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Captain Hook.

brianhicks

Joined: 5-05-01

Topics: 4

Replies: 12

Posted: Mon 28th Nov 2011, 2:39pm
Captain Hook.

Captain Hook has a marine boiler and the two clacks are low down almost at the base of the boiler on either side of the ash area. Friends tell me this may be why I experience leaking clacks from time to time as clacks should preferably be in a cool situation and these are in a hot and "Mucky" internal situation. At its 10 year test I did use a dilute acid boiler cleanser so I have given it as good a clean in that area as I can.There is a dome on top held onto the barrel by about 12 bolts. Could I drill this dome on opposite sides and fit my clacks here? Beneath this dome in the boiler is the steam valve to the pistons with the pipe to collect the steam sticking up into the dome area. Presumably when in steam this dome will have water in it but at times it may be clear of water.Does this matter when the clacks are in operation. At the moment they are always covered by water.Is a dome a suitable position for clacks and is it an allowable and sensible modification.The dome being easily removable for the drilling to be carried out. The flat top of the dome has the two safety valves and a filler plug on it. The position would certainly be cooler and I would not wish to have them positioned direct onto the boiler after just having stripped it down for its 10 year inspection. Any thoughts and advice would be much appreciated. I have a brass cover which covers the dome but I think it would accomodate the two clacks.
 

Replies To This Post

Chris B

Joined: 1-01-70

Topics: 2

Replies: 17

Posted: Mon 28th Nov 2011, 7:21pm

Brian

The dome is not the place for the clacks. The steam is collected in the dome as this is the point furthest above the water so there is less chance of any water carry-over with the steam which can bend rods or break castings if it causes a hydraulic lock whilst on the move. I have seen other Tinks with a top feed in front of the dome, i.e. a tee connected to the boiler barrel with a clack feeing in from either side of the tee. This would mean only one additional connection to the boler shell, otherwise clacks tend to be fitted on the horizontal centreline of the barrel midway along it.

Cheers

Chris
 

brianhicks

Joined: 5-05-01

Topics: 4

Replies: 12

Posted: Tue 29th Nov 2011, 11:04am

Thank you Chris B. This advice seems very sound although the height of my dome is almost 11 inches and any conection into it would be low down near the base. However I will pusue your T in the boiler suggestion. Presumably boring a hole into a boiler already tested and certified by Sun Alliance would be allowed? I seem to remember advice on this subject of additional holes into boilers in another section of this forum. Once again many thanks.
 

Peter Beevers

Joined: 9-10-01

Topics: 3

Replies: 134

Posted: Tue 29th Nov 2011, 12:17pm

Brian,
Wherever you put the water inlet in the dome, it will generally splash about and may contaminate the output steam supply, which you need to avoid.
Having a top feed is a much better idea.
The boiler cannot simply be drilled. You need to fit a bush as well, which will need to be welded on by someone competant to do it. Speak to your boiler inspector about your proposed modification to see what he feels about it. In theory, you are not altering the structure of it so should not have to do a hydraulic test again, but that is up to your boiler inspector.
Regards
Peter
 

brianhicks

Joined: 5-05-01

Topics: 4

Replies: 12

Posted: Tue 29th Nov 2011, 3:30pm

Thanks for that Peter. It would appear that I will have to talk to the builder of the boiler and having to fit a bush means a bigger strip down than I had contemplated. I might have to leave the clacks where they are and fit non-return valves into the line to counteract the leakage of steam back to the injectors.Hey Ho! Thanks to everyone. Brian.
 

paulash

Joined: 1-01-99

Topics: 0

Replies: 3

Posted: Thu 23rd Feb 2012, 9:33pm

Brian,

A bit late but I have just picked up on this topic. I have a Tinkerbell and have 2 clacks for each injector, one into the boiler and one in line. The loco is 6 years old and I have only ever had one time when the clacks have blown back so 99.9% reliability. This would be easier than adding a top feed.

Paul

 

colinedmondson

Joined: 9-08-09

Topics: 3

Replies: 82

Posted: Thu 23rd Feb 2012, 10:36pm

Most GWR and a good many LMS locos had a top feed, the water dropped on to a perforated tray which picked up a lot of the deposits and could be removed through the bushing for cleaning.
 

johnedmonds

Joined: 1-01-98

Topics: 1

Replies: 6

Posted: Fri 24th Feb 2012, 5:54pm

Brian,
I have a large modified Thomas II with a T on the boiler top with two clacks and initially had endless problems with steam blowing back. I then fitted in-line clacks (originally sold for traction engines) to the feed lines in a vertical position either side of the boiler and since then no problem. Only problem in your case might be fitting them vertically? Good luck

John
 

brianhicks

Joined: 5-05-01

Topics: 4

Replies: 12

Posted: Sat 25th Feb 2012, 11:05am

THANKS Paul, Colin and John,for your kind interest and replies. All information is of use .I will persue having a set of in-line clacks fitted but John's worrry about fitting them vertically may cause me problems as the fitted clacks are already low down near the base of the boiler.With this in mind how close is it adiseable to have them next to the ones into the boiler. Can they be as close as I could get them?
 

johnedmonds

Joined: 1-01-98

Topics: 1

Replies: 6

Posted: Sat 25th Feb 2012, 6:09pm

Brian, as far as I am aware you can fit them as close as you want. You might find some that don.t need to be vertical. Mine need to be vertical in order for the ball to seat without problem.

John
 
 
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