700 miles on LPG without needing to refuel

[LPGC]

I had a bit of a read of the Tooless thread again the other day, it's been a while since I last read it, got up to page 5 and will continue reading from there when I get time, a great read for a laugh!

What pressure can your home compressor run up to and what pressure do you usually fill your tank/s with?

I know most bottles are long and thin but there does seem to be a wide range of sizes, are there no shorter fatter bottles?

I agree the electrovalve/s and plumbing could be a problem but how about as a compromise instead of fitting bottle mounted electrovalves keep with the standard bottle manual taps and manually turn on just one or two bottles at a time, have a pressure gauge up front instead of one on each bottle? Or an inline electrovalve mounted close to the manual tap on each bottle and keep all the manual taps open? Either of those ways you wouldn't need to source electrovalves that would screw directly into thread designs of the bottles.

[CNG]

Yup. Still cheers me up.
The Tooless thread keeps giving. Remains one of the funniest things I've ever seen on t'internet. I recommend "How to Troll a Dating Site".

UK/Euro tends to be 200Bar - the Yanks run 250Bar.

[LPGC]

Your choices seem to be...
A. Try to source / buy a couple of big capacity purpose made CNG vehicle tanks, but you've been struggling for a long time to do that hence we got around to talking about option D.
B. Put up with small range on CNG
C. Forget about running on CNG
D. Go with some ad-hoc setup using none CNG road vehicle containers. This doesn't necessarily mean being reckless or making for something that is totally unsafe but probably does mean compromising in some ways while trying to remain safe and under-weight while having decent cng capacity / range.

Some older LPG tank multivalves didn't have an electronic shut-off solenoid but an inline solenoid was fitted close to the multivalve output by the installer. Not as safe as a solenoid built into the tank valve but a compromise that would prevent entire tank contents leaking as long as the short pipe between the valve and solenoid didn't break.

1. I don't remember the subject of container crash rating being brought up before, is this a newly discussed criteria? This completely limits you to ABC, unless you're prepared to compromise with D.

2a. Is this an excess flow shut-off valve? If it is you could have a minor leak and it wouldn't help, if there is a major leak (say a pipe snaps) there'd be a drop in pressure to the front end and the system would either switch automatically back to petrol or you'd switch back to petrol manually, in both cases this could cause an inline solenoid near the tank to close but if such valve isn't fitted and there is a manual valve you could close it manually if it is accessible. Excess flow valves only help prevent problems in a narrow range of circumstances - leaks much bigger than the rate of gas the engine can consume when running flat out (if it shuts off before that flow rate the engine can't run flat out on CNG anyway) but not big enough that the pipe has become totally broken/disconnected (if a pipe becomes totally broke/disconnected and you're running a system with an engine bay pressure sensor it will turn off gas at solenoids anyway, or if no solenoid is fitted you'd know there was a leak because the engine would die and you could turn it off manually at the bottle tap. It is unlikely a bottle would have an excess flow valve, so if you won't compromise on this you're limited to ABC.

2b. LPG vehicle tanks have over pressure relief valves and fire 'fuse' relief valves, don't some oxygen / nitrogen / CO2 cylinders also feature the same? If the answer is no and you won't compromise on it then again you're limited to ABC.

3. I mentioned a compromise setup in my last post after you implied you couldn't screw a CNG shut off solenoid to a none CNG tank, I mentioned the same thing above in this post with 'some older LPG tank multivalves'. If you'll never compromise by using a bottle that you can't directly attach a solenoid to (and if none CNG road vehicle tanks can't have a solenoid directly attached) then ABC.

What's been discussed are ways around and compromises but if you don't want to compromise on any aspect you're stuck with ABC and all of the talk about several small tanks weighing more than one large tank of equal capacity etc etc has been a bit pointless because you're not going to do it anyway, not even if we suggested a solution that was a lot lighter than a proper CNG road vehicle tank installation and with simpler plumbing.

I get the concern about the very high pressure in a CNG tank and feel a lot more comfortable with the much lower pressure of LPG. I dare drill holes etc even in a full LPG tank, there is no way I would dare do that with a CNG tank. I dare plug a hole I made in an LPG tank with a finger, wouldn't try that with a CNG tank because the pressure could take the finger off lol.

[hitman2]

Option c
Because it's a folly

[Gilbertd]

I agree with option C too. Ridiculously expensive and difficult to obtain tanks, very high pressures, scarcity of front end components, very short range, difficulty in setting it up such as having to use a TAP, inability to fill up anywhere other than at home (unless you are in Germany or Italy) all make CNG a non-starter.

