screw down regulators

[Ian RParticipant @ianr]

I have a screw down regulator that will not close off. I am in the process of removing it from the loco to try and ascertain what might be causing the problem.

 

Can I please ask what is the most likely cause of the problem. Where should I look at first the setting of the cone

Any help with this would be appreciated

[ZanParticipant @zan]

The regulator on my waggon is screw down it has a coarse pitch and rarely  needs more than half a turn for max speed or pulling passengers.  It is activated in a threaded guide with a gland nut on the body with the usual seal to allow self alignment .

The live steam is on the top of the cone which tends to push it down onto the seat .   it never leaks ( I think)! The thread was cut loose to ensure the cone could have a trace of movement to get rid of any possible misalignment
so,

1 is the hole clean on the arris?

2 is there enough slack in the thread

3 is the thread for the screw true to the body of the regulator

4 obviously the cone needs a good finish

hope that helps, some investigation needed, but it all depending on the exact   layout in your arrangement   My total screw, gland and handle  is only about 1.5” high. it’s difficult to help without more detail

[ZanParticipant @zan]

Me again!  Forgot you were referring to to a loco, my Simplex has a screw regulator, no problems with that , but again it has a slack thread .

 

Trouble is with it all being deep inside the boiler it’s a big job to get the reg body out, so you’re probably correct in starting by truing up the cone.

Don’t forget as with all valves, leave them open after steaming to stop them locking in place

[Ian RParticipant @ianr]

Sorry to ask

I am not sure what you are suggesting

1 is the hole clean on the arris?

 

[ZanParticipant @zan]

The hole in the regulator body. Is the edge clean , free from damage  and as in #3 correctly aligned with the thread, but as I said, a big job to get to it!

[Ian RParticipant @ianr]

Thank you for your input on the issue I have with my screw down regulator.

I have at last been able to remove it from the loco and check that the cone and seat look ok. I have now tested it on air.

Should I expect the cone and seat to provide an air tight seal or do these types of regulators not close completely?

Should I be concerned it not closing completely.

 

 

 

[noel shelleyParticipant @noelshelley55608]

A leaking regulator would be of concern to me. I would want to know why it was leaking and expect to get it air tight. Zen has detailed many of the causes. Noel.

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