Fowler Regulator

[Andy StopfordParticipant @andystopford50521]

Does anyone know how this regulator works? It looks like it something’s going on with the curved bit on the right hand side as the linkage pivots about the centre of the actuating shaft, but it’s not at all clear:

[JasonBModerator @jasonb]

If anything like the A7 then Fowlers used a round valve with a spigot on the end. A bridle went around this and was moved by the regulator rod. I would say you have the rod/bridle as the horizontal part that is moved by the lever from the rotating spindle. hatching direction would suggest the valve is possibly two parts.

[Andy StopfordParticipant @andystopford50521]

I think it may be intended to give a progressive opening so that the small orifice in the lower part is uncovered first, and then that disc is slid back to uncover the main opening… somehow.

It’s probably too finicky to reproduce in 1/10th scale, but it would be interesting to know how it works.

A ball valve in the left hand passage is probably a better bet, but that may mean making it from scratch – the smallest I’ve found commercially available is a bit too big.

[JasonBModerator @jasonb]

Haining did away with the levers and just had a rotary valve on the end of the rotating spindle. Just a round shaft with a flat on the side that covered or uncovered the junction of two drilled passages – one up from the boiler and the other to the HP valve. His Superheaters were dummies.

[Andy StopfordParticipant @andystopford50521]

Do you know how well that worked, Jason? It seems like it might be leaky and troublesome.

[JasonBModerator @jasonb]

No. The spindle itself looks to be sealed well enough with two O rings but you would need to do some careful lapping of the valve and it’s housing to avoid some steam making it through. It would be much the same with making a ball valve.

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