As for your comments on the cylinder doesn't know or care, it doesn't. It's a pressure vessel and can be filled with anything. I've got a cylinder that says it contains R410 but has been filled with R32. It doesn't know or care that the label on the cylinder doesn't match what is in it. The difference in fittings is irrelevant, all tanks have different fittings so you can't easily connect the wrong tank such as Acetylene to something that requires CO2 for example. Fittings for a Propane cylinder are different to those on a Butane cylinder even. None of these are insurmountable, they just make it more complicated. If you can put up with the multiple downsides, experiment away, but don't expect many to agree with your choices.

[LPGC]

The negatives have been discussed in detail, the positive is that if you do most driving to and from home and have decent enough range it's extremely cheap to run on CNG.

The right vehicle with the right tanks fitted could be worth it, especially for someone who already has a CNG compressor plumbed in at home. But if they can't buy purpose made tanks and are not willing to compromise on tank spec decent range might not be achievable.

Could set up a hybrid system, enough range on CNG for say around 100 miles with an LPG setup to fall back on for longer trips.

[CNG]

Yes Simon gets it.

With caveats, that point was made at the start.

[CNG]

Thus it works for me, but...

That's because of the way I use it. And 'sunk' cost.

[Gilbertd]

Range is rarely the issue. Lowest range is my 'classic'. Has 80 miles at best - I do the same 45-50 mile round trip 2-3 times a week + supermarket/ pub-run. Would not work for many, fits for me. Trips more than 450-500 miles 'round' are rare. I suffer petrol or fill @ DiRFT / Crewe etc when it is. In 22000 ish household miles, if our petrol bill was £200 for the last year, I'd be surprised.without paying 'daft'.

Sounds like the ideal candidate for an EV to me.... Refuel at home, only do short journeys, etc. How much do you spend on gas though? While it may work out considerably cheaper than petrol, you are still paying for it. Current price is around 7p per kWh so you may not be spending money on petrol, you are spending it on gas, only it's hidden in your domestic bills. Just the same as the EV owner who charges at home and seems to think they are running their car for free even though they are paying for it in their domestic bills. At one of the labs where I used to work, a staff member bought a Nissan Leaf which had just enough range to get to and from the lab in summer, but in winter with wipers and lights on, it couldn't do it. So she would run an extension lead out to her car to top it up during the day. Then someone put in a claim for his petrol to get to work and back using the argument that they were paying for her to get to work and back so why shouldn't they pay for everyone else?

Last but not least... I can see CNG worse than useless, actually harmful. Living hell for the bloke with a Rooney hellbent to run it all over the continent.

Why harmful? Not just the Continent but the UK too. I use my car, it's a tool to get me places that I either need to go to or want to go to without a second thought. I've gone through 170 litres of LPG in the last week and are quite likely to do the same this coming week.

[CNG]

I suppose an EV would work.

[Gilbertd]

One thing we totally agree on then, the ludicrous cost that people pay for finance/lease/hire charges on a new car (EV or conventional), nothing below about £200 a month for something you will never own and are restricted to tiny mileages too. I saw one recently for an Audi RS3, a very nice car if you like that sort of thing, list price if you want to buy one, £115k, or if you want it on deal, something like £23k up front, then £1.4k per month for the next 5 years but restricted to no more than 5,000 miies a year. Do people actually spend this kind on money when they could buy a 5 year old one outright for £35k?

£4.1k on the compressor? No wonder you are sticking with CNG after that kind of outlay..... As best I can find with a quick Google is that 10kW of methane is around 1 cubic metre,so that will be costing you around 70p. So by how much do you need to compress it to get that 1 cubic metre up to 200psi? So what volume is it down to? As I say, it may be cheap but you aren't running on free fuel if you are taking the gas from your metered mains supply.

My car fills a number of functions and it does them all. I can drive, in relative luxury and comfort, for many miles at a decent cruising speed and get out at the other end without feeling that rigor mortis is setting in. Now there are probably many other cars, running on petrol, diesel, LPG or even CNG, that I could do that in (although not all if leg and back ache after a couple of hours in some of the company vehicles I've had over the years are anything to go by). But it can also tow a fully loaded 3.5 tonne trailer for many miles, also at a decent cruising speed, in relative luxury and comfort. Not only that but it has plenty of load space. It can carry a full domestic/small commercial air conditioning system, along with all the tools and equipment needed to install it and, if it is a larger install, what won't go in the car can go in my small box trailer (and I've had to add a small flagpole to that so I know it is still there, the car doesn't notice it). It does everything I ask of it, including towing a 4 tonne trailer up the side of a mountain in the Alps and negotiating roads covered in 42cm of snow last December.

