cylinder type tank conversion

[superkp]

hi
im looking at some stako underfloor cylinder type tanks for a camper conversion.
they look exactly like a car lpg tank but are red and very expensive.
as i understand these tanks are different as they supply gas vapours rather than liquid gas that needs hot water to vapourise.

is there a way to change the fittings on a car tank then use it for a camper?

[LPGC]

4 Hole tanks are either conventional with a liquid gas pickup tube going to the bottom of the tank to supply an engine with liquid gas, or are vapour take-off so have a pickup tube running to the top of the tank to pickup vapour to send to a conventional (cooking gas etc) type regulator. The tanks you pictured are 4 hole vapour tanks.

It is possible to adapt a conventional 4 hole tank to become a vapour take off tank - by removing the outlet valve and drilling a hole through the top of the internal pickup tube but care must be taken to mount the tank so that the drilled hole won't be covered with liquid gas... which leads to a compromised situation because the normal angle for mounting 4 hole tanks (correct for the 80% fill limiter etc) would see the drilled hole covered with liquid gas when the tank is full.

Instead of a 4 hole design tank it is possible to fit a multivalve tank and fit a vapour take-off multivalve instead of liquid take-off multivalve.

[superkp]

do you meen this type of tank?

[LPGC]

Yes but you would have to empty the tank if it contains any LPG and change the type of valve that's fitted to a vapour take-off valve.
Also bear in mind that the tank has to be mounted in a certain position so the valve is X degrees up from the horizontal (usually 30 degrees but vapour valves may be different).

[disco stu]

Are those red tanks normally composite type construction? Seem to have seen photos like that around. Just wondering if that explains the price

[LPGC]

They are usually steel.

4 Hole tanks are more expensive than single hole tanks even for 'normal' autogas use, then the price is probably inflated further because of the specialist design (the vapour take-off instead of liquid take-off). On a 4 hole tank it is the tank itself (as opposed to valves that are fitted) that make the difference between vapour take-off and liquid take-off. On a single hole tank it is the type of valve fitted that makes the difference between vapour take-off and liquid take-off.

[disco stu]

Cheers