Marine boiler build

[johnnyo]

Hi All
This is a marine boiler in 4" O.D. Type K copper tube I'm currently working on. I'm fabricating a sight glass with blow down capability and thinking about where to plumb the rest of it. Should a bottom drain be installed and ported overboard? I have two bushes on front and might use one for bottom tap of glass and other for common line for feed pumps. This is a dry back so I might pipe steam out from under dome thru back tube sheet into dry back area. No hole for it yet but aux. steam and psi gauge are in dome now. Will add hole in front of dome for top tap of glass later.I don't know if I needed type K in construction, rather heavy, but in reading various it can't hurt.
Thanks
Johnny O

 

[lennardhme]

Nice looking boiler - tell us some more about it. Your own design ?, kit ?
Leonard

 

[GWRdriver]

Very nice work, clean and built like a tank, but considering its color I do have to ask about the dome. Is that formed of brass, or bronze?

 

[Beachside_Hank]

That is a nice looking boiler. If you're going to install a bottom or surface blow valve and discharge below the waterline, you'll want a two- valve system: the main and a guard (backup) valve. On all Naval boilers the guard valve would ensure you could shut down the line in case of a jammed valve seat in the main. A check valve may be optional, but our method was to open the guard valve first, then the main, shut the guard and lastly the main so there was no boiler pressure left between the two.

 

[Jasonb]

I don't know if I needed type K in construction, rather heavy, but in reading various it can't hurt.

I would have hoped that you had done calculations to see if the materials and construction were suitable before starting to cut metal.

Your busheds also look quite bright but it may be the photos hopefully they are not brass.

Workmanship loks good though.

J

 

[johnnyo]

I did do a good bit of reading on these in books and internet, like K.N. harris model boilers, which sad to say has pages falling out from use. I also avoid brass and stick to bronze. either bearing or phos. bronze. These were used for dome and bushes. I bought pious. bronze from mcmaster for the stays and used threaded collars on ends for support. I formed the steam dome and base from bronze but would like to have used copper, flanged over if I could. I'll grab a pic of dome next time I'm out there. I used as much info from Harris book and pictures as I could in coming up with a design. DraftSight helped out a lot too in laying out tubes.
Thanks

Johnny O

 

[johnnyo]

Hi All
I got a picture of the dome and sight glass. I need to tie in bottom of sight glass to water side of boiler but don't want to use the tube sheet bushing. I want to have a hand pump on one and engine driven pump on other. I think a bushing in body on side of boiler if I can make it work. The only brass used in const, is the smoke box and tube besides this sight glass.
I'm open to suggestions on firing this as I haven't got that far. I plan on installing galloway tubes as well, so some type of torch style burner is in order. The dry back cover is filled with refract. cement 7/16" thick. By the time I add a steam engine and auxillaries this thing will be heavy.
I'm going to need a bigger boat.

 

[johnnyo]

Ok, I forgot the picture. here it is. Forced myself thru making those 3-48 model nuts, like machining popcorn, but you can't eat it.

 

[GWRdriver]

For future reference, . . . many builders include rivets for their aesthetic/visual effect, but as for strength, a sound silver solder joint is stronger than the parent metal so you only need to use enough rivets (or screws, pins, etc) to hold the components in place during silver soldering to achieve maximum strength. Otherwise, you've done your homework, a very nice looking job so far.

 

[johnnyo]

Well Harry, I simply riveted, hope I can seal all those bad boys come solder time.:fan:

 

[GWRdriver]

If you solder as well as you build, and have enough heat (and flux), it should be a piece o' cake.

 

[johnnyo]

I finally got around to model work and this is some of my accomplishments. I worked out a sight glass and plumbing for it, after changing course in mid stream on it a couple times. I wanted a valve line up to allow blow down and found some nice 1/4" valves and unions at A&K locomotive. The sight glass is made up of 3/32" braze rod with 3-48 nuts and o-rings fitted in block ends.I made up a burner tube with a spiral array of galloway tubes, 6 each, thought it might have less flow ressistance given the two pass flue design. I used the white harris flux and stat-silv 56 this time with better results. I did a leak check with blanked off ends and 100 psi air. I had a couple visual indications but a leak turned up where none were visible. I fitted a banjo style buying port into the back tube sheet for a super heater and ran that into a cartridge style stop valve in dry back area. Sorry if this is a little long winded.
Johnny O

 

[gus]

Hi Johnnyo,
Very fine and superb workmanship and finishing.Please advise design and working pressure? Shell plate thickness and shell plate thickness and material specs. We could run a calculation to ensure thickness is adequate with the material used.
The AMDSC CODE Part I would be useful as reference material.

