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boiler
Nov 23, 2011 17:11:04 GMT -5
Post by daveb1 on Nov 23, 2011 17:11:04 GMT -5
Hi all, I have finally reached the last stage of building the boiler for my new shay. to say the least, this has been a struggle. I have patched leaks (many) and it holds water, not under pressure. My question is will I find many more leaks when I do a hydro test? I still have to install the front tube sheet which is the last step before the Hydro test. The boiler ain't pretty like some I have seen, but it does hold water. I don't know how much more patching can be done before it turns into a complete disaster.
Dave
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boiler
Jan 13, 2012 13:23:42 GMT -5
Post by phutcheson on Jan 13, 2012 13:23:42 GMT -5
Dave ..
Just wondering how the boiler came out.
My guess is that you may have a few leaks but nothing too serious that can't be fixed.
So what did happen?
Any pictures?
[/color] Pat H.
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boiler
Jan 17, 2012 10:06:40 GMT -5
Post by daveb1 on Jan 17, 2012 10:06:40 GMT -5
Hi Pat, would have responed earlier but I just got back from Cabin Fever. Great show. Anyway after the post above I tried one last water test before taking the final step of installing the front tube sheet. It turned out that I still have very slow leaks in a couple staybolts. The leaks are so slow that it is difficult to tell where they are comming from. they seep and it takes a few hours before you can see. The leaks are on the exterior. The firebox is sealed up tight. A have not been working in the shop over the holidays trying to decide whether I should start a new boiler or try to salvage this one. I am concerned that all the heating and resoldering could have weakened the boiler and as mentioned before "it ain't very pretty". I don't have any pictures but I'll take some today and try posting.
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boiler
Mar 5, 2012 14:00:48 GMT -5
Post by daveb1 on Mar 5, 2012 14:00:48 GMT -5
Hi all, after many attemps to seal the boiler up, its going to the scrap pile. The straw that broke the camels back was when trying to seal up a staybolt the mudring began leaking. I have been chasing these leaks around enough and its time to move on and apply what has been learned to the new boiler. Two mistakes I made directly affected my results. First I did not bevel the underside of the head of the staybolts. Kozo called for that but I just missed it. This was the main cause of not being able to seal up the staybolts. The original solder did not flow into the joint, but once it was down you could not get the solder into the joint. The second problem was I did not use enough solder. Kozo uses a small pieces of solder around each join. In pictures I have seen much more solder is used. This would have helped.
Below are a couple of pictures of the old boiler. I have started the new one and have completed all the bronze machining and am now forming the sheets and panels. The only thing I salvaged from the old boiler was the front tube sheet.
sorry can't figure out how to attach pictures
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boiler
Apr 29, 2012 10:20:24 GMT -5
Post by daveb1 on Apr 29, 2012 10:20:24 GMT -5
Hi all This is an update to where my progress has gone. I have started the new boiler from scratch. The only thing I'm using from the old boiler is the front tubesheet which i never installed. The outside boiler of the boiler should be done in the next few days. Its amazing compared to what happened on the initial boiler. I have used more solder on the first heating and it has made a significant difference. The fillets are better and I have probably reduced the number of heatings by 50%. It is a much better feeling. Untitled by dab112000, on Flickr Below is a picture of the original boiler and the staybolts that caused most of my problems(hope the pictures come out) Untitled by dab112000, on Flickr
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boiler
Jun 25, 2012 15:48:01 GMT -5
Post by daveb1 on Jun 25, 2012 15:48:01 GMT -5
Hi all, finally finished(I hope) second boiler. It came out a lot better than the first. It holds water but I have not pressure tested. That will be done tomorrow. Below are a couple of pictures of the old and new. Looking back, two problems that I mentioned before were not using enough solder and not beveling the underside of the staybolts and nuts. Will keep my fingers crossed on pressure testing. Untitled by dab112000, on Flickr Untitled by dab112000, on Flickr Dave
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boiler
Jun 25, 2012 17:01:07 GMT -5
Post by Ed Hume on Jun 25, 2012 17:01:07 GMT -5
It is more the rule than the exception to find some leaks when pressure testing. So, do not be discouraged, it is a normal part of the process.
