Are you looking for a template for a technical file?
First it depends on how you are planning on CE marking the part - is it self declared or do you need a notified body's design review and approval?
There are a lot of different levels in the PED for different devices and pressure ratings.
The Directive tells you exactly what you need in your technical file, the hard part is usually determining what part of Article 3 applies so you can apply the correct Annex.
I would suggest you contact a Notified Body for consultation. Even if you self declare you need to comply with the quality system requirements of the PED and the requirements of Article 3 Paragraph 3.