Safely disconnect gasit lpg tank [solved - smell coming from leisure battery]

[timski]

Update: Turns out it was the leisure battery!? I found it by chance. The battery is warm and giving off an awful smell. I had been trickle charging it through my 240 hookup at home. I disconnected it a few hours back when I had the whiff of gas and assumed it was the lpg. I left all the doors open to air it. Then I followed my nose as it appeared to be near the passenger seat and then I noticed it. Moving some questions from previous E D I T to new post as they relate to the leisure battery not the gas tank.
============
Hi All,

Can anyone remind me how to safely disconnect the Gasit LPG tank? I had to disconnect it when some welding was done on the van, so I disconnected it and then took  it to get it reconnected and serviced at the same time at Campershack. I've got a whiff of gas and I'm sure it's not the calor gas as I've removed the bottle, so I'd like to disconnect it and book it in for an LPG service. 

Thanks,
Tim. 

[Mocki]

Let me understand this .....
you want to take the tank out ? 

the tank is disconnected as soon as you turn the power off to the lpg system , the solenoid switches off the supply at the tank 

I suggest you dissolve a pea sized blob of washing up liquid in a half litre of water and find a soft brush and brush the solution around all the pipe unions with the lpg system turned on , any leak will blow bubbles 

be sure to wash all 0laces you test with clean water after 

[timski]

Thanks Mocki, I didn't notice your reply till I had made an update. Turns out the smell was coming from the leisure battery! <facepalm>. After ventilating the van well I had done a check with soapy water on all the joints I could get to and found nothing. Then I noticed the leisure battery. Anyway, it's given me the kick up the backside to make sure I get it booked in for it's LPG service. It's overdue as I used to take it to Camper Shack and he's moved up to Scotland (bit too far although I'd be tempted, Andy was fab) and I've moved to Salisbury and I hadn't found a garage that does LPG services near me yet. I've located a few now (one in Poole, one in London) so I'll try to get it booked in on Monday.