PD 5500:2024+A3:2026 is the latest amendment to the UK's unfired pressure vessels code. It specifies requirements for the design, construction, inspection, testing and verification of compliance of new unfired pressure vessels.
The code supports the safe and cost-effective design, manufacture, and inspection of pressure vessels made from carbon, ferritic alloy and austenitic steels. It also includes requirements for vessels manufactured from materials including aluminium, copper, nickel, titanium and duplex materials.
Amendment 3 is the third and final update to the current 2024 edition and introduces technical improvements, clarifications, corrections, and new guidance for pressure vessels used in hydrogen service.
PD 5500 is designed for organizations and professionals involved in pressure vessel specification, design, manufacture, inspection and operation, including:
It's particularly relevant for organizations supporting the UK's growing energy infrastructure and nuclear new build programme.
PD 5500:2024+A3:2026 provides comprehensive requirements and technical guidance covering:
The code brings all essential requirements into a single authoritative document.
Using PD 5500:2024+A3:2026 helps you:
For organizations involved in the UK's nuclear new build programme, PD 5500 provides a recognized framework for designing and delivering the pressure vessels required across new nuclear facilities.
PD 5500:2024+A3:2026 is the latest amendment and introduces technical and editorial updates designed to improve accuracy, clarity and usability, including:
New hydrogen service guidance
A new Enquiry Case, EC148, provides additional recommendations for pressure vessels used in hydrogen service. This new content highlights:
These changes help users apply the code more consistently while supporting emerging energy technologies.
As the UK advances its nuclear new build programme, the demand for pressure-retaining equipment continues to grow. Pressure vessels play a critical role throughout nuclear facilities, from reactor support systems to cooling, waste management and process applications. PD 5500 provides recognised guidance for the design and manufacture of unfired pressure vessels used in the non-nuclear parts of nuclear power stations, helping organizations ensure safety, quality and operational reliability. With new nuclear facilities being built, extended and retained to support the UK's energy security and net-zero ambitions, the need for pressure vessel expertise and trusted standards such as PD 5500 is becoming increasingly important across the nuclear supply chain.