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boiler
Jun 26, 2012 8:19:01 GMT -5
Post by daveb1 on Jun 26, 2012 8:19:01 GMT -5
Hi Ed, you were right. Last night I filled with water and applied 25 lbs of air. the seam in back of the steam dome has three pin holes in it. I will redo the seam today. I have to get a pressure gauge today so I can do the hydro test.
Dave
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edc
Gandy Dancer
Posts: 1
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boiler
Jun 29, 2012 9:57:21 GMT -5
Post by edc on Jun 29, 2012 9:57:21 GMT -5
Dave, How is the boiler progressing? Did it pass the hydro test? -Ed C
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boiler
Jun 30, 2012 16:33:30 GMT -5
Post by daveb1 on Jun 30, 2012 16:33:30 GMT -5
Hi Ed' Just came upstairs after some soldering. All previous leaks were sealed, but found a leak in the mudring at 25 lbs pressure. Will work tonite to fix and hook up pressure gauge and pump.
Dave
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boiler
Jul 7, 2012 13:55:24 GMT -5
Post by daveb1 on Jul 7, 2012 13:55:24 GMT -5
Hi all,
Well' Ed Hume hit it on the head when he said leaks were the rule rather than the exception. As it turned out I had several staybolts leaking using 25# of pressure. finally got all leaks fixed at 25# and went on to hydro testing. this morning got everything hooked up and went to 100#(operating pressure). Surprise, suprise. Kozo's hand pump worked floorlessly and there were no leaks that I could detect. Icouldn't hold the pressure because of the leaks in the covers used over the thru boiler fittings. I have to tighten up and do some more testing . Things are looking up.
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boiler
Jul 9, 2012 6:27:09 GMT -5
Post by kvom on Jul 9, 2012 6:27:09 GMT -5
Once the boiler is fired any seeps will likely close up as the metal expands.
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boiler
Jul 9, 2012 11:58:24 GMT -5
Post by daveb1 on Jul 9, 2012 11:58:24 GMT -5
Thanks Kvom, thats good info to know. I have learned a lot reading your A-3 thread. Keep it comming. This morning ran the pressure test up to 150# and found two small seeps, one a staybolt in the firebox and one a small bolt(1-80) on the outside of the firebox, originally used to hold Mudring in place. I'm going to fix those and then move on. Kozo says to test to 280#, but I have heard that some only test to 150% to 200% of working pressure and you should not use these pressures unnecessarily because it can stretch and weaken the boiler. I'll wait on that decision until I get more info.
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boiler
Jul 10, 2012 13:49:02 GMT -5
Post by Ed Hume on Jul 10, 2012 13:49:02 GMT -5
Kozo is specifying conservative testing values that are scientifically based on the ASME boiler code and the loss of copper strength with higher usage temperature which is much greater than with steel. But you are correct that the repeated testing at the maximum test pressure can cause noticeable swelling of the boiler walls between the staybolts. His recommendations are more conservative than has been common hobby practice. The test at 2X working pressure rule is better suited for steel which holds its strength more than copper as it is heated.
My suggestion is to not test at 280 psi until you have fixed any leaking that occurs at 100 psi. Then you can step it up - test at 180 or so and make sure there are no leaks. Only try 280 when there are no leaks at lower values.
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boiler
Jul 24, 2012 19:52:49 GMT -5
Post by daveb1 on Jul 24, 2012 19:52:49 GMT -5
Hi all, I thought I had this thing done. Two simple leaks in the fire box lead to about 4 soldering sessions. Fix one and another popped up. Anyway today I hydroed to 175#. No obivious leaks in the boiler. after 45minutes pressure went down to 40#. Some seeps were at the covers to the thru boiler fittings and a couple of seeps, one on the mud ring and the other on a staybolt inside. These were only damp after 45 minutes so I think its done. So after almost a year I'm off to start the smoke box. It has been quite an experience. As Kozo says in the book, "A successful hydro test shows....that more than 90% of of difficulty has been overcome." I'm hopin he is right.
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