Hydraulic test of a Loco Boiler without stripping it down...?

[BejoDesteamon]

Hello!
I have a 3.5" gauge O.S. Krauss that I would like to bring back to working order this spring/summer.
I have stored the engine as best I can and the boiler has been blown out on its last steam up, which was about ten years ago now.
I intend to run the locomotive solely in my garden and I just want to make sure the boiler is safe, so I can have peace of mind.
Can I perform a hydraulic test without lifting the boiler from the frames, without removing the boiler jacket and without removing all the fittings and valves? Can I also use the locomotive's "built in" hand pump & check valve to supply water? I have a plug to seal off the safety valve bushing and I am aware that I must have all valves shut on the test. The Krauss's pressure gauge goes up to 11bar, which should be enough to reach twice the working pressure of this boiler (ca.10bar). How long would I leave the boiler at twice the working pressure to see if it holds up?
Any thoughts on this? Tips & Tricks?
Looking forward to your responses.
Bejo

[internal_fire]

The first thing is that you must comply with any related rules in your country or other government agency.

There is no need to remove anything that can withstand the pressure, and there is certainly no need to remove the boiler from the frame. Indeed, the closer to an actual working configuration the better.

Just be aware that you will be testing everything that is pressurized.

Why did the boiler "blow out"? Has that been repaired?

Gene

[Michael S.]

I would also get a second pressure gauge. Ideally, one with a measuring range of 0 to 20 bar. This will place your test pressure in the second third of the scale. And it should be at least Class 1. This gauge could be connected to the boiler using the sealing screw. This way, you can also check the existing pressure gauge at the same time.

Michael

[BejoDesteamon]

Hi Gene!

That's some good news!

By "blow out" I meant "blow down".
After running and having the boiler still hot, opening a valve at the base of the boiler to blow all the water and possible scale build up out of the boiler with the remaining steam pressure, then leaving it to dry before storing.

I'll have to check with my local model engineering club. As far as I remember they don't do regular hydraulic tests or steam tests, I just can't remember why.

Thanks again for the reply!

[BejoDesteamon]

Thank you Michael,
A second pressure gauge is a good idea, as you say also for checking the locomotive's pressure gauge accuracy. Why a Class 1 pressure gauge? For the most accurate reading?
I will look into that...
Thank you!

[Zephyrin]

personaly, I would remove the water gauge glass, as test pressure, much higher than "normal",  may warp the backplate and break the glass !

[Jo]

I would recommend that you get it independently inspected so ask the person who will be issuing the boiler certificate what they think. Anything else we say is just speculation.

Boiler failure can kill, or as I once saw failure of the fittings can cause extremely serious life changing burns   .

Jo

[Michael S.]

Hello Bejo,

I don't know if pressure gauges in Switzerland are also classified by accuracy class, as they are in Germany. For testing purposes, it's best to use pressure gauges with a class of 0.6 (precision pressure gauges). The 0.6 indicates the percentage deviation from the end of the scale. Pressure gauges are always most accurate in the range between 60 and 75% of the scale.

Michael

[Charles Lamont]

After standing unused for 10 years, I think all the fittings should be removed, stripped down, cleaned, examined, and refurbished where necessary.