The Directive does not require for qualification of forming procedures in section 3.1.1 of Annex I, although it includes such a qualification for permanent joints in section 3.1.2 of Annex I.
But there is an essential requirement about the preparation of the component parts (cf Annex I, point 3.1.1) and the manufacturer shall demonstrate in the technical documentation of the equipment that this requirement has been satisfied.
Depending on the modules, the Notified Body may examine this technical documentation.