3/8 or 10mm gas pipe??

[Chas78]

Hi All,

I am about to replace the old gas pipe in my boat as it has many joints in the system i am being told i have to use 3/8 copper pipe as there will be two appliances ie a cooker and water heater could i use 10mm pipe and will this satisfy the boat inspector? it seems very difficult to find 3/8 pipe where as 10mm can be bought nearly everywhere any advice very much appreciated thanks in advance 

[Murflynn]

I've had this discussion several times including with gas fitters who were buying kit in the local chandlery.  

10mm pipe and 3/8 gas service compression fittings seems to be the norm. 

how will the boat inspector know if you have used 10mm or 3/8 (as if it matters)? 

the RCD requires a specific minimum wall thickness, which is not met by the usually available 10mm pipe, but is not checked in BSS.

Edited January 25, 2018 by Murflynn

[Robbo]

ASAP do both 10mm and 3/8" and all the relevant fittings..

https:// www. asap-supplies.com/hose/copper-nylon-piping/diameter/10mm-3/8%22/primary-construction/copper

 

 

*edit by request of supplier, who informs us the updated location of this page is as follows: 

https://www.asap-supplies.com/hose/copper-nylon-tubing

 

Edited November 22, 2021 by DHutch
link update

[alan_fincher]

27 minutes ago, Murflynn said:

10mm pipe and 3/8 gas service compression fittings seems to be the norm.

Really - how does that work then?

3/8" olives are closer to 9.5mm - if the parts are properly manufactured surely you have no chance of forcing a 3/8" olive on to a 10mm pipe?

This sounds plain wrong, and poor advice.

I know people try to go the other way, (10mm compression on 3/8" pipe), but the 0.5mm slack that exists before tightening I understand makes that highly risky.

I don't think you can ever safely mix 3/8" imperial with 10mm metric

(Although 5/16" and 8mm are probably close enough that it is fine in that case - perhaps you are getting confused with that?)

Edited January 25, 2018 by alan_fincher

[Chas78]

9 minutes ago, alan_fincher said:

Really - how does that work then?

3/8" olives are closer to 9.5mm - if the parts are properly manufactured surely you have no chance of forcing a 3/8" olive on to a 10mm pipe?

This sounds plain wrong, and poor advice.

I know people try to go the other way, (10mm compression on 3/8" pipe), but the 0.5mm slack that exists before tightening I understand makes that highly risky.

I don't think you can ever safely mix 3/8" imperial with 10mm metric

(Although 5/16" and 8mm are probably close enough that it is fine in that case - perhaps you are getting confused with that?)

Dont want to do the risky bit so its 3/8 end of as i did initially fit 8mm which i had to rip out due to not exceptable 

 

[Tonka]

how old is the gas. if it is imperial gas how will it fit in a metric pipe

[OldGoat]

6 minutes ago, Tonka said:

how old is the gas. if it is imperial gas how will it fit in a metric pipe

Oy! - That's Bizzard's territory........

[Chas78]

I ask a serious question hoping to get some sensible answers which i initially did thank you  but now we have the boredom sector joining in if its not a constructive sensible answer/comment don't bother replying  

[WotEver]

5 minutes ago, Chas78 said:

I ask a serious question hoping to get some sensible answers which i initially did thank you  but now we have the boredom sector joining in if its not a constructive sensible answer/comment don't bother replying  

Ooh, temper, temper.

10mm pipe generally doesn’t meet the required minimal wall thickness. Neither does it fit 3/8” fittings. Therefore 3/8” is the way to go as you were initially told. 

[Guest]

10 minutes ago, Chas78 said:

I ask a serious question hoping to get some sensible answers which i initially did thank you  but now we have the boredom sector joining in if its not a constructive sensible answer/comment don't bother replying  

Chill out man!
Our boat is piped in 3/8"  which I know was still available at Midland Chandlers (cue comments) late last summer. We did, however, have to use an adapter to connect to the new cooker which was a metric fitting.
I do remember being given some 10mm pipe that was left over from another boat a few years back and it was awful stuff to bend when it kinked very easily whereas the 3/8" was dead easy. 

 

[Tonka]

29 minutes ago, Chas78 said:

I ask a serious question hoping to get some sensible answers which i initially did thank you  but now we have the boredom sector joining in if its not a constructive sensible answer/comment don't bother replying  

Chill out and learn how to google https://www.bes.co.uk/search/?q=3%2F8+copper+pipe

[Johny London]

As I understand this, using the metric pipe with the thinner wall, it can crush when you tighten the joins, thus never being properly sealed. I was told that by the marine gas engineer that did mine. So, the imperial it is, in this case.

[bizzard]

1 hour ago, Tonka said:

how old is the gas. if it is imperial gas how will it fit in a metric pipe

Metric gas. KG on the bottle.

[LadyG]

1 hour ago, Tonka said:

Chill out and learn how to google https://www.bes.co.uk/search/?q=3%2F8+copper+pipe

But that is  refrigerator quality, my thinking is I want the best for the job. So could there possibly be some guidance on what to fit, to where, and by whom.

PS to OP, you'v been on this forum long enough to know that you are likely going to get some "off the wall" comments, its the oil  that keeps the forum going.

