DJB Automatic drain cocks

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Whosk

DJB Automatic drain cocks

Post by Whosk » Sun Sep 14, 2014 2:03 am

Has anybody had experience at fitting these drain cocks to a Ragleth or Egrid? is it hard, is it worth it, do they work?
The initial run and clearing the condensate is quite unsatisfactory and unprototypical to my mind, besides looking like a goose trying to get it to run backwards and forwards while others/public are watching.
I have minimised the problem with technique , ie, run a bit less water at the start and letting the steam blow well before shutting the blowdown valve. They seem like they might be the next best step-providing they work!

Wayne

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AFGadd
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Post by AFGadd » Sun Sep 14, 2014 10:42 am

I've fitted these cocks to a couple of Accucraft engines and in my opinion they do work.

Fitting is, I believe best done by removing the cylinders and using a small pillar drill to cut the holes.
I found the easiest method to remove the cylinders was to remove the body & boiler as well.

However, I didn't find the job difficult or daunting but the job does take thought.

The rewards were certainly worth the effort.

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Andrew

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tom_tom_go
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Post by tom_tom_go » Sun Sep 14, 2014 5:21 pm

Thanks for posting Andrew as I was wondering whether to fit these to my Ragleth.

When you took the cylinders off did you have to set the valve timing again?

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Post by AFGadd » Sun Sep 14, 2014 9:29 pm

I did reset the timing, it is not that difficult. There's a document floating about on the net that explains how to set Accucraft gear.
It's seriously easier that RH valve setting...
Andrew

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LnBmad

Post by LnBmad » Fri Sep 19, 2014 1:58 pm

i may have to give these a go as well.

Big Jim

Post by Big Jim » Fri Sep 19, 2014 10:44 pm

This may sound like stupid question but once the condensate is cleared do they affect the way the loco runs at all?

Apologies if it really is a stupid question.

LnBmad

Post by LnBmad » Fri Sep 19, 2014 10:48 pm

I believe they work via a ball bearing that closes when steam pressure is there and open when condensate needs to escape.

LnBmad

Post by LnBmad » Fri Sep 19, 2014 10:50 pm

I'd like to see a video of them in operation if possible

steam4ian

Post by steam4ian » Sat Sep 20, 2014 12:11 am

There is a lot of discussion about these valves in the ride behind gauges as well.
As LnBmad says they consist of a ball bearing in a chamber which can at some point seal off the outlet. Operation relies on the interrelationship between the size of the entry port from the cylinder, the chamber containing the ball and the exit port. I think that if the entry port is smaller than the exit port they will work because condensate does not expand. The condensate velocity into the valve is more than that leaving the valve and the ball is not driven to the exit port. However steam will expand and its velocity will lift the ball to seal the exit port.

One problem I see with ride behind gauges is that they can't relieve priming where hydraulic lock up means a rod will get bent or worse.

LnBmad

Post by LnBmad » Sun Oct 05, 2014 9:00 am

Have fitted them to my ragleth. Totally worth having!!!

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