oldnorton
Statesman
5" gauge LMS enthusiast
Posts: 695
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Post by oldnorton on Jan 10, 2024 10:24:18 GMT
Four jets of 0.55mm bore are suitable for a small 5 inch gauge 0-6-0, and four at 0.70mm for a larger 5inch 4-6-0
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Post by runner42 on Jan 11, 2024 6:23:57 GMT
I have increased the size of the blast nozzle blower to 0.028". At the other end i.e. the blower valve and tube I have pressurised to WP and opened the valve to see what effect this has of the blast of air coming from the 3 X drill no 57 holes. The results show an air blast which I would classify as moderate and not severe. Bearing in mind that the operation of the blower valve should be intitiated at 30 PSI, so at this pressure the air blast is at this pressure is less than moderate. blower valve_exposure by Brian Leach, on Flickr Here is the blower valve (poor quality photo) and the other end where the pressure was applied. blower valve1_exposure by Brian Leach, on Flickr. The drawing of the blower valve shows the internal construction and the internal pathway for air or steam shown in red. blower valve by Brian Leach, on Flickr The hole size for the valve seating is 1/16", so effectively the ultirmate pathway is only is 1/16" (0.0625") and not 3 x drill no 57 holes (3 X 0.043") Comments please. Brian
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Neale
Part of the e-furniture
5" Black 5 just started
Posts: 279
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Post by Neale on Jan 11, 2024 8:02:00 GMT
The drawing suggests that you could use separate nozzles instead. Would this be a way to try out different hole sizes? Asks a Black 5 builder who is a good year or two from this stage...
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oldnorton
Statesman
5" gauge LMS enthusiast
Posts: 695
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Post by oldnorton on Jan 11, 2024 10:04:06 GMT
Separate nozzles always a good idea. Whether fixed or not they should be angled to send the airflow to a common point at the throat of the petticoat tube. Drilled vertically, the flow will miss.
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Post by dhamblin on Jan 14, 2024 20:14:11 GMT
You don't want the blower to be too powerful otherwise it will suck more than heat through from the fire. The draughting design i.e. the petticoat pipe shape, will make maximum use of the steam jets available.
Regards,
Dan
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Post by runner42 on Feb 3, 2024 7:56:15 GMT
After putting everything back, I was faced with a new problem. The steam dome cover plate had a leak that I could not seal, no matter what methods of sealing was employed. The problem was due to the fact that the Australian boiler code required 5mm fixings and the land area using DY's measurements put the holes close to outside and insdes of the steam dome bolting face. I had to increase the land area to get a good seal. The initial sealing was OK for the 2xWP test. So I modified the steam dome cover by including an annulus affixed to the cover that extended into the steam dome. It worked.
Brian
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