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ASME PTB-11-2017 pdf download

ASME PTB-11-2017 pdf download.Guide for ASME BPVC Section I Stamp Holders.
7 ESSENTIAL SAFETY REQUIREMENTS (ESR) (ARTICLES 4 AND 6, ANNEX I OF THE PED) 7.1 Introduction The technical requirements concerning the Pressure Equipment itself are included in Annex I of the PED under the designation ESR. The following principles apply. (a) All pressure equipment above the thresholds mentioned in Article 4 of the PED (i.e., classified in Hazard Category I, II, III, or IV) shall comply with all these ESR. They concern the various steps of the construction: design, material selection, fabrication, inspection, and safety devices. (b) These ESR are generally formulated in general terms of safety objectives, such as, “Pressure Equipment shall be constructed in such a way to ensure its safety in reasonable foreseeable conditions.” The PED does not provide the means to achieve these requirements; this is the role of the Harmonized Standards. Some quantitative requirements are provided by PED §7 of Annex I, which “apply as a general rule.” Manufacturers can depart from these quantitative requirements, but they shall convince the NB that “they have taken appropriate measures to achieve an equivalent overall level of safety.” (c) It is the role of European Committee for Standardization (CEN) Harmonized Standards (harmonized to the PED), such as EN13445 for Unfired Pressure Vessel developed by CEN/TC54), to quantify each of these requirements. As a consequence, this gives them a presumption of conformity to the PED (see PED Article 12-§1). However, use of these Harmonized Standards is not compulsory. The Manufacturer may construct its pressure vessel using any Code or Standard but must be able to demonstrate to the NB that the vessel complies with each of the ESR of PED Annex I. Or, the Manufacturer shall show that it has used a quantitative requirement different from the Harmonized Standards, provided an equivalent level of safety is achieved. (d) The Manufacturer is free to use one of the following three options to prove that this Equipment complies with the ESR. (1) use of the EN Harmonized Standard, which will give presumption of conformity to the ESR (2) use of a recognized Code like ASME BPVC, French Code for Construction of Unfired Pressure Vessel (CODAP), etc. (supplemented by additional requirements to ensure compliance with the PED) (3) by applying directly the ESR and providing calculation sheets carrying out tests, etc. In options 2 and 3, the Manufacturer will have to convince the NB of its compliance with the ESR. (e) The stringency of some of these ESR depend on the Hazard Category of the Equipment, especially: (1) approval of welding operating permanent joining procedures (Annex I-§3.1.2 of the PED) (2) approval of welders (Annex I-§3.1.2 of the PED) (3) approval of non-destructive test personnel (Annex I-§3.1.3 of the PED) (4) types of material certificate (Annex I-§4.3 of the PED). 7.2 General Discussion of ESR (Annex I of the PED) 7.2.1 Preliminary Remarks (a) All equipment above the thresholds specified in PED Article 4-§1 (i.e., Equipment classified in Categories I, II, III, and IV) shall meet each of the ESR of Annex I of the PED. This applies to assemblies (Article 4-§2 of the PED), taking into account the derogation specified in clause Article 4-§2.3 (see Annex I-§2.8 of the PED).
b) The ESR are mandatory. These are expressed qualitatively in terms of general purposes. Only some numerical values are given in Annex I-§7 of the PED (joint efficiency, proof test pressure, etc.). The Manufacturer is not obliged to use these values provided an equivalent overall level safety has been achieved (Annex I-§7 of the PED). General (Annex I-§1 of the PED) Equipment shall be constructed in such a way that their safety is ensured (Annex I-§1.1 of the PED). The Manufacturer shall carry out an analysis of hazards and risks, which shall be used as indicated in Annex I- §1.2 and Annex I-§1.3 of the PED. Design (Annex I-§2 of the PED) General (Annex I-§2.1 of the PED) Pressure equipment shall be “properly designed” to ensure that the equipment will be safe throughout its intended life, taking into account (a) suitable safety margins against the different failure modes (b) loads corresponding to the intended use (pressure, temperature, wind, earthquake, etc.) (c) expected working conditions (corrosion, erosion, fatigue, etc.), (Annex I-§2.2.1 of the PED). Design Method Two methods for design are proposed (Annex I-§2.2.2 of the PED): (a) Calculation Method. This method is applicable to all cases (Annex I-§2.2.3 of the PED). (1) This method shall specify the maximal allowable stresses to prevent possible failure modes including creep, corrosion, fatigue, and instability (Annex I-§2.2.3a of the PED). (2) The allowable general membrane stress, Sa, is defined below, for each type of material (Annex I-§7.1.2 of the PED).

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