DS CEN/TS 1591-4:2007

Flanges and their joints - Design rules for gasketed circular flange connections - Part 4: Qualification of personnel competency in the assembly of bolted joints fitted to equipment subject to the Pressure Equipment Directive

Scope

1.1 General
This European Technical Specification establishes a process for training and competency assessment of per-sonnel who disassemble, assemble and tighten bolted joints such as fitted to equipment subject to the Pres-sure 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 guar-antor 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 con-trolled 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 nor