PED is legislation : a kind of general articles and requirements concerning the european market, it contains some technical requirements but not enough to compare it to ASME B31.3. All recognized methods are acceptable by the PED including ASME B31.3. We had marked CE products done according to B31.3 and met the PED. You had only to conform to the requirements of the directive particularly Annex I (Essential Safety Requirements where they speak about material, design, manufacturing, control and inspection). The corresponding EN standard to B31.3 is EN13480 (Industrial piping) that are not yet adopted.