BS DD CEN/TS 1591-4:2007 Flanges and their joints - Design rules for gasketed circular flange connections - Qualification of personnel competency in the assembly of bolted joints fitted to equipment subject to the Pressure Equipment Directive
1.1 General
This European Technical Specification establishes a process for training and competency assessment of personnel
who disassemble, assemble and tighten bolted joints such as fitted to equipment subject to the Pressure
Equipment Directive 97/23/EC (PED), in the content of this Technical Specification named "PED".
1.2 Requirement for competency
Training and competence, experience and knowledge are often confused with each other. Training is no guarantor
of competence, nor is experience a guarantor of knowledge and understanding. Training, experience,
and assessment of knowledge are all required to achieve competence.
Design codes for mechanical joints (see for example EN 1591-1 or CEN/TS 1591-3) increasingly require controlled
bolt tightening in order to meet the specified bolt load tolerances.
The intent of this Technical Specification is to ensure personnel are competent to assemble and tighten bolted
joints using the design bolt load and documented work instructions, thereby establishing a joint capable of
maintaining a leak-free status throughout its’ service life.
Competency in the analysis of joint failure is not required beyond use of knowledge gained during training. A
correctly assembled and tightened joint that fails in service requires specialist knowledge and is out with the
scope of this Technical Specification.
1.3 Validity
This Technical Specification is applicable for bolted joints included on mechanical equipment subject to the
PED, or any joint where failure would endanger personnel, plant or the environment. Such joints may or may
not be fitted with a gasket.
The validity includes all bolting arrangements, both circular and non-circular, and fluids (gas or liquid) with the
exception of:
? joints having less than 4 bolts, or bolt diameters less than M16;
? potable or fire water, sewage systems.
This Specification excludes:
? craft personnel who are trained, examined and verified as competent in their craft training or normal
course of work to assemble bolted joints, such as in the manufacture of equipment;
? professional persons, who by their professional training and experience and contemporary practices are
regularly concerned with bolted joints and their assembly.
1.4 Quality management system
Manufacturers or operators need to develop and include a procedural framework within their quality management
system to meet the requirements of this specification. Such a framework needs to address:
? identification of personnel requiring training;
? identification of a competent trainer or training provider, e.g. “Qualified Person for Pressure”;
? evaluation of the effectiveness of the training.
For examples, refer to EN ISO 9001:2000, 6.2.2.
BS DD CEN/TS 1591-4:2007 history
2013BS EN 1591-4:2013 Flanges and their joints. Qualification of personnel competency in the assembly of the bolted connections of critical service pressurized systems
2007BS DD CEN/TS 1591-4:2007 Flanges and their joints - Design rules for gasketed circular flange connections - Qualification of personnel competency in the assembly of bolted joints fitted to equipment subject to the Pressure Equipment Directive