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Class 4 tank

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Stuart:
Here is the valve in bits for a 100 psi valve
with all the small holes and the larger ones the escape area far exceeds the calculated requirement in fact the very centre ring would be OK but its not scale

operation
the ball seats on a reamed hole and is held in a carrier this is the positioned in a counter bore, this is the critical bit and the reason why they work the gas ( steam ) lifts the ball then when the ball has lifted a few thou it the impinges on the under side of the carrier ( the fine lip ) this then helps the valve to lift further and reset without to much pressure loss.
The most important thing is the spring they are not a bit chopped off a long length as some do the end would not be square nor would the compression force be the same they are made by Lee springs and are made to a specific length and poundage from memory they are only about 7 llb. to solid

the original work on the mild pop valve in its various  form was done by Gordon Smith who did some article in EIM about this subject I have one done as an open valve for a 14xx with two valves in one body

all the parts




inside bit together

the ball carrier is counter bored to hold the ball but with a specific amount protruding
you have to make up the lower valve body just with the inlet bore ,offer the ball and carrier up and use a feeler gauge to get it correct

inside the body
the body cavity is critical for its shape the lower part is related to the ball carrier and has to be correct to 0.001 "


bits and bobs


the above is a size comparison  the big drill is 1.2 mm the tap is a 12 ba and the small drill in a no. 80 i do get down to 16ba for other parts such as window frames

Stuart

arnoldb:
Thanks for showing the disassembled valve Stuart  :) - quite a bit more detailed than the couple I've made so far!

Kind regards, Arnold

lazylathe:
Hi Stuart,

That looks great!
How long have you been working on it for?
It looks like a lot of time has been spent on this project and it looks awesome so far!

Andrew

Stuart:
Arnold

yes they have a bit more than most but the lift well and reset about 5 psi below setting not 15 or so with the simple type and they pass the accumulation test with ease


Andrew

there is about six and a half years work , but i have done 3 stirling engines and a vertical boiler and I have a triple expansion on the go now , I use these to break up the long job as it can get bogged down, inc the 6 1/2 years is the boiler , I have the tank shells beaten out they are not straight sided but follow a large rad in the horizontal plane like the boiler only much bigger rad they will take about a year to do along with the cab .


the drawing pack runs into 15 sheets of AO

the lubricator you see is a dummy the one on the other side is the working one the box is about 3/4 " by 1" and contains the pump , very simple one with two o ring separated by a spacer though which the plunger passes alter the space to alter the feed. This then feeds an atomiser ( steam fed ) .

as you said a lot of work and a lot of 1/16 od pipe work for the oil lines then fitting have to be made out of 3/32 hex with small ss on nipples , just realised I have to make up the swab boxes


Stuart

Stuart:
managed to get NTL to sort out my home page ( they had screwed up the permissions )

here are a few more pics from an earlier time










note the loco is on its back in these pics

the second one shows the ex pipes


thats a 6 inch rule on the frame for scale

Stuart

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