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LPG vaporiser

Posted: Sat Feb 21, 2009 9:58 pm
by Brenner5
I've made a start on my LPG setup finally!!

Which bits go where from my vaporiser?

I can see where the gas pipe fits but I'm not sure which rubber pipe goes to which part?

also the wires, how should they be connected?

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The bottom pipe connector has 'GAS 2' stated and the above is 'GAS 1'
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Any idea what goes in the bottom hole? i don't have anything for that

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Re: LPG vaporiser

Posted: Sun Feb 22, 2009 2:24 pm
by Brianmoooore
LPG in is the threaded port on the solenoid/filter valve.
Gas out can be either of the two ports provided - one fitted with a hose connector, and the other blanked off. You can use either, whichever is more convenient,but there are two schools of thought as to whether to take the gas from the bottom or top.
Gas contains contaminants, known as heavy ends (tar like substance) which gets deposited in the vapouriser. One school of thought says take the gas from the top port, so that it isn't contaminated, and drain the heavy ends from the bottom plug at service time, and the other says take the gas from the bottom port, so that the heavy ends are constantly being removed with the gas.
The two swiveling plastic elbows are the coolant connections that tee off your heater pipes. It doesn't matter which way around they go, but try and position the vapouriser with some consideration for air to self bleed out of it.
The threaded hole on the back side of the vapouriser is normally left open to the atmosphere, but try to position things so that dirt doesn't get into it. If used on a turbo/super charged engine, this hole is fitted with a hose connected to the pressure pipe from the charger.
The two solenoid valves are connected in parallel, and in parallel with the solenoid valve on your tank.
One wire goes to earth and the other to the "gas on" output from your LPG controller.
It doesn't matter which way around the wires go on most solenoids, but a few have built in diodes. These will be marked with '+' and '-'.

Posted: Wed Mar 04, 2009 6:39 pm
by Brenner5
Thanks Brian!

I have got a mixer from Tinley tech, 36mm bore for about £35.

Now does the rubber pipe from the mixer go to the top of the vaporiser (gas 1 port) with the stepper in between?

I was also given a a Tee piece with the mixer (pic below), what is that for?

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Also, when the copper pipes enter the tank to connect to the multivalve, do i need to bend the pipes to create a curve or can i join them straight to the multivalve?

The middle hole in my tank (from underneath) is just under the multivalve so i was thinking of joining them straight up but all the pictures of multivales tanks i have seen always have a curved pipe joining them.

Re:

Posted: Wed Mar 04, 2009 7:07 pm
by johnlouis
rubber pipe goes from vaporiser to mixer via stepper, but try and get the stepper nearer to the mixer end to give better response times on the closed loop. That "T" looks like a power valve which you probably wont need with a stepper / leonardo etc...

You should try and have curves in the LPG pipe to allow it to flex a little, standards dictate a pigtail loop in places so if you are rear shunted it doesnt fracture (or so I have heard).

good luck,
- Alex

Re:

Posted: Wed Mar 04, 2009 7:54 pm
by Brianmoooore
Pigtail loops at the end of the copper pipes also make it easier to disconnect them and reconnect, should the need ever arise.
Loops may or may not help preserve the integrity of the pipe in a shunt, but that's irrelevant, since the solenoid valve on the tank outlet will shut off the gas as soon as the solenoid loses power when the engine stops, or possibly sooner if the wires are damaged. Much safer than any petrol system!
You won't need the 'power valve' tee in the final set up if you have a stepper, but if you adjust the vapouriser and power valve for correct running, with the valve in place instead of the stepper, the vapouriser will be set up perfectly for when you put the stepper back in place, and, if you put the 'power valve' in the glove box, you will have all you need to "get you home" in the unlikely event of the failure of the gas ECU, etc.