So as a replacement for my Rooney as you insist on calling it, I could have a luxury passenger car for my long distance journeys, a small truck (and lose the comfort and luxury) for towing and a van for my AC installations and, if I chose to go to somewhere with lots of snow, I'd need something with that capability as well. That would be at least 3 lots of road tax, maintenance, servicing, etc, not to mention ending up with a house looking like a car park. So while there are those that look down on them, including many Land Rover owners who consider it isn't a 'proper' Land Rover, I can't think of anything else that will do what I need in the one vehicle. Incidentally, as for the ignorant Series and Defender owners, a little snippet that they won't want to hear. Back in 2001, when my model of Rooney was current, we had Discovery's at work for accessing hilltop radio sites and one guy managed to tip one over. As a result, all of us that drove one were sent to Land Rover to do the off road course. I arrived there after a week of rain and looking at a deeply rutted, mud, hill, concluded that you would need a Defender on big tyres to get up that. 30 minutes later I was driving up it in a Discovery on standard road tyres. After being astounded at just what these were capable of if you knew how to drive one, I asked the instructor which LR product was the best off road fully expecting to be told the Defender. His reply was the Range Rover on air suspension was by far and away better than anything else they had ever built as it had been designed from the ground up and not just a development of a previous model like the Defender was. He reckoned that in the right hands even a Freeloader could go places a Defender couldn't.

[CNG]

£4100 dear? Why?

[LPGC]

I reckon we should end this thread here

Well I said what I was going to say about 700 miles on LPG without needing to refuel due to having my easily added / easily removed quick fit extra tank fitted and refuelling with LPG at home from red bottles using one of the pumps I sell

[CNG]

We near forgot.

Did anyone know Simon sells pumps to added / easily remove /quick fit extra tank fitted and refuelling with LPG at home / from red bottles using one of his pumps.

Someone should say. Why did no one mention it?

[LPGC]

[LPGC]

The extra tank holds around 80L of LPG, good for around 350 miles range at only 20mpg.

IIrc the extra tank I fitted is something like an 360/80 (360x890mm). The tank itself weighs around 35kg, then there's the weight of the tank valve, frame, piping etc but they don't add up to much, say 3kg, so the tare/empty weight will be around 38kg. The 80L of LPG weighs 40.8kg, so to add the extra 350 miles range adds a total of around 78.8kg. So we could do 350/78.8 = 4.44 miles per kg of combined tank and fuel weight. When full the extra tank and fuel would add 78.8kg but when empty the extra tank and no fuel adds 38kg.

An extra tank that could carry 100 litres could be a 400/100 (400x880mm) which bare weighs 38kg, add the tank, frame, piping, etc and it still only adds 3kg, so the tare/empty weight would be 41kg. The 100 litres of LPG would add 51kg for gross/full combined weight of 89kg giving 439.5 miles extra range. Could do 439.5/89 = 4.94 miles per kg of gross/full weight... When full it would weigh 89kg, when empty would weigh 41kg.

The two tanks are close to the same length (the bigger capacity is 10mm shorter) but the bigger capacity is wider, 400mm compared to 360mm.

If we're still willing to stay on subject (since it's gone from 700 miles on LPG with my extra tank and refuelling at home from red bottles using a pump, to CNG range etc ) How does CNG compare on miles per weight and full/empty weights with a proper/ideal CNG tank versus other types of cylinders?

[Pinger]

If nothing else comes of this thread, it should act as a reminder of the sheer usefulness of fuels that are easily liquified.

[CNG]

We have LNG. Where a LNG cylinder = any CNG cylinder + a Thermos flask. Metane like butane/ propane goes liquid. If cold enough. I dare not ask how much a LNG cylinder costs? I do know you want Scania tractor-cabs to move the things.

[LPGC]

In that context... and ahem, to benefit 'the 2 sec think brigade', I'll say twice more...

We seem to be hung up on 'The cylinder does not care', I think there's probably been a misunderstanding... We / Gilbert has been saying that a tank has to be chemically suitable for whatever we put in it, plus it also has to be capable of withstanding the pressure of whatever we put in it. Is it not true that a CO2 or oxygen container would be chemically suitable for cng? Is it not true that if said container is rated for 200psi we could stick 200psi of cng in it? I think maybe you have been concentrating on the weight versus capacity aspect? Of course this is still aside from the subject of over-pressure relief valves and thermal fuses.

[hitman2]

200 psi, don't cut the mustard, cng requires 200barg.

Its a folly anyway and we ALL know that