Gas piping sizes

[DeanS]

Hello I'd like to order some gas piping and fittings for the new widebeam.

 

Would it be correct to run 3/8 Imperial piping from the gas bottle, and to each appliance. Shall I step it down to 1/4 Imperial at all at any point? I'll fit isolators on each branch, and a test point at the furthest point.

 

Boat is reverse layout, so gas bottles in bow...supply run to Morco heater in shower/toilet room...and then further along to supply the kitchen appliances..which are near the stern...a distance of about 12metres from bow to stern galley.

 

Found this supplier.

[dor]

I would run in 1/2" and go to 3/8" on the appliance tees.

[the grinch]

it depends on length of pipe runs and the total KWhr of the total load attached to each section

 

A-B (gas bottles to first tee)

B-C (first leg after tee)

C-D (second leg after tee)

D-E (firts leg after second tee)

 

and so on, what you ideally want is an equal %age pressure drop in each section and a minimum drop from bottle to each appliance.

 

for a better sizing then provide a detailed description of load attached, distance etc and remember an elbow is equal to ½ a metre of pipe

[ditchcrawler]

Maybe you should read this thread and see some of the comments there about doing your own gas installation

[bizzard]

Ideally, if pressure to all appliances is to remain equal no matter what and where appliances are turned on or off a ring main is the answer, same as electricity, water,air ect circuits. But a large bore main line like 1/2 with teeing off points on these kind and size of boats is usually quite adequate of course.

[larkshall]

Ideally, if pressure to all appliances is to remain equal no matter what and where appliances are turned on or off a ring main is the answer, same as electricity, water,air ect circuits. But a large bore main line like 1/2 with teeing off points on these kind and size of boats is usually quite adequate of course.

 

 

I agree, use 28mm, main feed teeing off to each appliance at 22mm. or further reduction as required.

[bizzard]

I agree, use 28mm, main feed teeing off to each appliance at 22mm. or further reduction as required.

Bly me, do you mean for a gas fired power station.

[DeanS]

it depends on length of pipe runs and the total KWhr of the total load attached to each section

 

A-B (gas bottles to first tee)

B-C (first leg after tee)

C-D (second leg after tee)

D-E (firts leg after second tee)

 

and so on, what you ideally want is an equal %age pressure drop in each section and a minimum drop from bottle to each appliance.

 

for a better sizing then provide a detailed description of load attached, distance etc and remember an elbow is equal to ½ a metre of pipe

 

 

The gas line will be run down one side of the boat. The first T is to supply a Morco heater. The end of the line supplies a gas cooker. That's all I'll need to install. The distance from bottles to Morco is 3metres, and the cooker is an additional 9metres further. (as shown below)

 

A-B (gas bottles to first tee) - 3metres (

B-C (first leg after tee) - 9metres

 

I would prefer to standardise 3/8 all the way through...and based on the simplicity of this installation, and what I've seen on other boats...I guess this would work fine? I think 1/2" may be slight overkill...as someone mentioned..the connection at the gas regulator is quite small?

[larkshall]

Bly me, do you mean for a gas fired power station.

 

 

No have a 5 burner hob (inc wok burner), double gas oven, and an Alde boiler. Its on a barge though, not a NB, pipework is probably 60 feet in total.

[bizzard]

I have a 3/8'' main line, A small two burner cooker with oven and grill, a Paloma water heater and a gas fridge which all work well. So for your length of boat and pipe run i'd say a 1/2'' main line would be sufficient.

[DeanS]

Does anyone know the best/best priced supplier of 1/2" and 3/8" gas piping and fittings. The supplier link I put above didn't seem to supply 1/2".

[bizzard]

Does anyone know the best/best priced supplier of 1/2" and 3/8" gas piping and fittings. The supplier link I put above didn't seem to supply 1/2".

Try B.E.S.

[smileypete]

The gas line will be run down one side of the boat. The first T is to supply a Morco heater. The end of the line supplies a gas cooker. That's all I'll need to install. The distance from bottles to Morco is 3metres, and the cooker is an additional 9metres further. (as shown below)

 

A-B (gas bottles to first tee) - 3metres (

B-C (first leg after tee) - 9metres

 

I would prefer to standardise 3/8 all the way through...and based on the simplicity of this installation, and what I've seen on other boats...I guess this would work fine? I think 1/2" may be slight overkill...as someone mentioned..the connection at the gas regulator is quite small?

