Pressure Vessel Codes used in the UK

There are several codes and standards that are used to regulate the design, construction and use of pressure vessels in the UK. They govern the safety requirements, standardisation of manufacturing, and maintenance of all types of pressure vessels in the UK. Some of them cover wider regions including the EU, USA and some just the UK itself.

In this post, we will explain the main pressure vessel codes used in the UK, and what they cover. Here at Vessco Engineering, we follow all these regulations with precision at all stage of our processes.

Pressure Equipment Directive (PED)

The Pressure Equipment Directive is a European Union regulation that laid out the safety requirements that all pressure equipment must conform to. The UK has left the EU and the transition period ended on 31st December 2020. Accordingly, UK is no longer following the PED for vessels destined for the UK market, but UK manufacturers producing for EU markets still follow the Directive. Since January 2021 pressure equipment for the UK market must conform to the Pressure Equipment (Safety) Regulations 2016. It has been legislated by the UK government and is a legal requirement. These Regulations cover design, manufacture and conformity assessment for pressure equipment and assemblies with a maximum allowable pressure PS above 0.5 bar. According to the directive, pressure equipment includes vessels, piping, safety accessories and pressure accessories. Prior to the end of 2020 pressure vessels for use in the UK were CE marked; the CE mark has since been replaced with United Kingdom Conformity assessment (UKCA) marking.

It applies to importers, manufacturers, and distributors.

Health and Safety Executive (HSE) Guidelines

Covering European and British standards, these HSE guidelines for pressure vessel use and operation are essential for ensuring that pressure vessels are used safely at all times. It is a legal requirement to follow these standards. It prevents operators from life threatening or life limiting injury by preventing system and component failure, and associated hazards. The PE(S)R ensure pressure equipment is:

  • Safe
  • Meets essential safety requirements
  • Carries the UKCA marking (or until 31 Dec 2022, the CE mark)
  • Correctly labelled (manufacturer’s name, type, batch or serial no.)
  • Provided with adequate instructions and safety information

BS EN 13445

Published by the British Standards Institution, the BS EN 13445 is one of the most important standards for the design and manufacture of pressure vessels, covering materials and components used, manufacturing methods, and the way vessels are designed. EN13445 was developed to be a pan European code for pressure vessels for use primarily within the EU. The BS EN13445 code is still very much in use in the UK, even though the PED no longer applies.

It applies to unfired pressure vessels that are under pressure greater than 0.5 bar gauge, but can also be used for lower pressures, as well as vacuum. It is referred to during inspection, testing, and all aspects of manufacturing and construction processes.

ASME Boiler and Pressure Vessel Code

The ASME code is often used within in the UK and indeed it is used throughout the world to ensure the safety and reliability of pressure vessels, including boilers. It was created by the American Society of Mechanical Engineers and is one of the most widely used codes.

It is referred to in all aspects of design, building, inspection, testing and certification of equipment including power plant components, domestic and commercial boilers, and all types of pressure vessel and their parts and fittings.

PD5500:2024 Code

PD5500 is a popular pressure vessel code which has its roots in UK engineering history. Its predecessor BS 5500 was first issued in 1976 and itself was derived from earlier codes such as BS1500 and BS1515. Vessco Engineering use PD5500 these days for approximately 10% of the vessels designed for the UK market.

Other Codes

PD5500, EN13445 and ASME VIII Div. 1 are the most commonly used pressure vessel codes used in the UK today. There are however many other codes available such as ASME VIII Div. 2 and Div.3 which are generally used for thick walled pressure vessels. As with PD5500 many other European nations have their own pressure vessel codes which were in place before the introduction of EN 13445. Examples include Stoomwezen in Netherlands, CODAP in France and A D Merkblatt in Germany. Vessco Engineering have experience of these codes, a current example includes the manufacture of a large deaerator vessel for Hinkley Point C nuclear power station, which was designed by Alstom in France using CODAP.

Vessco Engineering uses all the above codes and regulations to ensure all pressure vessel manufacturing processes are fully compliant and safe, from design and development, through to fabrication and testing. To see our full range of services, please click here.