Hooking up Twin LPG tanks into one line ? Help Please :)

[Mulisha]

hi guys

I have a SWB Patrol and i have one 90L usable LPG tank and i have another 60L usable gas tank that i need to hook up to the line going to my converter.


Is this hard to becuase i wanted to do it myself if possible and just but the bits from somewere.. (is there a online shop that sells LPG gear)?

I want to keep the 60L tank as researve if possible making it my find a servo tank.


Could someone explain what i should do or what i need and were i can buy all this stuff from a Australian ONline store would be good if possible..

Cheers

Rick.

[mattsluxtruck]

You will need to fit a hydro static valve on the supply line by law. This draws off both tanks equally but with some wiring mods to the solenoids you could only run one tank at a time. It will just be a T piece on the fill line cause the afl just locks off the tank when its full and the other tank keeps filling until the afl locks off on that. I had two different size tanks in my old lux and this is how it worked. I just drew off both tanks equally the only drama was my fuel guage was only connected to the smallest tank from memory.

[Mulisha]

You will need to fit a hydro static valve on the supply line by law. This draws off both tanks equally but with some wiring mods to the solenoids you could only run one tank at a time. It will just be a T piece on the fill line cause the afl just locks off the tank when its full and the other tank keeps filling until the afl locks off on that. I had two different size tanks in my old lux and this is how it worked. I just drew off both tanks equally the only drama was my fuel guage was only connected to the smallest tank from memory.

oh ok

So i can't allow my car to suck away all the fuel from my 90L tank and leave my 60L tank full untill i switch it over when needed?

Were can i get all this stuff and can i fit it myself?

Thanks alot

Rick.

[PGS 4WD]

Is this car modifeid for performance? Hydrostatic "T" connectors are restrictive and can cause fuel supply issues, especially with high power turbos.
You want to avoid a lean situation at all costs.

Joel

[Mulisha]

Is this car modifeid for performance? Hydrostatic "T" connectors are restrictive and can cause fuel supply issues, especially with high power turbos.
You want to avoid a lean situation at all costs.

Joel

Yes my car does have a Turbo and u had posted in the thread a few times...


Would u mind recommending what i need to get then please for what set up i'm trying to achieve.


Rick.

[Mulisha]

I been thinking but there is a Solinoide on my gas tank isn't there?

Couldn't i put a T piece in my feed line to my conveter?

And put a T piece in my filling line?

I have a switch already in my car from changing to petrol to gas so i should be able to use that or something?


Will this work though or am i missing something could someone explain the way

Cheers

Rick.

[mattsluxtruck]

Yes you could make it work with T pieces and switching the solenoids very easily , but its the legalities that are an issue. Ill send you a PM tomorrow on how you could make it work illegally if you choose to do it that way its your call...................... V8 patrol is the gas legend around here it might pay to see what he thinks too.

[TEAMRPM]

I been thinking but there is a Solinoide on my gas tank isn't there?

Couldn't i put a T piece in my feed line to my conveter?

And put a T piece in my filling line?

I have a switch already in my car from changing to petrol to gas so i should be able to use that or something?


Will this work though or am i missing something could someone explain the way

Cheers

Rick.

Mate id leave to someone who knows what they are doing because if you dont flare your fittings properly you can cause some serious damage to your car, your self and others . take it into you nearest LPG fitter and tell them what you want, imsure it will be of a minimul cost apart from the hydrostatic valve that is, there dear lil buggers.
somethings really should be left alone!..

[Mulisha]

Thanks guys

I'll see how i go tommorow.

Rick.

[Loanrangie]

You will need to fit a hydro static valve on the supply line by law. This draws off both tanks equally but with some wiring mods to the solenoids you could only run one tank at a time. It will just be a T piece on the fill line cause the afl just locks off the tank when its full and the other tank keeps filling until the afl locks off on that. I had two different size tanks in my old lux and this is how it worked. I just drew off both tanks equally the only drama was my fuel guage was only connected to the smallest tank from memory.

oh ok

So i can't allow my car to suck away all the fuel from my 90L tank and leave my 60L tank full untill i switch it over when needed?

Were can i get all this stuff and can i fit it myself?

Thanks alot

Rick.

This is easy to achieve, as said previously you need a hydrostatic valve to connect the 2 tanks to the single inlet line to the converter. To be able to switch between tanks all you need is to run the power leads of the tank lockoffs up to the dash and wire to a simple 2/3 position switch (either tank1/tank2 or T1/off/T2) and run the power lead from the controller (should be labelled tank) to the switch.

[Mulisha]

Thanks mate for that

But someone said above that the hrdostatic valve will lean my car out ? My has a turbo and has been dyno'd etc so i'm not real keen on leaning it out.

Thanks

Rick.

