More on gas fittings.

[Nicholas123]

I thought so as well, but perhaps it's an 8mm to male parallel thread elbow with a flange...

[Later] In fact exactly like the one David links to in #11.

Either way, I can't find anything to replace it in brass.

Whatever it is Nigel it looks perfectly sound to me.I'd just give it a light wire brush & rub some diesel in or maybe a better idea would be to give it a coat of Vaseline,job done.

 

[vyv_cox]

I'm not keen on brass because it age hardens & can become brittle.

???? No metal that I know of age hardens without some other input. Age hardening is a complex, three-stage heat treatment process applicable to precipitation hardening alloys. Brass is not one of them. I have some brass fittings that are probably 100 years old. Not hard or brittle.

 

[Nicholas123]

???? No metal that I know of age hardens without some other input. Age hardening is a complex, three-stage heat treatment process applicable to precipitation hardening alloys. Brass is not one of them. I have some brass fittings that are probably 100 years old. Not hard or brittle.

I've had any number of brass screws crumble away to nothing in no time & if you try to bend brass without first annealing it it invariably cracks so I'd rather not go anywhere near it.As for making seacocks out of it that seems plain bonkers.....each to his own.

 

[vyv_cox]

I've had any number of brass screws crumble away to nothing in no time & if you try to bend brass without first annealing it it invariably cracks so I'd rather not go anywhere near it.As for making seacocks out of it that seems plain bonkers.....each to his own.

Brass screws commonly fail due to dezincification, as will any 60/40 brass exposed to seawater or 'soft' fresh water. 60/40 brass is a casting alloy, not designed to be bent. 70/30 will bend perfectly well - that is the grade supplied in sheet, wire and tubing form.

 

[Nicholas123]

Brass screws commonly fail due to dezincification, as will any 60/40 brass exposed to seawater or 'soft' fresh water. 60/40 brass is a casting alloy, not designed to be bent. 70/30 will bend perfectly well - that is the grade supplied in sheet, wire and tubing form.

I tend to make stuff from a collection of 'bits' I have accumulated be it brass copper stainless you name it & I find that it bends best when annealed is that not age hardening?
I take your point about "dezincification" though I believe we used to call it electrolytic action.Why anyone opts for brass as opposed to bronze is completely beyond me.I have the original Blakes seacocks on my boat & am damn glad they are there......please don't tell me if they have now been found to be dodgy

 

[Tranona]

I tend to make stuff from a collection of 'bits' I have accumulated be it brass copper stainless you name it & I find that it bends best when annealed is that not age hardening?
I take your point about "dezincification" though I believe we used to call it electrolytic action.Why anyone opts for brass as opposed to bronze is completely beyond me.I have the original Blakes seacocks on my boat & am damn glad they are there......please don't tell me if they have now been found to be dodgy

You are getting very confused here. All the materials have a place in specific applications. Bronze is indeed superior for use in under(sea)water situations as it does not contain zinc. However, it is very expensive and there are alternatives available. The most common for underwater fittings such as seacocks and skin fittings is DZR which is a modified brass that does not suffer from dezincification. Blakes seacocks have been made from DZR for many years. Plain brass is less satisfactory because of the potential for dezincification, but it is cheap and commonly used in fuel systems and fresh water systems. Brass screws will dezincify when used in wood, particularly in damp environments. Brass is also used for gas fittings because it does not corrode in the same way as steel, although corrosion in steel fittings is mainly cosmetic. However, corrosion does become a problem with steel when used externally, for example in damp gas lockers. Many boats have the gas bottles in the anchor locker or exposed lockers in the cockpit - and I can assure you they can corrode to the point where you cannot undo them, for example the lock nut of a bulkhead fitting. So all the mild steel gas fittings on my boat have been replaced with brass.

 

[nigelmercier]

Well, it works on my boat which is exactly the same original fitting as yours...

So would you say it was one of these?
http://www.ebay.co.uk/itm/151027296590 as linked by David in #11?

 

[Tranona]

So would you say it was one of these?
http://www.ebay.co.uk/itm/151027296590 as linked by David in #11?

Looks similar but not exactly the same. When I started to install my new hose and cooker I bought a steel fitting from a specialist in motor caravans - many caravans are made in Germany and use those fittings. I could not get it to seal so decided to have the whole lot replaced. The fitter used (as far as I can tell) the two Wade fittings from the BES catalogue referred to earlier.

 

[nigelmercier]

The fitter used (as far as I can tell) the two Wade fittings from the BES catalogue referred to earlier.

I don't see how these would work, do you mean there is a short bit of copper between them?

