Lubricating the regulator valve.

[Thomas ClarkeParticipant @thomasclarke78224]

Before I put the regulator back in the boiler I was wondering if I need to lubricate the valve which has the O rings attached with steam oil. On the Reeve’s drawing there doesn’t seem to be a mention of O rings. Is this just another way of producing the valve.

Thomas

 

 

 

[Howard LewisParticipant @howardlewis46836]

Whether the regulator is before or after the superheater shown, the O rings will benefit from lubrication.

To be on the safe side, my choice, as a non steam addict, would be a steam oil intended for  a superheated locomotive, to withstand the higher temperatures. Even wet steam at 100 psi will be well above 100C, nearer to 200C, so an ability to withstand such temperatures will be needed.

And it will need replacing from time to time, so start thinking about how the oil can be fed to it, without risk of polluting of the steam system, upstream of the regulator.

Howard

[Paul KempParticipant @paulkemp46892]

I am not familiar with that style of regulator but it looks like saturated steam enters through the large “pipe” the valve slides in and passes through the holes in the valve the valve pulling back to uncover the port to the superheaters, it’s a kind of balanced valve I assume?  In which case any oil on the O rings particularly the one closest to the boiler will migrate into the boiler and cause priming.  Priming is the devil on a superheated loco as the entrained water will flash off in the superheater elements which is downstream of the regulator so closing the regulator will not stop the engine until all the water has flashed to steam and been consumed!  Great fun on a full size where your only option is to get the valance gear to mid gear – don’t ask me how I know!

I think your only option is to fit it dry and in any case there is no provision to introduce further lubrication beyond the initial fit.  I would also suggest you do a pressure test on the super heater elements before you refit it all.  Any pin holes will allow leaking steam to destroy or reduce the smokebox vacuum and lead to poor steaming.  While it’s out it would be better to test it to be sure, some of those joints look a little suspect.

I have a loco that can barely maintain steam due to a suspected leak on a superheater…

Paul.

[Nigel Graham 2Participant @nigelgraham2]

That seems a very unusual design, but is a form of poppet-valve.

The regulator is about the least accessible unit on a locomotive, and is normally designed to operate without any lubrication other than water, and virtually no maintenance for the life of the boiler. It is handling wet steam, albeit at high temperature.

As Paul says, oiling the valve risks oil in the boiler, hence priming, but you can’t reach it to oil it anyway. (I wonder how traction-engines manage in that regard, with the cylinder and valve-chest on top of the boiler.)

So why the O-rings anyway, on the photographed physical valve? According to the part of the drawing you show, there should not be any. Or are they off-camera?

Wear will eventually allow some leakage past the valve bobbin, but I think the metal will wear far more slowly than the O-rings. If they are not specified on the drawing, which indicates none on the portion you show – don’t fit them. They could give more trouble than they are worth, and the empty grooves may give a little labrynth-effect sealing.

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