@Crusty181, agree , I have said before, connect normal garden hose fitting to van mains inlet which usually runs thru the inside of van and somewhere underneath there is a PRV, which if the pressure ever gets that high will normally
(a)blow the hose fitting off the hose at tap,
(b) blow hose fitting off hose/van connection
(c) blow guest fitting off on inside of van at mains connection (unlikely if fitted properly)
(a)blow the hose fitting off the hose at tap,
(b) blow hose fitting off hose/van connection
(c) blow guest fitting off on inside of van at mains connection (unlikely if fitted properly)