 

[Nicholas123]

You are getting very confused here. All the materials have a place in specific applications. Bronze is indeed superior for use in under(sea)water situations as it does not contain zinc. However, it is very expensive and there are alternatives available. The most common for underwater fittings such as seacocks and skin fittings is DZR which is a modified brass that does not suffer from dezincification. Blakes seacocks have been made from DZR for many years. Plain brass is less satisfactory because of the potential for dezincification, but it is cheap and commonly used in fuel systems and fresh water systems. Brass screws will dezincify when used in wood, particularly in damp environments. Brass is also used for gas fittings because it does not corrode in the same way as steel, although corrosion in steel fittings is mainly cosmetic. However, corrosion does become a problem with steel when used externally, for example in damp gas lockers. Many boats have the gas bottles in the anchor locker or exposed lockers in the cockpit - and I can assure you they can corrode to the point where you cannot undo them, for example the lock nut of a bulkhead fitting. So all the mild steel gas fittings on my boat have been replaced with brass.

I am not confused at all.I can not see the justification for many of the brass fittings now being used quite commonly on boats when the difference between brass & bronze is not that much nor would I recommend mild steel for exposed conditions but that fitting of Nigel's does look like it would be perfectly adequate with a bit of attention.To say that mild steel is not suitable in all conditions (like inside a cabin) is clearly scaremongering (in my humble opinion of course)

 

[Tranona]

I am not confused at all.I can not see the justification for many of the brass fittings now being used quite commonly on boats when the difference between brass & bronze is not that much nor would I recommend mild steel for exposed conditions but that fitting of Nigel's does look like it would be perfectly adequate with a bit of attention.To say that mild steel is not suitable in all conditions (like inside a cabin) is clearly scaremongering (in my humble opinion of course)

Suggest you look at the prices of bronze fittings compared with brass before making such statements! Examples 3/4" skin fitting brass £8, bronze £13 ; 3/4" ball valve brass £5, bronze £17, DZR £11.

That is not the case with mild steel and brass for gas fittings as they are very similar in price so cannot understand why you would use steel. And I did not say steel was not suitable for interior, although would you really want that load of rust when you can have a fitting that does not corrode?

 

[Tranona]

I don't see how these would work, do you mean there is a short bit of copper between them?

Pretty sure the straight connector is a male/compression and the elbow is a female/compression. will have another look next time I go to the boat, but the straight bit is behind the splash sheet so not easy to see!

 

[nigelmercier]

...but the straight bit is behind the splash sheet so not easy to see!

Or indeed unscrew

If often find I can get a camera into places I can't easily see, and a photo would be incredibly handy.

If all else fails, I've heard back from the eBay seller who has a similar item http://r.ebay.com/qTnFIM saying that although he doesn't know if it is gas approved, the manufacturer's info says it's OK with Propane and Butane. I guess I could brush on some lacquer to prevent corrosion.

 

[KellysEye]

>standard olives

Be careful with olives tighten too much and they will leak, tighten too little and they will leak. Learnt that the hard way when replacing the boat's water pipes. Leaking gas is a whole different ball game.

 

[nigelmercier]

>standard olives ...

Don't know who you are quoting, but I plan to use copper olives.

In the past it have successfully used 15mm compression fitting from Conex as male fittings, they have a BSP thread. If manufacturers (such as Wade) published their compression thread data it would make life much easier.

 

[Nicholas123]

Suggest you look at the prices of bronze fittings compared with brass before making such statements! Examples 3/4" skin fitting brass £8, bronze £13 ; 3/4" ball valve brass £5, bronze £17, DZR £11.

That is not the case with mild steel and brass for gas fittings as they are very similar in price so cannot understand why you would use steel. And I did not say steel was not suitable for interior, although would you really want that load of rust when you can have a fitting that does not corrode?

I suggest you gen up on some of the disasters that using brass skin fittings can produce if you think that difference is significant.I can't imagine anyone that really knows anything about metal properties making a big issue out of that.
I did'nt say mild steel was preferable to brass in all circumstances you are letting your imagination run away with you there,that is just nonsense.

 

[VicS]

I suggest you gen up on some of the disasters that using brass skin fittings can produce if you think that difference is significant.I can't imagine anyone that really knows anything about metal properties making a big issue out of that.
I did'nt say mild steel was preferable to brass in all circumstances you are letting your imagination run away with you there,that is just nonsense.

Please enlighten us, especially the downsides of using brass fittings on gas systems.

 

[Bobobolinsky]

If it is just going through a water tight bulkhead, get a pipe bender and,make up a small spool piece to replace, a small length of plastic conduit to protect the pipe glued in and silicone to seal the bulkhead. Relocate the joints to somewhere easy to get at.

 

[Nicholas123]

Please enlighten us, especially the downsides of using brass fittings on gas systems.

I was replying specifically to the op's concern about his fitting which after all is the subject of this thread!Why replace it with a brass one when it ai'nt broke!

 

[nigelmercier]

Why replace it with a brass one when it ai'nt broke!

Well, it looks broke to me, certainly the top part. No way would I refit that.