I have had a look over a few web sites, came across this
Why do dry/wet risers need to be serviced?
• risers are prone to neglect and vandalism
• severe penalties should the rising main fail to work for the Fire
Service
• leaking from a wet riser could cause substantial damage
BS 5306 Part 1 1976 recommends for dry risers:
• a visual inspection every six months
• an annual pressure test
BS 5306 Part 1 1976 recommends for wet risers:
• 2 visual inspection services per year
• 2 electric pump inspection services per year
There are a couple of things there - Severe penalties should the rising main fail to work for the fire brigade. I guess that the company will be pursued (if things go wrong) and you being the only person unqualified to use it will then be pursued for any liability.
• leaking from a wet riser could cause substantial damage - I know that you are looking to use a dry riser but when it is charged and you have a problem, connecting, whatever, there is the potential of creating scenes from Noahs Ark, maybe there is a problem below you, a seal gone, no problem on your floor but because you have charged the system things are bobbing about.
They are for fire brigade use, you don't know what you are doing with the system, will have reason to poo your pants if it goes wrong. I would leave alone and look at alternatives.
I went to have a look at cleaning a car park in Birmingham airport, 8 storeys high, needed to get water up there, tank driven up, lots of 11/4 inch hose and a fire hydrant set up.
If there was no fire hydrant then we would have used a tank at bottom, tank at top and a very big pump to pump between the two.
There will always be another way
Rob