lpg feed pipe size on 500 bhp engine.

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LPGC
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Re: lpg feed pipe size on 500 bhp engine.

#221 Post by LPGC » Sat Dec 22, 2018 8:55 pm

Yes, and Calor bottles etc are filled to 90% and they're expected to be filled in the cold then sit in someone's living room where' it's nice and toasty.. perhaps even actually inside one of those SuperSer heaters directly behind the burners.
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Re: lpg feed pipe size on 500 bhp engine.

#222 Post by robertXX » Sat Dec 22, 2018 8:59 pm

ok brilliant , simon thank you , any idea of the difference in quality or outlet flow between the two types of valve mentioned ? they are both 49 odd quid ,and called 8mm outlet .

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Re: lpg feed pipe size on 500 bhp engine.

#223 Post by LPGC » Sat Dec 22, 2018 9:15 pm

I'd definitely go for the Tomasetto valve, the Atiker valves are far less common and seem to be most often fitted as part of unusual brand Eastern European / Indian / etc one make full system installs such as Stargas etc, I've known plenty of these valves fail, some even to leak on the seal between the valve and the tank, I don't rate them. The Tomasetto will be reliable, you can easily buy valve splash/dust covers (external installs) / gas tight boxes (internal installs), etc that work equally well with 8mm outlet valves as 6mm outlet Tonasetto valves, only the diameter of the outlet plumbing and pickup tube is different between Tomasetto 6mm and 8mm outlet valves.

I believe Emer don't make valves any longer. An Emer / Atiker valve won't work with a Tomasetto cover or box. But there are still Emer valves available and they were/are handy because Emer make a flexible gas tight housing, and also make the 'upside down' valves I mentioned in an earlier post. The combination of upside down valve and flexible gas tight housing was ideal for some vehicles such as X5's and L322 Rangerovers but all the 270mm height valves have already been used, so on such vehicles I now fit Emer 250mm upside down valves and modify the valve to suit the 270mm tall tank.
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Re: lpg feed pipe size on 500 bhp engine.

#224 Post by LPGC » Sat Dec 22, 2018 9:18 pm

Did you notice my edit on post number 219... I touch on an often overlooked aspect of tank filling in cold conditions.

I might add to that post that there is also the opening pressure of the one way valves to consider (fill point and tank valve's). If the difference in fill pump pressure and tank pressure isn't enough to overcome a one way valve's opening pressure it will mean there isn't enough pressure to pump any gas into the tank. If in this weather a fill pump pushes gas to the tank at 8bar 120psi and a one way valve takes 15psi to open then the pump won't have enough pressure to push any gas into a tank that has 105psi. In this weather (sub 10C) an LPG tank will only have around 75psi of LPG pressure but if we add to that the one way valve's opening pressure of 15psi we get 90psi before any gas will flow into the tank. 90Psi is 6 bar, a tank containing air that has it's volume reduced (say by incoming liquid such as LPG) to 1/6th original volume (filled to say 83% with LPG) will have air pressure of at least 6 bar hence an LPG forecourt pump pushing only 8 bar won't be able to fill said tank above 83% full anyway.

I've noticed over the last few years that forecourt pump pressure has been coming down (on pumps that have pressure gauges such as some Morrisons pumps), I expect this is well intentioned but poorly thought out - it seems to err on the side of caution to a ridiculous extent and does slow the speed of filling for most users especially as tank fill level gets above around 70%.

When fill speed slows as a tank becomes progressively full (and while the tank's fill valve is open because the float isn't high enough to engage the fill valve shut-off) it is due to air pressure in the tank, as LPG pressure in the tank will remain the same almost regardless of tank level unless the tank is approaching 100% full. I believe low pump pressure due to ill advice from ill-informed PC people/organisations/trade bodies is the reason we are suffering a bit longer fill up times these days compared to a few years ago, and sometimes not often managing to fill tanks to even 80% in cold weather conditions.
Last edited by LPGC on Sat Dec 22, 2018 10:15 pm, edited 5 times in total.
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Re: lpg feed pipe size on 500 bhp engine.

#225 Post by robertXX » Sat Dec 22, 2018 9:30 pm

I did just read it thank you. My local pump has a gauge on it that shows about 150 psi when it starts pumping then as it nears cut off it goes up to about 185 ish. Maybe even 195.

Re this. outlet plumbing and pickup tube is different between Tomasetto 6mm and 8mm outlet valves.

Isn't the solenoid a different size internally. I seem to remember reading a normal is 3mm I'd and the high flow one is 5 mm. ?

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Re: lpg feed pipe size on 500 bhp engine.

#226 Post by LPGC » Sat Dec 22, 2018 9:57 pm

It's a wider diameter pickup tube on Tom 8mm valves. The diameter of gas routes under the outlet solenoid''s plunger and of course the outlet are also wider.