A definitive answer will be provided by your gas fitter: as I read it you should/may need to/have to renew the BSC after significant work.

Alde Bubble testers are sold for 8 or 10mm, how does that work? HOW NOT TO DO IT:-

 

Edited January 25, 2018 by LadyG

[WotEver]

50 minutes ago, Tonka said:

Chill out and learn how to google https://www.bes.co.uk/search/?q=3%2F8+copper+pipe

I love how it’s sold by the metre

[WotEver]

28 minutes ago, LadyG said:

But that is  refrigerator quality, my thinking is I want the best for the job. So could there possibly be some guidance on what to fit, to where, and by whom.

Why do you suppose that refrigeration Quality would be inferior? It complies with BS EN 12735-1 which states solid drawn (seamless) with a minimum wall thickness of 0.8mm. That’s exactly what the BSS specifies. 

30 minutes ago, LadyG said:

Alde Bubble testers are sold for 8 or 10mm, how does that work?

You change the fittings for 3/8”

[LadyG]

21 minutes ago, WotEver said:

Why do you suppose that refrigeration Quality would be inferior? It complies with BS EN 12735-1 which states solid drawn (seamless) with a minimum wall thickness of 0.8mm. That’s exactly what the BSS specifies. 

You change the fittings for 3/8”

If Alde were happy about mixing fittings [and they are  NOT], they would sell the fittings as a kit. The whole idea is to make the system safer, not just to appear to comply if the inspector [erroneously] ticks a box.

[system 4-50]

I used 3/8th pipe (from Socal) with a 10mm olive to connect the Morco which (mine) has a nice combined valve to 10mm fitting (avail from Midland Chandlers) . No problems. Easy to do and tested as ok.  

I used bubble testers from Socal who fit 3/8th adapters for you which is hard to do yourself. 

[LadyG]

52 minutes ago, system 4-50 said:

 

I used bubble testers from Socal who fit 3/8th adapters for you which is hard to do yourself. 

Now we are getting to the nitty gritty: the Question is can Socal issue a Certificate to ISO standards, what I am saying is, are these a one off job, or manufactured with QA etc etc.

Edited January 25, 2018 by LadyG

[Alan de Enfield]

41 minutes ago, WotEver said:

Why do you suppose that refrigeration Quality would be inferior? It complies with BS EN 12735-1 which states solid drawn (seamless) with a minimum wall thickness of 0.8mm. That’s exactly what the BSS specifies. 

You change the fittings for 3/8”

Unless I have missed something, both the BSS (in section 7) and the RCD refer to :

ISO 10239:2008(E) "Small craft — Liquefied petroleum gas (LPG) systems

6.2 Piping
6.2.1 Only solid drawn copper or drawn stainless steel piping, which are galvanically compatible, shall be
used for rigid supply lines. Wall thickness for piping shall be greater than 0,8 mm for piping up to 12 mm
outside diameter and a minimum of 1,5 mm for an outside diameter greater than 12 mm.
6.2.2 There shall be no joints or fittings in piping passing through engine compartments.
6.2.3 Metallic LPG supply piping routed through engine compartments shall be protected by conduit or
trunking, or supported by non-abrasive attachments which are no more than 300 mm apart.
6.2.4 Fittings for connections and joints in piping shall be metallic and of any of the following types:
⎯ hard soldered connections;
⎯ cutting ring fittings in accordance with ISO 8434-1:2007, Table 4 (see also 6.4.2, 6.4.4, 6.4.5);
⎯ copper rings on copper piping; stainless steel rings on stainless steel piping;
⎯ connections in accordance with EN 560.
Jointing compound for flared fittings or flared rings shall not be used.

[system 4-50]

7 minutes ago, LadyG said:

Now we are getting to the nity gritty: the Question is can Socal issue a Certificate to ISO standards, what I am saying is, are these a one off job, or manufactured with QA etc etc.

Good Grief!!!! Life's too short.

[bizzard]

1 hour ago, WotEver said:

I love how it’s sold by the metre

Be jez

[LadyG]

33 minutes ago, system 4-50 said:

Good Grief!!!! Life's too short.

Yes, that's from six months as  QA in a ISO 9001 environment, manufacturing pressure gauges, it was kinda important we got it right, as this is.

Edited January 25, 2018 by LadyG

[Chas78]

Thanks for all the advice very much appreciated so its 3/8 all the way and now to my next question where do i buy the 3/8 fittings to convert the Alde Bubble Tester to imperial and whats part number? 

[system 4-50]

I am going to sue my parents.

When I was born, they had no documented quality policy, quality management system scope, or quality objectives pertaining to my existence . No risk assessment was done and very few records were kept about me. No forest was cut down.   They didn't determine the internal and external issues relevant to my purpose and strategic direction.  They didn't demonstrate how the standard's requirements were being met, and no auditor was called upon to determine the quality management system's effectiveness. It is a wonder that I have survived at all.

In my professional career standards were just an extra burden on those who were trying to make something that worked correctly and never added anything useful but occasionally distracted people from doing their proper job correctly.

8 minutes ago, Chas78 said:

Thanks for all the advice very much appreciated so its 3/8 all the way and now to my next question where do i buy the 3/8 fittings to convert the Alde Bubble Tester to imperial and whats part number? 

Ask Socal?