Fitted the new reducer today and decided I can no longer live with the bodge job that is the 6mm copper main feed line from tank solenoid valve to reducer solenoid valve.
The cable ties to the chassis in parts, the routing in exposed areas and the ever dwindling length of the tail in the engine compartment are just some of the reasons.
As I'm going to be underneath fitting the new exhaust it seems like a fine time to get on with it.

Anyway- my questions:
After leafing through Tinley's catalogue, I've decided to go with 6mm Faro polypipe (unless 8mm would be better for a 4.6 V8 and long pipe run). Will a single run of pipe with an M10 connector direct to the outlet solenoid valve (tank end) to an M10 connector to the inlet solenoid valve (reducer end) be an acceptable standard? I'm thinking that it sounds too easy and there's probably a rule that says I have to go to solid copper pipe first at both ends or something even stranger that I haven't considered.
So- these fittings

One at each end- can it be that simple?
Pipe to be secured by P clips- that's easy, but do I secure to the chassis rails (the vertical faces!) or to the floor pan?
Chassis rails sounds best to me, although given the thickness of the metal I'll have to budget for a handful of drill bits, but where should it be fixed?
Finally (and probably my daftest question), is there a requirement to electrically bond the 2 ends of the pipe together (ie run a length of cable between them). There is on domestic plumbing where polypipe is used in conjunction with copper, for earth continuity.

Thoughts, input and experiences most welcome!

I've just uploaded the LPGA (now UKLPG) Code of Practice to Google Drive for you https://drive.google.com/open?id=1q91-U9r6C5otXeuujL8WUldzoJ99tzfX

No requirement for electrical conductivity, and the pipe run needs to be located where it can be examined for damage, protected from damage and securely fixed. Although 6mm would probably suffice, I'd go with 8mm to be on the safe side. Using Polypipe is easy, that's why people use it.

Thanks Gilbertd- I'll read that over my breakfast this morning
Currently wondering what the minimum bend radius is on polypipe...

Minimum bend radius is pretty tight, obviously better for the 6mm equivalent than for the 8mm equivalent. Based on memory I'd say a bend of 90degrees in about 6 inches for the 8mm pipe is OK. Not as tight as is possible with copper but is a lot more forgiving than copper, a kink will unkink.

4 Hole tanks usually have flange fitting outlet valves that would need an adaptor to use Faro (flange fitting Faro adaptor or flange fitting to olive fitting adaptor to normal faro end).

Can buy all sorts of fittings for 8mm Faro pipe, such as ends to fit in 8mm or 6mm olive joins, M10/M12 thread, straight, 30deg, 90degree, etc.

If I were changing 6mm copper pipe on a P38 to Faro I'd go with 8mm equivalent, especially if the reducer solenoid had 8mm inlet. I very seldom use 6mm equivalent on anything at all... Just converted a Ford 1.6 which got 8mm.

If there's any downside to polypipe at all it's that it won't stand as much heat as copper. Of course we shouldn't be fitting any pipe close to anything hot enough to be a concern anyway but question marks can arise when you have a vehicle with, say, a big back box under the width of a spare wheel well, a heat shield will then usually sit between the well and the back box, best type of tank to fit might be 30deg but even for pipe running above the shield there might be concern if using polypipe. On balance Polypipe is better in most respects, it won't break if fitted between components where there is bit of movement either.

Some of the Cop11 rules for pipe runs seem to make less sense for polypipe.

Usually when we talk about Polypipe we refer to Faro pipe but other brands are also common. Although the main brass part of end fittings will work across brands the end caps and olives are brand specific due to differences in internal diameter vs external diameter.

Thanks Lpgc- I'll have a look at the fitting on the outlet valve tomorrow to see what sort I have.
As I'm fitting a new exhaust system at the same time as the LPG line, I'll be able to avoid potential hotspots with some creative routing (hopefully)

If it's a single hole tank the outlet is likely to be M10 unless it has a rather old design multivalve in which case it could have flange fittings.

As said on the other thread make sure your solenoid inlet is M10, the one you pictured could be M10 or M12.

Easy to avoid running pipe close to hot parts on a P38.

Solenoid inlet is definitely M10- that's one bit I am sure of :)

Fittings checked, appropriate bits ordered!

Dumbass questions time. I wish there was a good tech book I could read on all aspects of LPG, then I wouldn't have to ask this basic stuff, but anyway.

I assume the thumbwheel pictured is a shut off valve pre outlet solenoid valve, and with this closed I could, if I wanted, remove solenoid valve without getting a faceful of LPG?