[V8Patrol]

This is easy to achieve, as said previously you need a hydrostatic valve to connect the 2 tanks to the single inlet line to the converter.
To be able to switch between tanks all you need is to run the power leads of the tank lockoffs up to the dash and wire to a simple 2/3 position switch (either tank1/tank2 or T1/off/T2) and run the power lead from the controller (should be labelled tank) to the switch.

On the $$$$$$$$$$$


The hydrostatic valve is a MUST HAVE ITEM for legal reasons ( only )

A tee piece will work ....... BUT .......

one tank is empty and you switch to reserve, the car continues on, LPG will go from ya reserve tank to the converter AND it will start to back fill ya main tank !!!
Tank lockout valves only work in a one-way direction, they stop LPG from exiting the tank, they dont stop LPG from comming in via the supply line !

So what you'll have is a situation where ya main tank will have about 1/2 of what the reserve tank held once ya flicked across to the reserve.....
even switching back n forth between tanks will always see whatever the amount of LPG is in the reserve tank will be halved into the main tank.

To put it simply....... the two tanks WILL want to equal out pressure wise the instant you connect them by opening that reserve tank lockout.
A oneway valve installed in the supply line from the main tank will stop that from happening.

The hydrostatic valve also prevents this from happening too......


So now ya have a choice of fitting a tee piece & oneway valve (with legal issues) or the correct part.



Kingy

[Deleted User]

Any Gas questions, pm Viet667 -- he`s the expert. ( no offence to others )





.

[Mulisha]

Thanks alot guys I'll see what prices i get from some LPG joints and stuff..

[viet667]

Thanks gatta, I don't claim to be an expert in LPG even though I have been involved in the gas industry for 20+ yrs. There always seems to be new unsolved problems cropping up. What the other guys mentioned has just about covered all the facts with hooking up twin tanks.
With the leanout issue I asked some LPG fitters today to see if they have heard of problems. One said that there could be a problem when one tank runs out and the other one takes over. That reminded me when I borrowed a mates F100 to tow a caravan, it had twin tanks and while going up a hill one tank ran out. It ran with no power for 30 sec until the other tank kicked in. This must have been due to the vapour in the "empty" tank still having more pressure than the second full tank. Pressure in LPG cylinders is all temperature related, not how much is in them. The hottest one empties first, provided they are both turned on.
So I guess a lean off period can occur during automatic switching, maybe not if you manually switch over before one tank gets to the vapour stage.

[Mulisha]

Thanks gatta, I don't claim to be an expert in LPG even though I have been involved in the gas industry for 20+ yrs. There always seems to be new unsolved problems cropping up. What the other guys mentioned has just about covered all the facts with hooking up twin tanks.
With the leanout issue I asked some LPG fitters today to see if they have heard of problems. One said that there could be a problem when one tank runs out and the other one takes over. That reminded me when I borrowed a mates F100 to tow a caravan, it had twin tanks and while going up a hill one tank ran out. It ran with no power for 30 sec until the other tank kicked in. This must have been due to the vapour in the "empty" tank still having more pressure than the second full tank. Pressure in LPG cylinders is all temperature related, not how much is in them. The hottest one empties first, provided they are both turned on.
So I guess a lean off period can occur during automatic switching, maybe not if you manually switch over before one tank gets to the vapour stage.

Thanks alot for that mate.


I went to a LPG place yesterday and when i took the second tank there to see what he thinking of installing it etc and he said the "Sirtek" multi valve needs to be replaced becasue they blow up or something


I personally do think it will be that hard to hook up the second tank once i get all the bits but the guy yesterday was saying with you supplying the tank ur looking $1000 or so... I kinda left after that becuase he seemed to be a little werid when i was saying a few things about the hydrostatic valve etc.

He said fittings are around $15ea and the gas line is $12 a meter.


I was thinking of hooking everything up doing all the work then gettting a LPG joint to have a look over everything make sure it's all fine in what i did and i would be ok.


I need to get the tank i want to use as my second re tested and unsure if that valve really does need replacing.

But thanks heaps i'll ring another place this afternoon and see how i go there.

He also said i couldn't use a forklift bottle becuase there removable and ur not allowed to make up brackets to hold the gas tanks themself as it's against the law ...

Rick.

[viet667]

Sidek multivalves certainly don't blow up. With most multivalve tanks when they need retesting , the entire valve is replaced due to the fact that the relief valve can't be serviced. There are a couple of exceptions with some multivales having a removable relief valve.

Check the date on your tank to make sure it does need retesting, you have 10 yrs from the stamped date.

For high performance use, multivalves tend to flow a lot less than a 4 valve tank like APA or MANCHESTER, although sidek is one of the better ones. Most have very small diameter dip tubes designed for the European market.

