Soft solder caulking of an old boiler - New code regulations

[dem132]

Evening all, I've got question about caulking on an old existing boiler. I don't want to say the exact details about this boiler I've seen, I just wanted to see the view of a knowledge boiler inspectors would be.
I've been to have a look at a steam engine which is for sale, it's built to old design. It has a current boiler ticket from a MES, but the ticket states the following, non-known year of manufacture, or maker, but it says "copper - riveted flanges stayed + caulked". The boiler working pressure has been "lowered" to 80 PSI. No history of the boiler another than the new ticket, the first ticket / 2x working pressure was done 4 years ago.
Just wondered what general view of this boiler would be? Ok, it's got a valid ticket now, concerned that a new boiler inspector may fail it due the old design and caulking methods. I've just have a read of the new boiler code, and doesn't really this.
Please don't ask me who selling this, or the who provided the ticket etc.
What's the general view of this?

[mutley]

I personally don't see any issue with it. Plenty of riveted and caulked boilers in use. The working pressure has been lowered so the operating temp is below the melting point of the solder.

[ejparrott]

I'm contemplating

[Shawki Shlemon]

I don't know about UK but here in OZ as new codes are issued many changes and restrictions has been added to the codes but these changes are NOT retrospective and therefore boilers build many years ago which complied with with the rules of the day can still be tested and certified .

[dem132]

mutley: I completely agree, I know of few myself. But these are all in service, and that been for a good few years. My dilemma is, as the boiler doesn't have any known history, or working known history, what's the chances of a new boiler inspector looking at this when the current ticket expires and successfully passing it.
ejparrott: I'm contemplating too, as the cost of the replacement boiler is in the back of my mind. Also trying to predict whether the boiler inspectors, and insurers, and their views on such a matter. The new boiler codes doesn't really state, just says, proper manufacturing processes of the time(ok, I'm paraphrase), that's all well and good for say the 1920/ 1930's design boilers. If I build a boiler like that now, I wouldn't get a ticket for it. This is issue up and down the land, with plenty of this type of boiler in operation. My concern is that this boiler has just been a ticket.

[ejparrott]

I've slept on it, I can't see an issue. It appears to have had a 2xWP test 4 years ago? This should have been to 160PSI and fully blanked. It should have had another 1.5xWP fully fitted, and a steam test, and therefore is in ticket.

Personally though, depending on the loco, the price, the general condition, I'd be looking at a new boiler. That's just a personal thing though and is not my recommendation. The boiler on my 2.5" is 1930's vintage but is all soldered not riveted. I have no particular concerns about old boilers that pass their tests.

Bear in mind also, I am not in the habit of buying or selling models either.

[4fbuilder]

Good afternoon,

When contemplating the purchase of a locomotive the boiler question should be foremost in everybody's mind, a considerable cost if one has to replace a boiler should the original fail, not to mention the work involved in the replacement; if you have the slightest doubt to the construction of the boiler then keep a firm grip on your wallet, walk away even if the locomotive does appeal.
Soft Soldered and riveted boilers if constructed correctly will last in normal use almost indefinably provided all the normal precautions are followed including most importantly ensuring the water level is always correctly maintained. Our club locomotive is a Greenly designed Halton tank dating from the early 50s and has been in regular club use ever since, the boiler being soft soldered and close riveted and has to my knowledge never given an ounce of trouble.

Regards,

Bob

[jackrae]

Dem, something you might want to consider

When the boiler was originally built, it would be to either an "approved" existing design or to an "original" design to the satisfaction of the boiler inspection process.

Normally, a riveted pressure vessel is designed such that the strength of the joints created by the rivets alone (size, spacing, number) is adequate for the intended purpose. At one time rivets was the sole method of fabrication of stressed structures, some of which are still fully serviceable after well over 100 years of constant use.

A properly riveted joint will be both water and steam proof. However to ensure such tightness, caulking solder will often have been added to all joint edges to close off possible leak paths. The solder adds no strength to the actual design and is ignored in strength calculations.

It could be argued that a well riveted boiler is structurally "safer" than a poorly silver soldered one, since, by the limitations of visual inspection, there can be no guarantee that there are no weakening voids within the silver-soldered joints.