity Assessment Procedures to be carried out. “Levels” are not used in the PED, but are used in the Guide to help explain the various Categories and those areas outside the numbered Categories.
Level 1 The pressure is 0.5 bar or lower: There is no significant hazard, and the equipment is outside the scope of the PED.
Level 2 The pressure is above 0.5 bar, but the Equipment presents only a minor pressure hazard, which does not require a Conformity Assessment. This is often called Category 0, which defines the threshold above which the Equipment is classified in Hazard Categories I, II, III, or IV.
Level 3 The pressure hazard level is low: The equipment is classified in Hazard Category I. There is no intervention of the NB.
Level 4 The pressure hazard level is moderate: The equipment is classified in Hazard Category II. The NB will check the Fabrication.
Level 5 The pressure hazard level is high: The equipment is classified in Hazard Category III. The NB will check the Design and the Fabrication.
Level 6 The pressure hazard level is very high: The equipment is classified in Hazard Category IV. The NB will perform increased check of the Design and Fabrication.
Therefore, there are two main cases for Pressure Equipment:
(a) the Equipment is below the thresholds of Category 0, Levels 1 and 2.
(b) the Equipment is above the thresholds of Category 0, Levels 3 to 6.
5.2 Equipment in Category 0 (Article 4-§3 of the PED)
This concerns all the equipment that is at or below the thresholds defined in Article 4-§3 of the PED (see Fig. 4-1 in this Guide). These thresholds depend on the type of the Equipment, the dangerousness of the fluid, and the pressure (PS) and volume (V) of the Equipment. This is Category 0 (which does not appear as such in the PED) and is covered by Article 4-§3 of the PED.
Such equipment
(a) is not subject to the ESR: it must be constructed in accordance with Sound Engineering Practice
(b) is not subject to the Conformity Assessment Procedures
(c) is not subject to the Declaration of Conformity: it must only bear the identification of the manufacturer and be accompanied by instructions for use
(d) must not bear the CE Marking; however, it has the benefit of the free movement throughout the EU.
5.3 Equipment in Hazard Categories I to IV (Article 4-§1 of the PED)
Equipment that is above the thresholds defined in Article 4-§3 of the PED is classified in Hazard Category I to IV, depending on their level of hazard. This Equipment
(a) is subject to ESR
(b) is subject to the Conformity Assessment Procedure
(c) is subject to the Declaration of Conformity
(d) must bear the CE Marking