Forklift bottles are legal if they are fitted with AFL vales, (fill limiters) but the brackets that hold them in place must be permanant and not removable. Brackets are supposed to have engineers reports for them, which most manufacturers have but I still see a lot of home made lookng brackets being sold.

PM for prices , I sell and carry most LPG fittings and parts.

[juls]

I have a v8 patrol on gas with a 85lt cylinder where the tank used to be.

Since this is only 65lt usable its pretty useless for range so Im looking at fitting another tank too, and an auxillary petrol tank.

What I was pondering is replacing the 85lt cylinder with two 600-650mm long cylinders running lenghtways where the fuel tank used to be. The APA catalog shows something like a D62 which is 620 x 432mm diam.

This way I can use the space next to the driveshaft to fit an auxillary fuel tank.. As apposed to a mid mounted LPG cylinder plus the rear cylinder and fuel tank. Should give 120l gas and 40 or 60 petrol.

Is there any problem with running the LPG cylinder lengthways?

[460cixy]

I personally do think it will be that hard to hook up the second tank once i get all the bits but the guy yesterday was saying with you supplying the tank ur looking $1000 or so... I kinda left after that becuase he seemed to be a little werid when i was saying a few things about the hydrostatic valve etc

that seems prety farkin expencive

[Mulisha]

I personally do think it will be that hard to hook up the second tank once i get all the bits but the guy yesterday was saying with you supplying the tank ur looking $1000 or so... I kinda left after that becuase he seemed to be a little werid when i was saying a few things about the hydrostatic valve etc

that seems prety farkin expencive

Tell me about it !

I think i'll PM Viet later tonight maybe or something and get some prices on a few things i just have no idea what fitting i'll need really..

And somewere above someone said that with the fitting they need be flared or something

I thought i just cut the gas hose to the right length then say fit the T piece and attach the fitting tothe hose i cut ?

Or is there a different way to connect these fittings..

Also i might go to the wrecker and see what gas tanks they have there that are in date.

Yeah anyway

Thanks heaps

Rick.

[460cixy]

i wouldent fuck around with the copper line. get the flexable shit and fittings. its easyer but more expencive. well it was last time i converted my paj. i will be doing guy from no wheres 60 with twin tanks and definitly wont be useing copper. i tryed to order a hydrostatic valve throu work today (ford) as the ba utes with twin tanks have them but there not lised in spares so i need to look else where hardest part around here is wankers that wont sell the parts because they think there protecting you from blowing your self up. yet all the shits available on the net no questions asked

[Mulisha]

i wouldent ***** around with the copper line. get the flexable shit and fittings. its easyer but more expencive. well it was last time i converted my paj. i will be doing guy from no wheres 60 with twin tanks and definitly wont be useing copper. i tryed to order a hydrostatic valve throu work today (ford) as the ba utes with twin tanks have them but there not lised in spares so i need to look else where hardest part around here is wankers that wont sell the parts because they think there protecting you from blowing your self up. yet all the shits available on the net no questions asked

Thanks mate.

So i have to flare the fittings ot what every is only for copper line?

I was going to use the flexi stuff for sure!


With the flexi line and adding the fittings to it etc is it like putting fittings in heater hose just push the end of the fitting inside the pipe oe does the fittings and hoses work different and can someone at home do themself?


I'm glad this forum is here becuase if i was to ask these questions at a LPG place they wouldn't even answer them they just would wither say it's to hard or they have to do it.


Thanks alot Rick

[Shadow]

i wouldent ***** around with the copper line. get the flexable shit and fittings. its easyer but more expencive. well it was last time i converted my paj. i will be doing guy from no wheres 60 with twin tanks and definitly wont be useing copper. i tryed to order a hydrostatic valve throu work today (ford) as the ba utes with twin tanks have them but there not lised in spares so i need to look else where hardest part around here is wankers that wont sell the parts because they think there protecting you from blowing your self up. yet all the shits available on the net no questions asked

Thanks mate.

So i have to flare the fittings ot what every is only for copper line?

I was going to use the flexi stuff for sure!


With the flexi line and adding the fittings to it etc is it like putting fittings in heater hose just push the end of the fitting inside the pipe oe does the fittings and hoses work different and can someone at home do themself?


I'm glad this forum is here becuase if i was to ask these questions at a LPG place they wouldn't even answer them they just would wither say it's to hard or they have to do it.


Thanks alot Rick

Unfortunately they take this stance because there are so so many dodgy gas installs getting around the place and the only way to stop it happening, is to stop every unqualified person from doing it, not just the dodgy/lazy ones.

you flare copper pipe, no idea how the flexi stuff works but you cant flare it .

