LPG high pressure or low pressure? Confused!

[gravygraham]

Hello Arthor, please take note of the replies from Aquapower and the like. I too used to be Corgi registered for LPG and your questions tell me you really shouldn't be tinkering about with gas appliances or fittings and pipe work. You've done the right thing to ask for help, but on behalf of the forum and anyone who may berth near you, please get a qualified and competent professional to undertake the work for you.

 

[VicS]

Hello all,



Any guidance would be most welcome.

many thanks in advance

arthor

Please, please, please do not attempt this work yourself.

Your posts, the questions you ask and the other points you raise clearly show that you do not have the knowledge or understanding, even if you have the practical skills, to carry out work on your gas system yourself.

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[rbcoomer]

I too would urge that you get someone to install. What price do you put on your life and those around you? I've seen some awful domestic gas and electrical installations over the years and it's all to easy to think it's simply a few pipes, but there's more to go wrong than you think. I have a car that runs on LPG and that's probably the least regulated gas market, but even there most garages not qualified won't touch. 5/6bar of pressure is dangerous on it's own before you factor in the volatility of the compressed gas! Unlike petrol that tends to leak and evaporate relatively slowly, gas under pressure escapes very quickly. As mentioned above there's also exhaust gases, correct combustion and proper ventilation to consider. Carbon monoxide is lethal as a couple of headline cases last year illustrated - please learn from the mistakes of others and get it certified safe!

 

[arthor]

I was in no way trying to belittle Corgi fitters. I often pay them to do work in my house. I would imagine that they themselves pay a great deal for any licensing they require. There are many areas that the government likes to license and they do see it as a money making exercise. Some of these are more license worthy than others.
I appreciate what you have all said and will take it on board.
I think taking 15mm from the regulator to the water heater is a good idea and then step down to 8mm for the hob. They are all in a straight line with just the hob forward of a bulkhead and not in an open area. I understand that you can see water if it leaks but a test valve enables the same check to be carried out for gaswork. Surely the bottom line is that if the surveyor is happy then it must be ok if he checks the pipework and system for leaks and security.
My main query was about the flexi and as that was to do with high and low pressure systems, it was that which I wanted clearing up.

 

[gravygraham]

What's so special about your house that you use qualified and competent gas fitters?

Would you be man enough to tell the forum the name and make of your boat please? We can then keep ourselves a safe distance from the threat of your botched gas work.

 

[VicS]

Hello all,

I am getting giddy and trying to get the boat through it's BSS inspection. I am redoing the gas system to make it simpler to get at.
My confusion comes from looking at the BSS PDF section 7. It refers to high and low pressure systems. I have no idea which is which or if mine is one or the other. Does it depend upon the gas used? The number of appliances?

Any guidance would be most welcome.

many thanks in advance

arthor

My main query was about the flexi and as that was to do with high and low pressure systems, it was that which I wanted clearing up.

High pressure refers to the part of the system from the cylinder to the regulator. This part is at the same pressure as the gas in the bottle. FWIW the pressure in a propane cylinder is much higher than that in a butane cylinder and the exact pressures vary with temperature but nevertheless the part of installation up to the regulator is the high pressure section.

The regulator reduces the pressure to a few tens of millibars. The exact pressure depending upon wheter you are intending to use propane aor butane or are intending to install a dual fuel system that can use either.

The parts of the system after the regulator are the low pressure parts........ because they operate at a much lower pressure than the pressure in the gas cylinder.

The size of the pipework required will depend upon the gas flow required by the various appliances you are fitting. The manufacturers literature, or installation instructions, should give guidance on pipe diameters.

If you are installing a gas system or even modifying an existing system you should be aware of and understand the two test procedures that are required to ensure that the system is sound and free from leaks. You will also need the equipment that these tests require and understand how to use it.



If you do not know the details of these tests, do not understand them, do not have the necessary equipment or still do not understand the difference between high pressure and low pressure then do not attempt to do this work yourself ... you are not competent to do so.

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