90 degree bends in LPG rigid copper pipe

[Bronkristian]

Hi all,

 

We are installing an LPG system for a wide beam and we need to know if 90 degree bends in the rigid copper pipe are bss compliant. We will need approx 2 bends as the pipe will run along the floor and need to go up the bulkhead and an interior wall. I see bss states having no more than necessary elbows and other joints but nothing apecifically about bends. Can anyone help please?

[dor]

Bends are ok. Don't try and get the radius too tight. You can get bending springs to do it neatly without risking the pipe kinking. Small diameter pipes the spring goes on the outside.

[MtB]

What rigid copper is that then?

 

You're supposed to be using annealed copper tube in a boat.

By the way, welcome to the forum!!

(But to answer your question, provided you are using annealed copper not 'half-hard' domestic tube, then bends in the pipe are fine from a BSS point of view.)

[gazza]

http://www.toolstation.com/shop/Hand+Tools/d10/Pipe+Cutting+%26+Bending/sd2996/Draper+Mini+Tube+Pipe+Bender/p50190

 

get yourself one of these.

 

i have just re positioned our fuel tank, needed a couple of bends in some 8mm pipe, almost as cheap as a couple of 90 elbows.

it will do 1/4" ok as well

[Neil Smith]

I bought a cheap mini pipe bender on ebay for a few quid, did the bends in my 10mm gas pipe easily.

 

Neil

[BMC problems]

I've never needed tools to bend thick-walled* drawn pipe

 

*imperial size

 

Hands and a suitable former will do the trick.

[MtB]

I've never needed tools to bend thick-walled* drawn pipe

 

*imperial size

 

Hands and a suitable former will do the trick.

 

 

We're getting off topic. The OP wants to know if bending his 'rigid pipe' contravene the BSS.

[BMC problems]

true.

[MtB]

Which it doesn't, but various other things he mentions doing in his post are well dodgy!

[Dave Payne]

Which it doesn't, but various other things he mentions doing in his post are well dodgy!

 

 

Various?

[MtB]

 

 

Various?

 

 

Yes. He mentions 1) using 'rigid copper' and 2) running the pipe at floor level. Both appallingly bad practice contravening PD 5482 - 2005 part III (gas for boats).

 

Possibly contravening BSS although perhaps not, as BSS is astonishingly slack on certain aspects of gas. These two points being examples if not in the BSS.

 

I certainly know of one 20 year old boat gas-plumbed with rigid 15mm domestic copper pipe regularly passing BSS throughout its life, to my surprise.

Edited April 12, 2016 by Mike the Boilerman

[Dave Payne]

What is the difference in those two pipes?

[Alan de Enfield]

 

 

......BSS is astonishingly slack................

 

I had never realised that if you were not using* your boat on EA waters (Thames & Medway) that you could apply for a BSS exemption until you started using it again

 

*i.e it is on their waters but 'not in use'.

 

"Application for exemption from requirement to pass boat safety scheme examination".

 

There is an 'application' form on the Gov.UK website.

[WotEver]

What is the difference in those two pipes?

I believe that the boaty stuff is both thicker walled and also annealed which will make it less prone to work hardening and splitting.

 

If I'm wrong I'm sure someone will tell me pretty quickly ?

 

Tony

http://www.toolstation.com/shop/Hand+Tools/d10/Pipe+Cutting+%26+Bending/sd2996/Draper+Mini+Tube+Pipe+Bender/p50190

 

get yourself one of these.

Oops, according to the blurb that Bender "Cuts 8, 10 and 12 O/D soft copper tubes..." Naughty Bender ?

[MtB]

I believe that the boaty stuff is both thicker walled and also annealed which will make it less prone to work hardening and splitting.

 

If I'm wrong I'm sure someone will tell me pretty quickly

 

 

No, this is broadly right.

 

Half-hard copper domestic gas is fully rigid and self-supporting. Annealed gas pipe is soft and floppy, and won't self-support in lengths of more than about two feet. 'Boat standard' gas pipe is also only available in imperial in sizes (with one exception) as it is thicker-walled than metric annealed pipe, and the metric is too thin-walled to meet the standard I've forgotten the name of

[gazza]

I believe that the boaty stuff is both thicker walled and also annealed which will make it less prone to work hardening and splitting.

 

If I'm wrong I'm sure someone will tell me pretty quickly ?