Probably best to do separate runs in 3/8 to galley and Morco, as compliant 1/2" pipe is tres expensive. BES Gas and Plumbing do 3/8" 21SWG pipe in the refrigeration section which is compliant.

 

Probably worth trawling the search facility for past threads on gas pipe sizing, thickness, compression fittings and olives, gas locker design. BES do a lot of the bits you'll need.

 

Try and do the pressure drop calculations for the galley and Morco, the Morco should be OK but the run to the galley may be a bit borderline depending on what you're running there.

 

cheers, Pete.

~smpt~

Edited July 25, 2012 by smileypete

[DeanS]

Probably best to do separate runs in 3/8 to galley and Morco, as compliant 1/2" pipe is tres expensive. BES Gas and Plumbing do 3/8" 21SWG pipe in the refrigeration section which is compliant.

 

Probably worth trawling the search facility for past threads on gas pipe sizing, thickness, compression fittings and olives, gas locker design. BES do a lot of the bits you'll need.

 

Try and do the pressure drop calculations for the galley and Morco, the Morco should be OK but the run to the galley may be a bit borderline depending on what you're running there.

 

cheers, Pete.

~smpt~

 

To do this, would I Tee off at the source ...and run 2 lengths of 3/8" ?

 

 

It seems easier to source the 3/8" pipe and fittings, than 1/2", so I'd be keen to run 2 seperate 3/8" lines...one would be 3metres for hot water heater. The other would be a full 12m to galley oven.

[bizzard]

To do this, would I Tee off at the source ...and run 2 lengths of 3/8" ?

 

 

It seems easier to source the 3/8" pipe and fittings, than 1/2", so I'd be keen to run 2 seperate 3/8" lines...one would be 3metres for hot water heater. The other would be a full 12m to galley oven.

If you can tee off at the regulator for two 3/8 pipes, join up the other two ends and you have a ring main, couldn't be better.

From a large capacity regulator with large outlet port that is.

Edited July 25, 2012 by bizzard

[alan_fincher]

Probably best to do separate runs in 3/8 to galley and Morco, as compliant 1/2" pipe is tres expensive. BES Gas and Plumbing do 3/8" 21SWG pipe in the refrigeration

Why then do they say of the pipe in that section

 

NOTE: THESE TUBES AND COILS ARE SPECIFICALLY FOR USE IN REFRIGERATION. FOR PLUMBING TUBES AND COILS PLEASE CLICK HERE.

 

The refrigeration pipe is £67-28 + VAT for 30m, whereas the stuff sold specific to gas is either £100-71 or £110.84 + VAT for 30M, (depends on gauge you choose).

 

So if the refrigeration pipe is OK, why is it so much cheaper than the gas stuff ?

 

However, whichever way you go, at BES 1/2" pipe is only about 50% more expensive than equivalent 3/8", so, on that basis, two runs of 3/8" would actually cost more than buying one run of 1/2" of same length.

 

...............Except of course it seems to be sold by the roll - rather than by the metre - in this case it may well be worth finding someone selling "by the metre" to only buy what you need.

[smileypete]

Why then do they say of the pipe in that section

 

The refrigeration pipe is £67-28 + VAT for 30m, whereas the stuff sold specific to gas is either £100-71 or £110.84 + VAT for 30M, (depends on gauge you choose).

 

So if the refrigeration pipe is OK, why is it so much cheaper than the gas stuff ?

 

However, whichever way you go, at BES 1/2" pipe is only about 50% more expensive than equivalent 3/8", so, on that basis, two runs of 3/8" would actually cost more than buying one run of 1/2" of same length.

 

...............Except of course it seems to be sold by the roll - rather than by the metre - in this case it may well be worth finding someone selling "by the metre" to only buy what you need.

Have a look at this post explaining the pipe thickness requirements:

 

http://www.canalworld.net/forums/index.php?showtopic=46609&view=findpost&p=864208

 

Why is the refrigeration pipe cheaper? Probably 'cause it's made and sold in much greater volumes. I've got no doubts it's fit for purpose, some refrigerants will run up to 700x the 37mbar pressure of LPG.

