Water in vacuum brake pipes.

Hi folks

Does anyone have problems with water in vacuum brakes. This is frequently noted and loco staff put it down to condensation. I am concerned about the amount of water and what it will do to brake cylinders. Am I worrying too much ?

 

Namron,

Water in the vacuum system of carriages is a problem not to be ignored, as it will result in corrosion of the brake cylinders. It is unlikely to be condensation, unless you have particularly unusual local climatic conditions.

One possibility is that water has entered via an open PCV (communication chord air valve) that is not protected from the weather.

Most likely is that it is being introduced by the brake ejector of the locomotive, the designers of which go to great lengths to ensure that any condensation is drained away automatically and does not reach the flexible coupling hoses. Most locomotives have a high swan neck for the hose as part of the design to avoid this.

What design of locomotive has recently been coupled to the stock in question?

Andy.

 

Hi Andy. Thanks for the reply. It's an ex industrial Hudswell Clark loco. You can probably guess where I am .
If you know of anywhere we can get a short screw coupling for this loco I would be grateful also.
Thanks
Norman

 

As Andy has suggested, the first place to look is the loco vacuum ejector. I'll hazard a guess that it is a Penberthy type ejector and I'll make another guess that it is wrongly installed. Most such installations have the ejector placed such that the suction is pointing downwards, probably because that is how they are always illustrated. When the ejector is turned off any condensate will simply gravitate into the vacuum pipe and even find its way past the non-return valve. I always install these ejectors with the suction either horizontal or pointing vertically upwards and there is no problem with water. One loco we inherited that had the usual arrangement caused problems until the arrangement was modified, as suggested.
As has also been said, if you don't eliminate the cause, you will have problems with your vac cylinders. Experience tells me so!
Edit: You also need to put a drain at the low point of the exhaust pipe.

 

Wise words Steve.

 

An automatic drain (drip valve) in the loco train pipe is also a good idea. These are usually shown on schematic drawings but often omitted during rebuilds.

 

Thanks guys. I have water everywhere in the system, two cylinders not working properly with water draining from release valve. Stripped a DA valve this morning and found water. O joy.