8mm Outlet valves haven't always been available on MV tanks but have always been available on 4 hole tanks, before 8mm outlet MV valves were available and before nylon hose was available it was common practice to fit 6mm to 8mm outlet adaptors on 6mm outlet tanks and make the main run of (copper) pipe all 8mm. Wider outlet MV's make some difference but the main difference is diameter of main pipe run - You could get 400bhp from a 6mm outlet tank with 8mm adaptor and gas pipe and 450hp with 8mm outlet and 8mm pipe runs, but with all 6mm would be struggling at 300bhp in summer (with warm gas temps so higher tank pressure... in a situation where it's only tank pressure that pushes gas to the engine bay).
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Re: lpg feed pipe size on 500 bhp engine.

#227 Post by robertXX » Sun Dec 23, 2018 7:37 am

ok dokey i shall get the tomasetto extra 250mm valve , i would getf he 270 valve for more tank cap , but they are out of stock !

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Re: lpg feed pipe size on 500 bhp engine.

#228 Post by robertXX » Sat Dec 29, 2018 9:52 pm

Ok dokey.

Well on the plus side Lpg shop sent the right multivalve. And it got here today. On the neg side they sent the wrong fitting we orders with it. I wanted a 8 mm to 8 mm connector. And got a 8 mm to poly pipe. Pox.

Now I have to hope they get me one by mid week so I can still go to Bicester scramble.

And work out how to get 2 litres of propane out of the tank , without blowing myself up.

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Re: lpg feed pipe size on 500 bhp engine.

#229 Post by Brian_H » Sat Dec 29, 2018 10:55 pm

Outside somewhere when its windy and not too many people about with no drains nearby (as the gas will drop to the lowest point), then open the valve (remove solenoid post first with the shut off closed, you can put the post without the plunger inards back in place and use the output hose to direct it somewhere sensible). Or find some way to connect it to something you can burn it in (lawnmower engine, heater or similar, its only 2 litres worth) if you let it leak slowly out of the valve it will take a fair while, but not too long.

Unfortunately lpgshop seem to do that occasionally.

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Re: lpg feed pipe size on 500 bhp engine.

#230 Post by robertXX » Tue Jan 01, 2019 3:03 pm

Thank you Brian , that worked well , it did take a while but got it done , now i have the inside of the tank to look at ...


Image


it all looks pretty clean , so thats nice , and i am wondering about annoying the h and s people a lot ...



i looked at the float mechanism on the new valve , and it appears to bo a system where the float rises ,and gets to a point where it uncovers a push rod that pops out and stops flow ? how it then lets the float drop down as you use the gas i do not know .


NOW , as my valve is described as for 240 to 250 mm high tank , i can assume that in a 250mm tank i wont get my full 80 % but if i had a 240 mm tank i would , so my float is maybe teschnically 10mm too low at cut off point ?


add to that that i want as much gas as possible in my tank , and simons comments on the 10% is enough exp area,, is it dare i say it feasble to BEND the float arm ...if so , but how much ?



here s how she sits with the simulated pin in place holding the arm up ,and oriented correctly as it would be in the tank ..


5mm tap being the pin..

Image



Image


Now , everyone is either hiding under their duvets/workbench 's ,crying and repeating "make it stop" at this point , or have some experience in this .:)




regards robert .

HAPPY NEW YEAR !

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Re: lpg feed pipe size on 500 bhp engine.

#231 Post by Brian_H » Tue Jan 01, 2019 4:46 pm

Trial and a lot of error - Make the valve accessible where your going to install it makes that a lot easier.
I've had a valve on a 160l tank that the best I've managed to fill to is 110 litres initially, and every attempt to correct it to somewhere more desirable has either ended up with less going in, it not shutting off as it hits the side of the tank, or very little change. Its probably easier on a torroidal tank as you have less to adjust with.

You really need to have it somewhere you can use the contents if your trying that method as obviously you want/need to use the gas inbetween each attempt.

Simon might advise further if your lucky!

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Re: lpg feed pipe size on 500 bhp engine.

#232 Post by LPGC » Tue Jan 01, 2019 8:30 pm

Lift the float to the point you can see the pin is going to come off the cam then bend the float arm up the 10mm. Nice if you can bend the arm in a position which still allows it's full range of travel - if you bend it close to the float the float may always be 10mm from the bottom of the tank when the tank is empty so usually the best place to bend is as close to the valve body as possible... but sometimes if there's already a bend in the float arm (sometimes there is already a bend around 5cm from the valve body) the same thing can happen unless you bend the arm closer to the existing bend.

Sometimes you'll get less gas in on early fills after first modding the tank due to points I mentioned in post #224.. You let air into the tank when you had the valve off. Since mixer systems are more likely to allow the engine to run when there's only vapour left in the tank they are more likely to deplete air in tanks when run to completely empty.

