air/boiler

[David Bothwell 1Participant @davidbothwell1]

Just completed piping my Maisie through the backhead and boiler, but I am rather dissapointed at the lack of power to the wheels. I have made sure all the backhead fittings are leak proof, just wondered if this is to be expected with a small boiler (and compressed air)? Or could there be other places where air leaks could be, clacks or drain cocks?

[David Bothwell 1Participant @davidbothwell1]

low power

[Dave HalfordParticipant @davehalford22513]

Running on a compressor the boiler size is irrelevant. If the gauge on the boiler says 50 and the compressor isn't a toy one that can't keep up. After that the timing might be off.

I would check for leaks with a paint brush dipped in slightly thinned fairy liquid and see if anywhere blows bubbles.

[David Bothwell 1Participant @davidbothwell1]

Thanks Dave, The compressor is fairly substantial, The chassis ran on air with a pipe direct to the cylinders and had a lot of power, As you advised I will check other joints

[Brian Baker 2Participant @brianbaker2]

David, if it was OK as a chassis and is now not so good, dare I suggest that somewhere in the main steam circuit there is a restriction, impeding steam/air flow.

Assuming you are on top of the small leaks, first place I would suspect is the regulator not opening enough., or perhaps some jointing material, if you used it, blocking the steam pipes.

Perhaps you could check the regulator by opening up the wet header, and checking for a good air flow down the system, progressing onwards section by section to the steam chests.

Good luck.

Regards

Brian

Edited By Brian Baker 1 on 18/02/2021 16:41:57

[David Bothwell 1Participant @davidbothwell1]

T,hanks Brian I will follow your advice carefully in the morning, I do suspect the regulator, which I did not build

[Jeff DaymanParticipant @jeffdayman43397]

I suggest a test using one gauge on the boiler and one gauge at the cylinders. You may find that by feeding air to boiler at 50 psi you don't have 50 psi at the cylinders, due to losses through the regulator and pipes. I do not know what regulator design your engine has, but many regulator designs I have seen have very small openings and will not give full unrestricted flow from boiler to piping to cylinder.

The best flow you can get is using a ball valve if it fits. Second best is the screw-down type where a conical plug closes off or opens flow to the cyl pipe. If designed with a fast thread to allow it to fully open (equivalent to area of delivery pipe) it is almost as good as a ball valve.

However – full flow of steam may cause engine to spin the wheels – so fine flow adjustment when first opening the regulator can be as or more important that max flow. Just food for thought.

[David Bothwell 1Participant @davidbothwell1]

Thank s Jeff, A very interesting reply, my regulator is the screw in type with "course" thread. I will take a closer look in the morning

[David Bothwell 1Participant @davidbothwell1]

Sorry for the slight delay but I have sorted out the problem, It was a 90 per cent blockage in the final nipple tothe cylinders, my thanks to all who replied and offered assistance, which was useful.

[Jeff DaymanParticipant @jeffdayman43397]

Glad you found the problem David!

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