I am looking at a premises which has 6 falling foam systems via three inlet boxes. The routes from the inlets to the protected rooms are long and two of them go 4 floors below ground level. The systems are 'tested' via a visual inspection (of the bits that can be seen) every year and there's an audit trail going back at least 10 years. All in all, I should be happy as it would pass most audits.
However, next year the installation will be 30 years old. I understand that none of the systems have ever been used in anger, so in three decades these steel pipes, fixings and connectors have sat there passively doing nothing. I accept that there would be only minimal pressures involved if charging any of the systems (compared with a DRM), but how confident can I be that 30 years of corrosion, being subject to vibrations in plant areas they run through, and after 30 years of building changes - the systems will deliver the bubbly stuff to where it is needed?
I would also like to confirm that each of the inlets actually discharge in the spaces where the labels say they will.
I do not believe that the fire service would be able to access the rooms 4 floors down without the help of the foam suppression systems - even then it would be a struggle - so I believe the system needs to be perhaps more resilient than the current BS testing provides for.
So I am intending to blank off each outlet in turn with polythene, tape and cable ties and fill the pipework with compressed air through a gauge. Then leave it for a moment (a minute?) to see if here is any significant pressure loss. I will also be able to confirm the inlets tie up with the right outlets.
We may struggle to get a tight seal at first, but can anyone see any other pitfalls with my ad hoc system, or better still, has anyone every carried out this sort of one-off test before?
Alternatively, (as Mrs Messy will often say) am I worrying too much?
Thanks