Some people.. I won't mention who lol.. on some installs (maybe their own).. disable the fill limiter altogether by removing the cam (cross drill with a 3mm bit, snap off with pliers, clean up any remaining sharp protrusions with a bigger 8mm drill end on to the shaft), then fit something for the pin to ride on instead of the cam (a self tapper through the plastic, pilot hole the plastic with a 3mm bit first). If the pin is too far in it prevents gas entering the tank, if it's too far out it prevents gas from entering the tank, so the self tapper has to be in the correct position, you cleaned up the remnants of the cam to prevent it catching on the self tapper which would otherwise prevent the float moving.
Last edited by LPGC on Tue Jan 01, 2019 8:39 pm, edited 1 time in total.
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Re: lpg feed pipe size on 500 bhp engine.

#233 Post by robertXX » Tue Jan 01, 2019 8:32 pm

big problem brian is , it only runs on gas , so every time the tank is empty i have to either tow it to the stn 6 miles away or decant some from my expensive orange bottle .

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Re: lpg feed pipe size on 500 bhp engine.

#234 Post by robertXX » Tue Jan 01, 2019 8:34 pm

oh dp.
Last edited by robertXX on Tue Jan 01, 2019 8:38 pm, edited 1 time in total.

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Re: lpg feed pipe size on 500 bhp engine.

#235 Post by robertXX » Tue Jan 01, 2019 8:38 pm

robertXX wrote:
Tue Jan 01, 2019 8:34 pm
oh and there he is !!!



LPGC wrote:
Tue Jan 01, 2019 8:30 pm
Lift the float to the point you can see the pin is going to come off the cam then bend the float arm up the 10mm. Nice if you can bend the arm in a position which still allows it's full range of travel - if you bend it close to the float the float may always be 10mm from the bottom of the tank when the tank is empty so usually the best place to bend is as close to the valve body as possible... but sometimes if there's already a bend in the float arm (sometimes there is already a bend around 5cm from the valve body) the same thing can happen unless you bend the arm closer to the existing bend.

Sometimes you'll get less gas in on early fills after first modding the tank due to points I mentioned in post #224.. You let air into the tank when you had the valve off. Since mixer systems are more likely to allow the engine to run when there's only vapour left in the tank they are more likely to deplete air in tanks when run to completely empty.



brilliant thank you simon , i will do that tomorrow .10mm ,and no more ?

oh , an by PIN GOING TO COME OFF THE CAM , do you mean the part up against my tap i poked in the hole is the pin , and the cam is the bit on the float arm that uncovers the hole i put the tap in , so basically as i have it in the photo?

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Re: lpg feed pipe size on 500 bhp engine.

#236 Post by LPGC » Tue Jan 01, 2019 8:43 pm

I'll have been editing my post while you were posting Rob..
More than 10mm if you like but bear in mind that at some point the float will touch the top of the tank and the valve still won't be closed. On say a 250mm height tank would expect the float to shut off gas at 200mm, bend that float arm up 25mm and the tank should fill to 90% but bend it up 50mm and the tank will fill to 100%. OK bad example but you get the jist, with the 50mm bend the 100% fill would be limited by the capacity of the tank rather than by the valve closing.
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Re: lpg feed pipe size on 500 bhp engine.

#237 Post by robertXX » Tue Jan 01, 2019 8:50 pm

do you think 25mm would be leaving enough room for exp ?

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Re: lpg feed pipe size on 500 bhp engine.

#238 Post by LPGC » Tue Jan 01, 2019 8:55 pm

robertXX wrote:
Tue Jan 01, 2019 8:38 pm
oh , an by PIN GOING TO COME OFF THE CAM , do you mean the part up against my tap i poked in the hole is the pin , and the cam is the bit on the float arm that uncovers the hole i put the tap in , so basically as i have it in the photo?
Not the best of explanations sorry..
The float arm turns the crescent shape metal I refer to as the cam. The pin is the part that is pushed out of the little hole when gas pressure is applied to the valve inlet port, if pushed out far enough it closes a valve on the inlet port and prevents filling but when the float is low enough it hits against the cam so the inlet valve is open.

Difficult to just put a self tapper in the pin hole because if the pin is too far in the inlet valve is also closed so that would prevent you filling by default. Also if you put a self tapper in the pin hole it would foul against the cam so the float would be stuck and the gauge wouldn't work. By removing the cam and drilling both plastic protrusions that surround the cam inline with the pin hole you can put a (single) self tapper through the drilled holes for the pin to rest against when you're filling.
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Re: lpg feed pipe size on 500 bhp engine.

#239 Post by LPGC » Tue Jan 01, 2019 8:56 pm

Yes you put your tap in the pin hole.. That would probably prevent you filling at all though.
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Re: lpg feed pipe size on 500 bhp engine.

#240 Post by LPGC » Tue Jan 01, 2019 9:08 pm

robertXX wrote:
Tue Jan 01, 2019 8:50 pm
do you think 25mm would be leaving enough room for exp ?
I just scanned through recent posts but haven't found the height of your tank.. You could do your own calculations based on what I said in post #236 though. E.g. If your tank is only 180 height we'd expect a headroom of 36mm if the tank is to fill to 80% so if you bend the float arm up by 25mm that would only leave headroom of 11mm so that tank would fill to 94% if the float's radius wasn't wider than 11mm otherwise it would fill to 100%.
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