EN 1515-4:2021/AC:2022

Flanges and their joints - Bolting - Part 4: Selection of bolting for equipment subject to the Pressure Equipment Directive 2014/68/EU

Scope

This document is applicable to the selection of bolting for flanged joints on equipment subject to the Pressure Equipment Directive 2014/68/EU.
It specifies standards and additional requirements for dimensions, material properties and technical conditions of delivery for bolting.
NOTE 1 Washers are not within the scope of this document.
The selection is based on commonly used bolting. It covers common temperature ranges of the general service of flanges.
When selecting bolting according to this document it is essential to take into account environmental conditions and other parameters including type of fluids, corrosion hazards, sour service, low temperature brittle failure and relaxation at elevated temperatures.
The purpose of this document is to provide a selection of most commonly used bolting types and bolting material combinations.
It is not the intention to specify all possible applications but to give guidance on the most common applications. For example, application limits for material in the creep range are not explicitly covered in this document. Where material standard provides mechanical properties for the creep range respective reference is made in Table 3.
NOTE 2 Special services and ambient conditions may require the application of coatings. It is the purchaser’s option to decide on this. Depending on the coating used, a verification of the temperature ranges given in Table 3 and Table 4 may be required.
NOTE 3 In Annex B there are bolting types and bolting material combinations according to commonly used national standards other than those listed in Table 2, Table 3 and Table 4.