Written Scheme of Examination (WSE) for Hyperbaric Test Vessels – Don’t Blow It!
What’s involved with a Written Scheme of Examination and why it is essential for your hyperbaric testing system.
The "Check-Up" Your Hyperbaric Needs
Let’s be honest: nobody wakes up in the morning excited about a Written Scheme of Examination (WSE). In the world of subsea engineering, an inspection schedule usually feels like that annoying dentist appointment you keep pushing back.
But here’s the thing: when you’re cranking a vessel up to 400+ bar, "it was fine yesterday" is a dangerous game. Whether you’re testing ROV sensors or high-voltage subsea connectors, your hyperbaric chamber is the unsung hero of your workshop. If you don’t want it to let you down when it counts, read on.
Here is how to keep it from becoming a high-pressure headache.
1. The Legal "Nudge" (PSSR 2000)
In the UK, we have the Pressure Systems Safety Regulations (PSSR). It’s not just a suggestion; it’s the law. If your system stores "relevant fluids" (like nitrogen or water we commonly deal with), you need a formal inspection plan which is referred to as a Written Scheme of Examination (WSE).
Think of it as the MOT for your system. If you don’t have a valid WSE, your insurance company will be the first to vanish if a seal fails or a bolt decides to head for the moon taking something or someone with it.
2. What are we actually looking for?
We aren't just kicking the tyres. A solid inspection schedule for subsea testing systems usually looks like this:
The Annual "Quick Look": An external visual check. Are the gauges calibrated? Is there any visible corrosion (“gingering”) creeping into the welds, threads or sealing surfaces?
The Deep Dive: This is the big one. We’re talking NDE (Non-Destructive Examination). This involves stripping the insulation, checking for cracks with dye-pens or ultrasonic testing, and ensuring the internal threads aren't fatigued from a thousand pressure cycles, carrying out a pressure test and dimensional inspections.
The "O-Ring" Obsession: In subsea work, a tiny bit of grit in a seal groove is the difference between a successful FAT (Factory Acceptance Test) and a flooded piece of kit, let’s keep them fresh and make sure we keep the water on the wet side.
3. Don’t Let Your Vessel "Red Card" Your Project
There is nothing worse than being three days away from delivery only to realise your certification expired last month or the 2 week lead time O-ring has just failed.
A proactive inspection schedule means you find the pitted flange or the weeping valve before it stops production. It keeps your engineers safe, your auditors happy, and your subsea gear performing exactly how it should when it finally hits the seabed.
4. Who counts as a Competent Person?
It’s not just someone who feels competent.
PSSR defines a Competent Person as someone with the knowledge and experience to properly assess the safety of a pressure system. In practice, that means someone who understands how and why vessels fail, what needs inspecting, and how often those checks should happen.
They’re the ones who write (or certify) the Written Scheme of Examination, deciding what parts of the system need attention, what inspection method makes sense (visual, NDT, etc.), and what might cause trouble down the line.
Basically — someone who’s seen enough tired seals, stretched threads, and mystery leaks to know what’s worth worrying about before you wind it up to 400 bar.
The Bottom Line
At J Pope Solutions, we’ve seen everything from pristine vessels to chambers that look like they were recovered from the Titanic. Regular inspections aren’t just about ticking a box—they’re about operational certainty.
Keep it clean, keep it checked, and keep it under pressure (the good kind).
For help setting up your own Written Scheme of Examination (WSE) or just want us to handle it to keep you safe, legal and operational, contact J Pope Solutions now.