Sch 1A para 4 UK marking and declaration of conformity
The manufacturer shall— (a) affix the UK marking to each individual piece of pressure equipment, or assembly, that satisfies the applicable requirements of these Regulations; (b) draw up a written declaration of conformity for the pressure equipment, or assembly, which identifies the pressure equipment, or assembly, for which it has been drawn up; (c) make a copy of the declaration of conformity available, to the relevant authorities, on request; and (d) keep a copy of the declaration of conformity at the disposal of the national authorities for 10 years after the pressure equipment, or assembly, has been placed on the market.