Why is there no manual shut off valve on the inlet side? Would I have to rely on the non-return valve that must be in there somewhere if I wanted to disconnect?

Now the really stupid question. If I needed to empty the tank to, say, remove the multivalve, how?!
My gung ho approach might be to take tank into middle of cow field (minus cows!). Attach very long cable to solenoid. Put 12v through solenoid. Vent contents to air, hoping that breeze didn't drop.
To me that's fraught with illegality, risk of losing self and village in a fireball, nothing but bad things.
So how do the professionals do it?
Reason I ask is because I only ever seem to get 35 litres in before pump cuts off, and only 35 litres out before system shouts enough and switches back to petrol, so likely something is wrong with multivalve. For £40 ish for a new one that would seem like the way to go.

Yes, thumbwheel is the manual vlve so you can remove the solenoid plunger if you feel the need. Yes, there's a non return valve in the inlet and another in the filler so all that will come out is the contents of the bit of pipe between the two.

To empty the tank do just as you said. Park the car somewhere windy and with no drains or hollows as Propane is heavier than air and will pool wherever it can (so on top of a hill is ideal). If you don't want the car to stink of Ethyl Mercaptan, the odorant that is put in Propane so you can smell a leak, attach a length of pipe to the outlet and run that to the outside of the car. Using a battery, switch and 20 feet of cable, open the solenoid and keep upwind of it (or you and your clothes will also stink for weeks). Using a switch is far less likely to cause a spark than dobbing a wire onto the battery. It'll take a while and look pretty spectacular as 1 litre of liquid will become 270 litres of vapour..... Don't worry about the cows though, it's nothing to the amount of Methane they produce.

Gilbertd wrote:

Don't worry about the cows though, it's nothing to the amount of Methane they produce.

---

More worried about them running around burning really. Farmer would be most upset if I attempted an impromptu barbecue with his prime milkers.
The field is at the top of a hill, so no worries there. Only problem is the village is in a natural bowl at the foot of the hill, so need to make sure the wind's not blowing in that direction...

The correct way to dispose of LPG is to hook it up to a barbeque and invite 30-40 of your closest friends around for a hog roast :)

Bring the tank to Marty's workshop, we'll build....ah shit. The disco is gone. We'll find something else and build a BBQ!

We'll bring the food if Miles can lend his culinary expertise ;)

If I get it wrong there'll be a herd of burning cattle stampeding up the M4 anyway. The exercise should tenderise the meat nicely as well.

Orangebean wrote:

Gilbertd wrote:

Don't worry about the cows though, it's nothing to the amount of Methane they produce.

---

More worried about them running around burning really. Farmer would be most upset if I attempted an impromptu barbecue with his prime milkers.
The field is at the top of a hill, so no worries there. Only problem is the village is in a natural bowl at the foot of the hill, so need to make sure the wind's not blowing in that direction...

You've not got the worst of problems there to deal with as you can at least run it to the point where it changes back due to lack of pressure - this would remove most of the contents of the tank (and 35l of gas would add approx 18kg to the weight of the tank anyway) just by using it up. Thats only a concern if you need to remove it though, looks like you could avoid having to do that.

I've found the few tanks I've had to deal with taking them somewhere out in the open and slightly undoing the solenoid post is enough to allow them to vent - you just leave it to do so until the pressure has gone. If the tanks staying inside the vehicle same process just put the gas tight box back on it and allow the vent tubes to vent it outside.

Don't undo it too far though, else it will shoot out! just undo it until you start getting gas hissing.

I'll report back on the success (or otherwise) when I attempt it!
Need to get the new line installed and tested first so it won't be for a while.

Yes, pros sometimes use the same approach you were thinking along the lines of! But since you can use the gas (just that you can only get 35L in the tank) why would you need to vent it's contents? Run the tank to empty, then look into changing the valve.

Does the stamp in the brass (for tank height) read 220 or 270? Should be 270, I can't see it properly in the pic but looks like could be 220, if it is 220 that would affect how much gas you can get in.

I'll have a look at the stamp tomorrow. Cold and damp outside and I'm toasty indoors.
EDIT- just looked at the full size pic. Looks like 220 to me, but still fuzzy

That's why it won't fill fully then, it's set for a 220mm tank not a 270mm one.

So, the internal float is linked directly to shut off fluid input? Max capacity (the 80% thing) is determined by float height, not tank pressure?
.
Float also drives level indicator I assume?