Gas pipe run help

[Feeby100]

Hello I am about to run the pipe for gas to serve the hob oven and boiler alde 

now what size pipe please 

and can I box this over in the gunwales ? 
I know I have to clip it every foot I think ? 

[Alan de Enfield]

10 minutes ago, Feeby100 said:

now what size pipe please 

 

You need to work out how much gas is used by every appliance on full power, then convert that to the size of piping needed so as to minimise pressure drop.

There are charts available to assist.

 

 

10 minutes ago, Feeby100 said:

and can I box this over in the gunwales ? 

 

The gas pipe MUST be capable of being viewed over its entire length, so if you box it in you will need to make the 'boxing in' removable for the BSS inspection.

 

 

If running under the Gunwales check to make sure there are no single core cables there, as there is a minimum spacing requirement between gas piping and single core cables (Mulitcore cables that are insulated AND sheathed can be adjacent to (even clipped to) the gas piping).

 

Are you planning to have the installation 'signed off' by a Boat certified LPG Gas Fitter ?

The fact you are asking the questions may suggest that you would not necessarily comply with the definition of 'competent to instal' as is required.

Edited June 10, 2022 by Alan de Enfield

[Jen-in-Wellies]

Length of the run also makes a difference. Longer pipe runs need bigger bore pipe to get the same flow rate, so how far is the appliance from the bottle?

[Tracy D'arth]

4 minutes ago, Alan de Enfield said:

 

You need to work out how much gas is used by every applinace on full power, then convert that to the size of piping needed.

 

 

 

The gas pipe MUST be capable of being viewed over its entire length, so if you box it in you will need to make the 'boxing in' removable for the BSS inspection.

 

 

If running under the Gunwales check to make sure there are no single core cables there, as there is a minimum spacing requirement between gas piping and single core cables (Mulitcore cables that are insulated AND sheathed can be adjacent to (even clipped to) the gas piping).

Single insulated cables must be spaced away from gas pipes but insulated and sheathed cable need not be.  

You need to know the maximum volume of gas required for all appliances connected and the length of the pipe run to determine bore size.  

[BEngo]

To answer the first question  you need to look at the appliances and work out their maximum gas consumption  rate, then find the length of the pipe and from that work out the pipe size.  Most people find that 1/2 in pipe is adequate.  Older  installations commonly used 3/8 in.   You should get the right sort of copper pipe.  IIRC you want Table X.  

Your gas regulator(s)  also needs to be sized to pass the maximum gas demand.

 

The gas pipe and all its fittings must be readily accessible- ie you can see it all  including joints and fittings,  without needing tools.  Clip on boxing in is OK, screwed on isn't. 

 

Clipped every 300 mm or less is fine.

 

You should be aware of the requirements of the Recreational Craft Regulations and of the Gas Safety Installation and Use Regulations, both of which may be relevant, especially for a liveaboard.

 

N

[Alan de Enfield]

Just now, Tracy D'arth said:

Single insulated cables must be spaced away from gas pipes but insulated and sheathed cable need not be.  

 

Exactly what I said.

 

How many multicore cables do you know that do not have a sheath, and how many single core cables have both an insulation and a sheath ?

[Tony Brooks]

20 minutes ago, Feeby100 said:

can I box this over in the gunwales ? 

Rather than box it in, why not extend the cabin side lining downwards or fit a lower lining trim that goes low enough to obscure the pipe when viewed from all normal angles. That way the BSS inspector just needs to bend down or use a mirror.

[Tracy D'arth]

6 minutes ago, Alan de Enfield said:

 

Exactly what I said.

 

How many multicore cables do you know that do not have a sheath, and how many single core cables have both an insulation and a sheath ?

Lots.  Ribbon cables are single insulated.  Lots of single core cables are double insulated. It is not what you said at all. You implied that single core cables could not be touching a gas pipe but what is correct is that cable with a single layer of insulation must not touch a gas pipe.

You want to be pedantic so get it right instead of posting misinformation. If you want an argument, clear off somewhere else I am not in the mood. Sick of your picking.

[David Mack]

23 minutes ago, BEngo said:

The gas pipe and all its fittings must be readily accessible- ie you can see it all  including joints and fittings,  without needing tools.  Clip on boxing in is OK, screwed on isn't. 

The BSS requirements is that all LPG pipe joints must be accessible for inspection. That's all. Nothing to say that they must be visible when the boat is not being inspected. And nothing referring to use of tools in this context. So screwed on boxing is OK if you have removed it beforehand for the BSS inspection.

And the requirement for accessibility for inspection only relates to joints, and not necessarily the whole pipe run. That said, having the whole pipe run visible does demonstrate that there aren't any concealed joints.