 

Edit: Quite like Bizzards idea of making 2 runs joined at the end to form a ring, if Dean ends up needing more than 15m or less pressure drop that would be the way to go.

 

cheers, Pete.

~smpt~

Edited July 25, 2012 by smileypete

[alan_fincher]

I've got no doubts it's fit for purpose.............

Yes but "fit for purpose" doesn't necessarily equal "compliant", which was the word you used first.

 

It may well be "compliant" too, but there have been an awful lot of cases where people with access to relevant documentation have shown things that look like they should be not always are.

 

I wonder if any of the GasSafe LPG registered people on the forum are prepared to confirm the view that refrigeration pipe fully meets all the requirements.

 

(Note - I'm not saying it doesn't - just asking the question!)

[bowten]

Dean,how about a separate gas bottle and gas pipe run for your morco.

[the grinch]

you still haven't told us the gross or nett max output of the appliances as you maty not require large diameter pipework if the pressure drops are sufficiently low enough to use the smaller diameter.

i will happily work it out if you give me the rates for the 2 appliances.

 

I agree, use 28mm, main feed teeing off to each appliance at 22mm. or further reduction as required.

 

and this why DIYing is dangerous as the sizes are domestic copper not LPG rated!

 

Dean,how about a separate gas bottle and gas pipe run for your morco.

 

so thats 2 by regulators 2 x test point, 2 x pig tail sets and 2 full tests by the examiner every time your BSS is due. end result a very expensive way of doing things

[the grinch]

refridgeration pipe is NOT suitable for the conveyance of gaseous liquids on boats as it is Half hard copper not soft copper and are specified as ONLY suitable for refridgeration use (see P.76 of the BES catalogue)

 

Probably best to do separate runs in 3/8 to galley and Morco, as compliant 1/2" pipe is tres expensive. BES Gas and Plumbing do 3/8" 21SWG pipe in the refrigeration section which is compliant.

 

cheers, Pete.

~smpt~

 

no they don't as it isn't please read above post.

[smileypete]

refridgeration pipe is NOT suitable for the conveyance of gaseous liquids on boats as it is Half hard copper not soft copper and are specified as ONLY suitable for refridgeration use (see P.76 of the BES catalogue)

 

"Refrigeration quality seamless copper tubes and coils, dehydrated, cleaned (degreased) capped and plugged. Annealed to half hard (straight lengths) and soft (coils). Manufactured to BS EN 1057 (BS 2871 : Part 2 : 1972), ASTM B280, DIN 1754/8905. All dimensions refer to outside diameter."

 

There you go, just buy the coils, not the straights. Would have thought that's pretty obvious...

 

cheers, Pete.

~smpt~

 

Yes but "fit for purpose" doesn't necessarily equal "compliant", which was the word you used first.

The wall thickness of the 3/8" refrigeration coil is compliant.

 

cheers, Pete.

~smpt~

[the grinch]

pretty obvious that you can't read as it is in Black Bold PrintTHESE TUBES AND COILS ARE SPECIFICALLY FOR USE IN REFRIGERATION The sooner they make it impossible to fit stuff that people have no idea on (or worse think they know it) the better.

[smileypete]

pretty obvious that you can't read as it is in Black Bold PrintTHESE TUBES AND COILS ARE SPECIFICALLY FOR USE IN REFRIGERATION The sooner they make it impossible to fit stuff that people have no idea on (or worse think they know it) the better.

OK so you accept the coiled tube is soft copper, not half hard, right? Now, it IS specifically for refrigeration, and the reason WHY, is because it's:

 

"dehydrated, cleaned (degreased) capped and plugged"

 

and for NO other reason. That doesn't make it unsuitable for gas, does it? It's compliant thickness, annealed soft copper, and made to BS EN 1057. Why specifically then would it not be suitable for gas?

 

cheers, Pete.

~smpt~

[alan_fincher]

Call me cautious, but if a supplier says (in capitals) a pipe is specifically for a completely unrelated purpose, and directs you to a different page if your use is not refrigeration, I'm not sure it would necessarily make it my first choice for LPG on boats.

 

Still a better choice than the 28mm and 22mm water plumbing suggested elsewhere in the thread though, I must admit!