 

Tony

 

Oops, according to the blurb that Bender "Cuts 8, 10 and 12 O/D soft copper tubes..." Naughty Bender ?

Well spotted! Good old Toolstation, I shall wind up my brother in law, he works for parent company Travis Perkins, standards are slipping since they took over Edited April 12, 2016 by gazza

[MtB]

Oops, according to the blurb that Bender "Cuts 8, 10 and 12 O/D soft copper tubes..." Naughty Bender

 

 

 

Not suitable for installing boat gas then, except for 8mm which is near as dammit 5/16"

[WotEver]

Not suitable for installing boat gas then, except for 8mm which is near as dammit 5/16"

Gazza reckons it does 1/4" OK.

 

Tony

[gazza]

Not suitable for installing boat gas then, except for 8mm which is near as dammit 5/16"

Gazza reckons it does 1/4" OK.

Tony

My leak off rail return to tank is 1/4" did that spot on on the 8mm former.

 

Mike, absolutely no reason 3/8" won't work in the 10mm former.

12mm former may slightly deform 1/2" though.

[nicknorman]

Does gas pipe actually have to be that thick-walled? It is surely only running at less than 1 bar. I just plumbed an oxygen system into my glider. The cylinder and pipe work runs at 200 bar (3000psi) but the walls of the approved copper pipe (3/16th") don't look thick.

 

So just why does boaty copper gas pipe have to be so thick-walled?

Edited April 12, 2016 by nicknorman

[MtB]

Does gas pipe actually have to be that thick-walled?

 

Yes it does, if the installation is to comply with PD 5482-2005 part 3.

 

If you don't care about complying with that (it's only mandatory for RCD) then a BSS bod probably won't be bothered as I don't think wall thickness is mandated in the BSS.

 

Whether thick walling is a Good Idea technically is a whole nother discussion!

 

 

 

 

(Edit to remove the spurious word.)

Edited April 12, 2016 by Mike the Boilerman

[nicknorman]

Yes it does, if the installation is to comply with PD 5482-2005 part 3.

 

If you don't care about complying with that (it's only mandatory for RCD) then a BSS bod probably won't be bothered as I don't think wall thickness is mandated in the BSS.

 

Whether thick walling is a Good Idea technically is a whole nother discussion!

 

(Edit to remove the spurious word.)

But that is my question - why does PD 5482-2005 part 3 require a pipe whose thickness can withstand many orders of magnitude higher pressure than it will encounter?

[MtB]

But that is my question - why does PD 5482-2005 part 3 require a pipe whose thickness can withstand many orders of magnitude higher pressure than it will encounter?

 

 

I don't actually know but I could speculate and dream up whole sheafs of possible reasons. That's all it would be though. Speculation.

 

I think the truth lies in what someone wrote in another thread earlier today:

 

Ok so first of all on the regulations, one can argue that this particular bit of this regulation isn't necessary in this particular circumstance, but that is what is generally called "re-inventing the wheel". There is a danger that a factor is overlooked and so it is better and simpler and usually not difficult just to go along with the regulation.

Wise words, don'tcher think?

[nicknorman]

I don't actually know but I could speculate and dream up whole sheafs of possible reasons. That's all it would be though. Speculation.

 

I think the truth lies in what someone wrote in another thread earlier today:

 

Ok so first of all on the regulations, one can argue that this particular bit of this regulation isn't necessary in this particular circumstance, but that is what is generally called "re-inventing the wheel". There is a danger that a factor is overlooked and so it is better and simpler and usually not difficult just to go along with the regulation.

However I am not suggesting ignoring the regulation. I am merely curious as to the rationale behind the regulation. There is an important difference. Just interested, as having plumbed the oxygen system, kit of parts being supplied by a reputable manufacturer of oxy systems for aircraft, I wondered why the 3/16th main supply pipe was hard copper whilst the 1/8th pipe to the contents/pressure gauge was soft copper. It all runs at up to 200 bar. Perhaps just what they had in stock? None of it looked particularly strong but clearly with the small diameter (F=PxA) it can take 200bar with a large safety margin.

[MtB]

Oddly, the rationale for all gas regulation is kept a deathly secret from us gas bods. Always irritates me. We are just told to comply in order to have a defence against prosecution.

 

When I was a teenager we used to be able to buy DIY brake pipe kits for our cars. 3/16" o/d copper tube IIRC, about 3/32" bore. Never looked strong enough for brake line pressures but it was!