Ten Questions to Ask Before You Specify a Hydrogen Pipework System
Hydrogen projects in the UK are moving from ambition to construction at pace. The UK government's pipeline already includes more than 250 potential low carbon hydrogen production projects (DESNZ, 2024). Every one of them needs pipework, valves and flow control. And almost every project that runs into trouble does so for the same reason: the duty was not properly defined before selection began.
Here are ten questions worth asking before any thermoplastic or flow control specification is written.
1. What is the complete media composition?
Not just 'hydrogen'. What is the actual concentration, and does it vary across operating modes? Are moisture, compressor oils, nitrogen or other gases present? What happens during purge, test and fault conditions? A material or seal selected against 'hydrogen' alone may not perform adequately against the complete profile.
2. Have you defined pressure properly?
One pressure figure is not enough. Minimum, normal, maximum and design pressure all need to be recorded, each with a stated basis (gauge or absolute). Add test pressure, transient conditions and cycle frequency. Never review a pressure rating without knowing the temperature it applies to.
3. What is the full temperature range, including the environment?
Process temperature and ambient temperature both matter. Cold starts, rapid depressurisation, nearby heat sources and outdoor exposure can each create conditions outside the normal operating range. Review the most demanding combination of pressure and temperature, not only the design maximum.
4. How often does the system cycle?
Continuous operation and frequent start-stop cycling create very different fatigue profiles. Two systems can share the same headline pressure and temperature rating yet experience entirely different operating stresses. Cycle frequency, ramp rate and design life in operating cycles all need to be defined.
5. Have you reviewed every element of the wetted path?
The pipe material is only one part of the system. Valve seats, stem seals, O-rings, flange gaskets, instrument connections, thread sealants and flexible connections all require the same duty review. For valves, define the function, cycle frequency, leakage class, fail position and applicable hazardous area requirements. Do not assume that all components within a nominally matched system share identical ratings or seal grades.
For process-critical valve duties involving corrosive or aggressive co-media, SwissFluid fully lined valves offer TA-Luft and ISO 15848-1 compliant performance with traceable documentation. Where sampling or instrumentation connections are needed, SERTO precision compression fittings provide controlled, repeatable joints.
6. Is gas purity a requirement?
Compatibility and cleanliness are separate questions. A component may be chemically compatible with hydrogen yet shed particles, introduce extractables or carry residues from cleaning that compromise downstream fuel cells, electrolysers or analytical equipment. Confirm both, and define the evidence required at handover.
7. What is the jointing method, and can it be executed on site?
For thermoplastic systems, butt fusion, electrofusion and socket fusion each require calibrated equipment, controlled parameters, trained operators and recorded results. Jointing decisions left to site create uncontrolled variables. IPS supports fusion jointing with equipment, guidance and training.
For PE100 large-diameter duties, AGRU systems including AGRU XL pipework carry established credentials across industrial and energy applications. Where stainless press fit systems suit the installation, RM Press-Fit provides a reliable, tool-controlled option for building services and compressed air duties.
8. Does the specification cover abnormal and temporary conditions?
The most demanding duty is often not normal operation. First pressurisation, emergency shutdown, purge and blowdown, and test conditions can each create pressures, temperatures or media exposures outside the normal range. Review the system beyond its most convenient scenario.
9. Are hazardous area requirements assigned and documented?
Hydrogen's properties can lead to higher-grade hazardous zones for a given release scenario than many other gases. Area classification, ventilation design, ignition control strategy and gas detection all need to be integrated into system design before procurement, not added afterwards.
10. Is the documentation plan agreed?
Traceability, jointing records, inspection results and commissioning evidence need to be captured as work progresses, not assembled retrospectively at handover. A well-documented hydrogen system is safer, easier to maintain and more straightforward to modify.
IPS Flow Systems supports consulting and specifying engineers on hydrogen and new energy projects with technical knowledge, manufacturer-backed data sheets and practical guidance from duty definition through to installation. With over 30 years in specialist thermoplastic piping and next-day delivery from large UK stocks, IPS is a single accountable partner from specification to commissioning.
If you are approaching a hydrogen pipework specification and want to work through the duty conditions before selecting materials, book a call with one of our sales engineers today.