Edited June 10, 2022 by David Mack

[Alan de Enfield]

12 minutes ago, Tracy D'arth said:

Lots.  Ribbon cables are single insulated.  Lots of single core cables are double insulated. It is not what you said at all. You implied that single core cables could not be touching a gas pipe but what is correct is that cable with a single layer of insulation must not touch a gas pipe.

You want to be pedantic so get it right instead of posting misinformation. If you want an argument, clear off somewhere else I am not in the mood. Sick of your picking.

 

Yes you are correct - ribbon cable is single insulated.

I have never seen double insulated single single core on a boat - remember that there needs to be an element between the insulation and sheath, or it must be a sepa

rate covering to be classed as double insulated - having a double-thickness insulation is still a single insulation.

 

I accept that there is a difference between single insulated and single core cable.

 

 

19 minutes ago, Tracy D'arth said:

If you want an argument, clear off somewhere else I am not in the mood. Sick of your picking.

 

Pot - Kettle - check your statement on PVC cable and Polystyrene - I'm sick of your misinformation.

[Tracy D'arth]

9 minutes ago, Alan de Enfield said:

 

Yes you are correct - ribbon cable is single insulated.

I have never seen double insulated single single core on a boat - remember that there needs to be an element between the insulation and sheath, or it must be a sepa

rate covering to be classed as double insulated - having a double-thickness insulation is still a single insulation.

 

I accept that there is a difference between single insulated and single core cable.

 

 

 

Pot - Kettle - check your statement on PVC cable and Polystyrene - I'm sick of your misinformation.

I will requote what I posted  "I think the reaction of PVC and polystyrene causing problems is an canal-side myth."  including grammatical error.

 

My opinion, not a statement Mr Pedant.  

 

But I am no longer going to waste what precious time I have left arguing with an offensive person.  I suggest you consult Basec Cable Standards.

[Tony Brooks]

When electrical equipment often came packaged in expanded polystyrene I sometimes found the PVC cables had "melted" the polystyrene away from themselves but were still perfectly flexible. Also, when I relined the rear cabin of a 15 year old boat with the cables in contact with the polystyrene there were no signs of damage to either the cable or insulation, so I can see where Tracy is coming from.  I simply stuck a run of duct tape to the polystyrene and the another run to secure the cable onto the original run, so not difficult to get a barrier between the two substances. However, I don't think we should advise that running PVC cables and polystyrene  together is OK as there seems to be well documented risks of doing that in other applications.

[MtB]

17 minutes ago, Tony Brooks said:

When electrical equipment often came packaged in expanded polystyrene I sometimes found the PVC cables had "melted" the polystyrene away from themselves but were still perfectly flexible.

 

 

Which sounds like exactly the effect I see regularly too and described in my post earlier in the thread. When see it looks completely different from the photos Alan posted which leads me to wonder if there is more than one chemical reaction that can occur.

 

 

[Tony Brooks]

24 minutes ago, MtB said:

 

 

Which sounds like exactly the effect I see regularly too and described in my post earlier in the thread. When see it looks completely different from the photos Alan posted which leads me to wonder if there is more than one chemical reaction that can occur.

 

 

 

I think you may well be correct, also there are environmental considerations that may have an effect. I don't think the danger is anything like as clear-cut as some would suggest, but that does not mean that we can advise that people ignore best practice.

[Tracy D'arth]

There seems to have been considerable mission creep on this post. Its my fault, sorry. ...🤒

[MtB]

2 hours ago, Feeby100 said:

Hello I am about to run the pipe for gas to serve the hob oven and boiler alde 

now what size pipe please 

 

 

As no-one else has answered, I'll have a go. You can tie yourself in knots learning about pipe sizing but you'll probably land in needing to install 1/2" pipe,  unless you have any unusually large gas appliances or a particularly long boat.

 

Imperial fully annealed pipe is the stuff to use. Don't confuse it with 15mm half-hard rigid domestic copper pipe. 

 

 

[BEngo]

5 minutes ago, MtB said:

As no-one else has answered, I'll have a go. You can tie yourself in knots learning about pipe sizing but you'll probably land in needing to install 1/2" pipe,  unless you have any unusually large gas appliances or a particularly long boat.

Oi! 😊  See my post #5.  "Most people find 1/2 in pipe is adequate"

N

 

 

[Tracy D'arth]

8 minutes ago, MtB said:

 

 

As no-one else has answered, I'll have a go. You can tie yourself in knots learning about pipe sizing but you'll probably land in needing to install 1/2" pipe,  unless you have any unusually large gas appliances or a particularly long boat.

