[Richard Farrant]

Originally Posted by Tony Smith

Richard's experience of the non-working extinguishers was a lucky one. The extinguishers were supposed to be emptied, cleaned and refilled every 12 months, as vapours off the sulphuric acid could corrode the copper internals, resulting in big green flakes of crud blocking the hose. If not cleaned out and left sitting for long periods, when activated the expanding Hydrogen gases would have no route of escape past the crud blockage and the cylinder would rupture explosively. The Cylinders were tested to 300psi.

Hi Tony,
I distinctly remember these old extinguishers were cream in colour, where they a foam type? Long time ago and they quickly disappeared after the incident and we had more user friendly ones. When the newer ones were due for a refill we used them on practice sessions.