Hi Cogsy,please chip in.


Gus.

 

[johnnyo]

Hi Gus
I love fishing myself, what are you holding there? I surf fish new jersey and the outer banks but this jan. I'm heading to fort lauderdale with the wife for my 50th b-day. Will try to get some surf fishing in too. Anyway, All the copper tube used in the boiler is type K plumbing grade, not sure of exact make up. I prefer to over engineer like nasa so I'm failsafe. The shell O.D. is 4.125 and the tube sheets are formed from a flattened sheet of same tube at .125 thick. The burner tube is 1.625 O.D. and flue tubes are 3/8". I put 4 phos.bronze stays in with 1/4-40 collars threaded on ends. I also plan on flaring both ends of the 3/8 tubes. The working pressure is below 75 psi as that is the approx. set point of the safety. I'm thinking 40 - 60 psi? I haven't figured out my burner yet, leaning towards gas fired ceramic style like the Macsteam burners. I built the pmr vertical boiler and mounted a propane burner in the firebox to get up enough steam for the Cygnet royal 3 cyl. rad. engine it ran. Much better then the tablets they sell. Great kit build too.
Thanks
Johnny O

 

[gus]

Hi Gus
I love fishing myself, what are you holding there? I surf fish new jersey and the outer banks but this jan. I'm heading to fort lauderdale with the wife for my 50th b-day. Will try to get some surf fishing in too. Anyway, All the copper tube used in the boiler is type K plumbing grade, not sure of exact make up. I prefer to over engineer like nasa so I'm failsafe. The shell O.D. is 4.125 and the tube sheets are formed from a flattened sheet of same tube at .125 thick. The burner tube is 1.625 O.D. and flue tubes are 3/8". I put 4 phos.bronze stays in with 1/4-40 collars threaded on ends. I also plan on flaring both ends of the 3/8 tubes. The working pressure is below 75 psi as that is the approx. set point of the safety. I'm thinking 40 - 60 psi? I haven't figured out my burner yet, leaning towards gas fired ceramic style like the Macsteam burners. I built the pmr vertical boiler and mounted a propane burner in the firebox to get up enough steam for the Cygnet royal 3 cyl. rad. engine it ran. Much better then the tablets they sell. Great kit build too.
Thanks
Johnny O

Hi Johnny,

By chance if you happen to drop Singapore,will take you out for a spin and beer and if the fish bites. I put in Fish Attracting Device. Three months ago and some fish came. Bought an Albin 28 with 300hp engine and does a top speed of 24 knots but guzzles diesel. Cruising at 15 knots best fuel economy.

 

[johnnyo]

Got busy in shop after fire warmed it up a bit. Burner tube had one leak in test rig but passed after touch up. Used 100 psi air w/snoop. Steam dome soldered up nice, used the black Harris flux after thinning it out with water. Mounted dome with black flux and .005 the. braze ribbon. Used stay-silv 56 around rivets on inside. The cartridge valve with a Ti. valve stem and sight glass are shown waiting patiently for installation, off to the shop.

 

[johnnyo]

Hi, managed to get both tube sheets and burner tube soldered in after fixing wife's dishwasher. Membrane buttons failed in panel, I'll take a machine with hard wired switches over these anyway. A lot easier then keeping the heat up on this boiler though. Working it on top of the wood stove helped. I used the black Harris flux again and placed segments of the 56 stay-silv on the back tube sheet and melted it into joint. It should be ok to use the Easy-Flo solder on the rest now.

 

[gus]

Looking Great. Brazing Good.

 

[johnnyo]

Finally finished last piece, Used PMR's low temp solder and harris stay clean flux on flue tubes, stays, bushings and rivets. Will run Hydro test after bushings are made for blank off. Hey Gus, you might recognize this name plate from my past work experiences.

 

[gus]

I worked on XLEs. Between my Aussie Boss and me we captured all the major shipyards with XLEs. Every yard had two 500hp x 6.6kv XLE compressors. WOnderful machines they run forever.The screw compressors took over for ease of installation but they suffer from customer neglect and infrequent oil change. A new screw air end cost a fortune. However today with computerised surveillance,these machines will operated for a long time.

Thanks for posting the nameplate.Johnny.Where were you based? I designed and packaged the Indian ESVs in 1970s and took away orders from BroomWade and AtlasCopco etc. The biggest ESV package built was the 100hp ESV 12x9.