 

Imperial fully annealed pipe is the stuff to use. Don't confuse it with 15mm half-hard rigid domestic copper pipe. 

 

 

Table X annealed copper tube in rolls.  Or you can buy refrigeration copper tube, usually in imperial sizes.

 

With those 3 appliances most likely you will need 1/2" but maybe not all the way unless the boiler is the last appliance. It may be possible to reduce down a size towards the stern.

 

If you want to give me the input kW ratings of all 3 appliances and the length of run from the regulator/gas bottle to each appliance I will work it out for you properly.

This should be on a label on each appliance, if not, tell me the model numbers.

Are they all on the same side of the boat?

Edited June 10, 2022 by Tracy D'arth

[MtB]

6 hours ago, Tracy D'arth said:

Or you can buy refrigeration copper tube, usually in imperial sizes.

 

 

You may be able to buy it but when we last 'went down this mine' on here about ten year ago, ISTR we established the wall thickness was different and too thin except in one size, possibly 3/8" but I can't really remember.

 

Not than anyone would care (other than Alan!) 

 

 

[Alan de Enfield]

1 minute ago, MtB said:

Not than anyone would care (other than Alan!) 

 

 

Or, the fact that the specification on wall thickness has changed since that original discussion - not that you'd care.

[Feeby100]

10 hours ago, Tracy D'arth said:

Table X annealed copper tube in rolls.  Or you can buy refrigeration copper tube, usually in imperial sizes.

 

With those 3 appliances most likely you will need 1/2" but maybe not all the way unless the boiler is the last appliance. It may be possible to reduce down a size towards the stern.

 

If you want to give me the input kW ratings of all 3 appliances and the length of run from the regulator/gas bottle to each appliance I will work it out for you properly.

This should be on a label on each appliance, if not, tell me the model numbers.

Are they all on the same side of the boat?

Thank you I have not got the hob or oven yet but I find out what I am having and let you know 

the boiler is last on the run about 50ft bottle to boiler

13 hours ago, Alan de Enfield said:

 

You need to work out how much gas is used by every appliance on full power, then convert that to the size of piping needed so as to minimise pressure drop.

There are charts available to assist.

 

 

 

The gas pipe MUST be capable of being viewed over its entire length, so if you box it in you will need to make the 'boxing in' removable for the BSS inspection.

 

 

If running under the Gunwales check to make sure there are no single core cables there, as there is a minimum spacing requirement between gas piping and single core cables (Mulitcore cables that are insulated AND sheathed can be adjacent to (even clipped to) the gas piping).

 

Are you planning to have the installation 'signed off' by a Boat certified LPG Gas Fitter ?

The fact you are asking the questions may suggest that you would not necessarily comply with the definition of 'competent to instal' as is required.

I plan to have the fitter do the Connections but I run the pipe and clip it save timeConnections for a run the pipe and clip it save time

So I could just clip it on the boxing already there as will not see it under the lip of the gunwale 

so it be open to see if looking for it that’s ok 👌 

[Tony Brooks]

8 hours ago, Feeby100 said:

So I could just clip it on the boxing already there as will not see it under the lip of the gunwale 

so it be open to see if looking for it that’s ok

 

What is inside the boxing? If it is plumbing or wiring then clipping a gas pipe to it may make access to the inside more difficult. Sod's law says that the bit that needs attention will be inside the boxing.

[Feeby100]

14 hours ago, Tony Brooks said:

 

What is inside the boxing? If it is plumbing or wiring then clipping a gas pipe to it may make access to the inside more difficult. Sod's law says that the bit that needs attention will be inside the boxing.

There is noting in the boxing so I can clips it on it I guess I spoke to a Expert gas engineer and he said 15 mil copper coil plastic coated

[Alan de Enfield]

28 minutes ago, Feeby100 said:

I spoke to a Expert gas engineer

 

That doesn't sound like a Boat qualified LPG qualified gas fitter.

 

Have you confirmed he is correctly qualified for boat installations ?

 

Your piping and the installation should be done to ISO 10239  ask him "does the plastic coated pipe comply and do you install in compliance with ISO 10239 ?"

 

 

 

 

 

 

 

Don't forget that you need to work out the pressure drop which depends on appliance and distance - you also need to add additional 'length' for each resistance (connector and / or bend) as per the table below :

 

 

 

Edited June 11, 2022 by Alan de Enfield

[MtB]

31 minutes ago, Feeby100 said:

I spoke to a Expert gas engineer and he said 15 mil copper coil plastic coated

 

 

Lol he was winding you up! 

 

Did you check his Gas Safe Register ID card showed him as qualified to work on LPG on boats?