[PGS 4WD]

I spent a lot of time with high powered LPG vehicle in my 10 years with Gasresearch, 10 second quarter mile VL's and I6 Turbo falcons. The maximum power I've seen and acheived is 375 rw kW. The LPG supply must keep up or the engine will lean out and fail, I saw a $3500 pair of alloy heads burn from chamber to chamber on a vehicle due to the operation of the excess flow valve. As a safe guide I have found 1 line and 1 converter up to 160 rw Kw, 2 converters 1 line ans 2 lockoffs, up to 180 rw kw. Beyond requires 2 lines two converters, if you are buying new tanks you can get from APA duel outlets.
You must ensure sufficient gas flow to stop the engine leaning out how you go about this is up to you.
I have had to port and modify tank valves for flow, no one considers a big petrol pump to be strange but no one considers gas supply.

V8 Patrol is 100% correct in the behaviour of the fluid between tanks, lock offs only stop flow one way. The tanks pressures will equalize, the levels won't, due to different temperatures the tanks are subjected to one will tend to empty first(under car in car, nearer exhaust) as the pressures equalize they take fluid along for the ride.
Dynotuning is a great tool but we found as we couldnt accelerate the dyno as fast as we can on the road in say 2nd gear, fluid moves in mysterious ways, it resists change, when you accelerate a powerful engine rapidly, the pressure in the converter and lines drops substantially, this can cause the excess flow valve to trip and the vehicle to lean out as the tank pressure is now higher than the line pressure. It is quite possible that the problem may not present on a dyno. Things to look far are ramping the vehicle slow and fast on the dyno and looking for a difference in the mixture data log, if you find the mixture is noticably leaner on a fast acceleration ramp you have a problem. Considering the faster the vehicle accelerates the bigger the problem, turbos exihibit this more as they have such pronounced increases in torque over a very small number of engine revolutions. A turbo engine can be making 50 kw at 3000 rpm and 350 kw at 3500 rpm with a large roller turbo, the fuel demand is huge and rapid compared to a naturally aspirated engine.
I have seen first hand the consequences of messing this up, holed pistons, bent rods, failed head gaskets and so on.

Multiple line and converters help as the pressure drop is less due to the larger amount of reserve on the engine side of the restriction be what ever that is, excess flow valve or hydrostatic.

If you have a good tuner and the time you could put pressure gauges on the converter primaries, ensure the primary pressure is equal to the normal at rest primary pressure plus boost pressure under boost. If the primary side of the converter pressure drops below STD + Boost while under boost pressure then you have a supply issue, the line pressure is dropping due to a restriction.

I know this dosent give you the answer to your problem and I cant advise you to do anything that is not leagle, bearing in mind, excess flow valves pre date tank lock offs. Should you crash and the line sever, then the engine will stall and the safety switch will shut the solenoid. Also if the line is cut the likely hood is the power to the rear tank solenoid will also be as most people run the power down the gas line.

Hope this helps

Hope this helps.

[Mulisha]

What i might do is sort out what i need like fittings and valve and get the tank etc ...



Then mount the tank in the car then get a gas shop to hook up all the lines.

I'm not going to bo it dodgy i like to do it right the first time.


I'm just annoyed that i can get a tank to mount under the side of my car under the drivers seat.

Cheers

Rick.

[juls]

I personally do think it will be that hard to hook up the second tank once i get all the bits but the guy yesterday was saying with you supplying the tank ur looking $1000 or so... I kinda left after that becuase he seemed to be a little werid when i was saying a few things about the hydrostatic valve etc

that seems prety farkin expencive

heres one quote i got:
Converter loose (not mounted very solidly)
Tank loose (i didnt tighten the bolts enough)
copper line changed to flexible line
fix up wiring in valve guard (excess cable to be removed)
duel fuel adaptor
requires fuel gauge (wasnt wired up, now is)

$850

I should have got in the lpg business like i was scheming a few years ago!!

[PGS 4WD]

There was never any money in the LPG game until the Government grant, just like the home grant prices go up and make it all just as dear as it was before or worse.

Joel

[460cixy]

Thanks mate.

So i have to flare the fittings ot what every is only for copper line?

I was going to use the flexi stuff for sure!


With the flexi line and adding the fittings to it etc is it like putting fittings in heater hose just push the end of the fitting inside the pipe oe does the fittings and hoses work different and can someone at home do themself?


I'm glad this forum is here becuase if i was to ask these questions at a LPG place they wouldn't even answer them they just would wither say it's to hard or they have to do it.


Thanks alot Rick

you will need a double flare tool for the copper line not a hardware shop single flare tool for plumbing. haveing one is handy because it can also glare brake tubeing ect. the flexy hose uses bolt on fitings one use only very simlar to hose fittings on hydraulic hoses on earth moveing gear.

[Guy From Nowhere]

Hey Piggy you get anywhere with that Sherwood mob? Just wondering what we are going with now? May as well put out how we are going to do it so it helps these guys.

Cheers
SANGA

[460cixy]

ile just get a price from down the road. im pissed i cant get them throu work