Steam collection pipe

[Deleted]

The steam collection pipe on my Britannia is a straight copper tube that runs back from the fitting in the front tubeplate and terminates under the dome, supported by a bracket under the dome cover - ie the open end faces backwards. I'd expected a right-angled bend on the end, to collect steam from the highest point immediately under the dome cover. Can anyone tell me what the Spink/Perrier drawings specify here?

Regards,

John

[waggy]

Hello John,

I wouldn't worry what the drawings show, go for the elbow while it's still a fairly simple job. An open ended horizontal pipe is just begging for water influx when the loco starts / stops and the water wells up. Always best to collect steam from the highest point you can.

Waggy.

[mott]

JJ, From memory and without access to the Spinks drawings now, the steam collection pipe was perforated with many small holes for steam collection. My boiler did not have a dome and was designed to draw steam through the pipe fastened as close as possible to the top of the boiler. The pipe was supported by a fastening between the safety valves.Hope this helps.Mott

[Deleted]

Hi Mott,

Mike A has confirmed your recollection of the Spink drawings, so maybe the Modelworks design is not so bad after all.

Waggy, I agree - since there seems to be space under the (low) dome cover for an elbow on the end of the pipe, I'll try to fit one, although I'll probably have to solder it on with the pipe in situ. Alternatively I could block the end of the pipe and drill some small holes along the top.

Regards, John

[paultomlinson]

Hi John
Perrier drawing shows 45 holes 1/16" dia in a 15by3 matrix at 1/4" pitch.

Regards
Paul.

[Deleted]

Hi Paul,

Thanks. What's the rationale for so many small holes - I guess it reduces the amount of water going through if there's a splash over the pipe, while still letting enough steam through?

Regards,

John

[standardsteam]

I would guess it's to reduce the pressure drop at the pipe end and spread it over a larger area reducing the risks of water lifting.

[Shawki Shlemon]

H jj
instead of soldering the the vertical pipe in situ ,screw the pipe in the collection pipe ,it does not have to be 100% sealed .Just a thought .

[gargamel140]

in the winson version you needed to bend the pipe a bit up when mounted correctly. The pipe was annealed and bended very well. Look out, not too much because it is not possible to get it out via the hole in the front. you could test it with a piece of small test pipe.

Michel