Codprawn, you might be looking at this (POR15) for sealing your tanks.
The fuel Transfer hose uses a shreader valve and connects to your normal halfords charge up compressor (you know one of those that has a torch jump leads etc.) The reason most people have bought them is to carry additional fuel on board and be able to transfer to the main tank without the necessity to lift or move the jerry cans, as the hose is 10 feet long and has the normal gun trigger you get at the petrol station. My 'halfords' £39.00 air pump emties the cans in about 90 seconds.
Other people have bought them to refuel jet ski's and the 4 wheel guys for track days. The hand pump also empties in about 1 - 2 mins depending on your action!!
The Septer fast flow spouts are also very good as no glug glug as they have an air return. Unfortunatly quite expensive as I import from US.
At the end of the day horses for courses and all that.
Also if any of my products are bought and are unsuitable I give a 14 days full money back guarantee. Anyway if anyone wants any info just drop me a mail or post on here.