Boiler Testing

I need some help, I am in the process of building another small boiler for a traction engine and need to test this myself, if I use a hand pump and a 2" pressure gauge with a maximum callibration of 300psi how should the pipework run from the pump via the gauge to the boiler fitting should the gauge be teed off from the main pipe run

If at all possible gauge and pump should be separately connected to item under test.

If a single connection point is used, there is always the possibility that (due to a blockage) you are testing only the piping and gauge, not the boiler itself.

Ok that makes sense, is there a picture or sketch somewhere I can view

Talk with the boiler inspector who will be doing the test. If he has not seen the boiler during the build it is more than likely he will want to see a bare boiler.

You really should not have many threads in copper, bushes should be bronze so they don't get damaged.

There should be no brass directly attached to the copper boiler and, yes, a bare boiler is required for the cold examination and the initial test at twice working pressure. It is likely the pressure gauge and obviously the safety valve(s) cannot be in place. Colin

I think anything brass above the waterline is fine. Of all the things on this forum, this seems to be the issue people and busybodies tend to get irate about, life is too short, so i'd rather keep out of it.

Michael W

But of coure you could not resist the temptation

I'm afraid that as a boiler inspector won't have seen the boiler during the build they will want to give it an all-over inspection which will probably mean taking it out of the frames.

I suggest you find your local ME club, join it, and talk to their inspector. On the plus side membership fees are usually are modest and you will get access to their track and usually plenty of advice.

Neil

Do what you like in private, but if you hope to run it in public you'll need insurance, and you won't get insurance without a boiler ticket.

Quite hard to ensure private. If the meter reader or repair man was around due to a visit to do something paid they would be at work. If the grand children or a niece was around when something went wrong would they sue.

Best solution is to get it tested at a club for your own pice of mind. Your going to have to blank off all the connections other than the ones used for the times two test, but it's not onerous.

Steve

Hi John,

Duncan and Steve are absolutely correct, and having seen one pic of your 5"g Tich boiler in your album I would highly recommend you get it hydraulically tested by your club boiler inspector! He may refuse to issue a certificate if he has not seen all stages of construction, but at least a proper hydraulic test might suggest whether you want to sit so close behind or allow anyone else near and dear or not so dear so close to a potential 'bomb' (as all boilers are, potentially, of course).

Cheers,

Julian

No there aren't, This is because the builders perform a hydraulic test to twice the working pressure, and a steam test to ensure that the safety valves can cope with the maximum output the the boiler is capable of. John, you say you have no certificate, but have you at least tested it yourself? If not, please do so!

Maurice

John, it looks like you may be using a compressor to test your poiler going by teh air hose fitting. If so make sure teh boiler is brimmed with water as if something did let go it won't be as explosive as a boiler full of compressed air.

As Maurice says with the boilers being checked at intervals during construction, on completion and regularly after that luckily there have been few failures in public. Probably would not hear about one going bang in a back garden unless it was fatal.

Testing on air is really asking for trouble. Even if the boiler is full of water the interconnecting pipework and compressor reservoir are not, so there is a fair bit of stored energy. Fortunately copper is very ductile so is not likely to go off with a bang, but if a joint does start to unzip, it will go a lot further than if all water, when it would just spray a bit of water out

If you are making a hand pump for the loco use that, it will test that the pump works as well. A gauge bought from a hydraulic hose factors will do for a look see but it won't be calibrated but would allow you to check before going to your club inspector.

Steve