What is PD 5500:2021 about?

This is the new edition of PD 5500, the UK’s national pressure vessels code. This edition marks the start of a new three-year publishing cycle in which an amendment will be produced each September:

- Amendment 1 is planned for September 2021

- Amendment 2 will come out in September 2022

- The final amendment, Amendment 3, will be published in September 2023

Those who buy PD 5500:2021 will receive the upcoming three amendments as part of their subscription to the new edition, which also brings together and repackages all of the content released during the last three-year cycle.

Who is PD 5500:2021 for?

Organizations that commission, design, build, inspect and test pressure vessels. It will be used by:

Mechanical engineers
Pressure vessel designers and design consultancies
Pressure vessel manufacturers
Pressure vessel inspection bodies in the oil and gas, petrochemicals, process plant and energy generation (including nuclear) industries

Why should you use PD 5500:2021?

This is an invaluable reference tool for the safe and cost-effective design and assessment of pressure vessels. It specifies requirements for the design, manufacture, inspection and testing of unfired pressure vessels made from carbon, ferritic alloy, and austenitic steels. It also includes material supplements containing requirements for vessels made from aluminium, copper, nickel, titanium and duplex.

PD 5500:2021 also helps users enter new markets, trade more seamlessly, increase trust in their products and manage risk more efficiently.

What’s new about PD 5500:2021?

The new edition of PD 5500 brings together all of the changes and enhancements introduced during the 2018 publishing cycle. The main changes in PD 5500:2021 are therefore:

a) Updating of various internal and external references

b) A new enquiry case for cylindrical shells of varying thickness under external pressure

c) Requirements for load combinations on pressure vessels

d) Additional requirements for flanges with swing bolts or clamp bolts

e) Requirements for permanent joints other than welding

f) Clarification of the limits for longitudinal compressive stress in Annex A

g) Clarification of the calculations for circumferential stresses in horizontal vessels on saddle supports

h) Revisions to the worked examples in Annex W in line with the amendments to the calculations in Annex G

i) Revisions to the clause references in Annex Z

j) Revisions to the permitted material groups in Table Al.3.4-1

k) Clarification of the requirements for welder and operator approval in the duplex supplement

As well as all of the above technical changes, the usual clarifications and corrections – including to some of the figures – were incorporated into the code to ensure and enhance its accuracy and usability.

PD 5500:2021 PDF

Specification for unfired pressure vessels

Published:

31 Jan 2021

Withdrawn:

27 Sep 2021