jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 2, 2016 0:27:39 GMT
hi adam,
that is a very valid question which i have previously pondered over. is the pipework too small?
it is 5/32" OD with 1/8" bore. i fully accept that each side tank will have to be filled one after the other. however with a 5/16" dia balance pipes the same procedure has to be employed anyway!
the well tank which is the sump for feed to the injectors has 2 x 1/8" bore tubes filling it from the side tanks.
i dont think a situation will arise when both injectors will be needed at the same time. it is a very small boiler for 5"g. the injectors are only 12 oz per min. they have already been tested. the water valves suitable for 26 oz per min needed throttling down quite a bit so i propose drilling the plugs in the injector water valves only 3/32".
there is also the additional feed from the LBSC wagon to the well tank (dummy vacuum reservoir).
both injectors are of lifting type so have a degree of suction on the water side anyway.
cheers,
julian
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Post by Cro on Mar 2, 2016 7:24:18 GMT
Be interesting to see, I know for many tank engines i see quite larger bore tube, usually plastic of sorts so 1/8" does sound pretty small in that respect. Does the rear bunker not have a tank on the terriers or is it tool boxes and coal I can't remember?
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 2, 2016 22:23:47 GMT
hi adam,
you are quite correct that the Martin Evans drawings for Boxhill show an additional tank in the lower half of the coal bunker plus the tool box on the end, a sort of well tank below.
i decided at an early stage to make a LBSCR wagon to go behind the loco for extra coal and water.
i thought it a bit of a shame to depart from fullsize to have a tank in the coal bunker and toolbox.
Simplex and Super Simplex have a similar arrngement with the coal bunker being mainly for water which i wasnt fond of.
i have also significantly strengthened the rear of the loco by adding frame stretchers in exactly the same position as fullsize, plus my rear drawbar goes to one of these stretchers just behind the firebox same as fullsize. it can be seen in the above pics. i have probably created a lot of complications as a result!
the balance pipe size is really only a problem when filling only one side tank. it doesnt have any effect on the operation of the injectors. i am using K&S copper tube which is very thinwall tube.
that is my reasoning anyway!
cheers,
julian
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Post by Cro on Mar 2, 2016 22:40:39 GMT
All planned out! The comment regarding the injectors was more as I understood you had both injector water valves fed from the same fitting on the tank and I just wondered if that could cause any conflict but like you say there is a small possibility of having both on at the same time.
Keep the updates coming
Adam
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 4, 2016 21:39:56 GMT
a bit more progress... here are the 2 injector water valves of quarter turn parallel plug type.  the bodies are 7/16" dia (i could have made them 3/8" dia but in any event they are hidden from sight between the frames underneath the rear of the cab). union connections are 1/4" x 40 tpi. the plug is turned from gunmetal and the stainless 3/32" rod silver soldered to it. the plug is 3/8" long and 6mm dia. the cap on top is 5/16" hex with a 9/32" x 32 tpi thread. i used a brand new 6mm endmill to finish the blind hole for the plug in the body. cheers, julian |
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Post by Jim on Mar 4, 2016 22:28:58 GMT
They look very neat indeed Julian. Would you mind if I borrowed the concept for Boadicea's water feed valves?
Jim
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Post by Roger on Mar 4, 2016 22:54:36 GMT
Hi Julian,
So am I right in thinking that there's no gland on the valve shaft and that the valve seals by virtue of being a very close fit in the body?
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 4, 2016 23:51:30 GMT
hi jim,
please feel free to copy.
hi roger,
the cap screwed into the top of the body through which the rod goes acts as a gland nut. the packing will be old fashioned asbestos graphite string or braid soaked in oil, and goes under the cap.
ive plenty of the old packing, whereas i dont have much PTFE plus it is expensive!
the plug is a very good fit. there is a very good reason for this because if not, scale can form around it seizing it up. this is a common problem with tapered plug cocks so i much prefer the plain parallel plug for something like this.
cheers,
julian
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Post by Jim on Mar 5, 2016 3:44:14 GMT
Thanks Julian.
I imagine that if carefully made and fitted very little if any water would leak past the plug given too that there is minimum pressure involved. The design is just what I was looking for as I much prefer to make my own fittings knowing they will do the job I want them to do in the given location.
Jim
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miken
Statesman
Posts: 502
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Post by miken on Mar 5, 2016 17:51:39 GMT
Good work Julian,
I make my injector water valves in a very similar way except that I turn the plug part about 2mm undersized and fit a ptfe sleeve over it. I pin the sleeve with a bit of 1.5 stainless wire. With the ptfe sleeves you dont need any gland packing. Ive made them in-line and 90 deg like yours
Mike
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 5, 2016 20:32:25 GMT
i am very grateful for Jim and Mike's kind comments. ive busy today doing the pipework for the injector water valves from the well tank/dummy vacuum reservoir...   i wouldnt normally bother with pipework on here, but some of the recent stuff on Stepney has been a bit fiddly and might be of interest to show what can be packed into quite a tight a space. the unusual 'T' piece off the well tank took 2 attempts to silver solder. it is just 3/4" long, and has injector type flat ended cones (otherwise it cant be removed). it needs cleaning up still. the injector water valves are positioned so that the rods come up just in front of the rear spectacle plate by the rear cab boxes. in such a position they are hopefully inconspicuous - because this isnt the prototype position. the prototype position is in my opinion extremely difficult in 5"g. anyway it's all good fun! i am quite enjoying the recent bits. cheers, julian |
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Post by Roger on Mar 5, 2016 20:43:38 GMT
i am very grateful for Jim and Mike's kind comments. ive busy today doing the pipework for the injector water valves from the well tank/dummy vacuum reservoir... i wouldnt normally bother with pipework on here, but some of the recent stuff on Stepney has been a bit fiddly and might be of interest to show what can be packed into quite a tight a space. the unusual 'T' piece off the well tank took 2 attempts to silver solder. it is just 3/4" long, and has injector type flat ended cones (otherwise it can be removed). it needs cleaning up still. the injector water valves are positioned so that the rods come up just in front of the rear spectacle plate by the rear cab boxes. in such a position they are hopefully inconspicuous - because this isnt the prototype position. the prototype position is in my opinion extremely difficult in 5"g. anyway it's all good fun! i am quite enjoying the recent bits. cheers, julian Hi Julian, Please show everything, it's really interesting and useful, especially for those of us who are about to tackle this for the first time. I'm looking forward to seeing STEPNEY up close for myself. |
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 5, 2016 22:21:47 GMT
hi roger,
i will do my best! it is quite difficult to decide what is a bog standard job and what might be of special interest on here... you have upped the stakes so to speak!
the silver soldered joints above remind me of a blazing row i had with my old club boiler inspector. he soft soldered all the pipework on the club boiler test rig and i replaced it with all with new silver soldered pipework and connections. then he soft soldered some steam pipe fitting connections on one of the club locos!
cheers,
julian
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Post by Roger on Mar 5, 2016 22:40:41 GMT
Hi Julian,
I guess you're so used to these jobs that you take it for granted that we've all seen the ways these things are done. Another good reason to show things is because it throws up other things of interest. For example, there's what looks like a valve on the brake cylinder. Is that some kind of relief valve or drain?
I'm staggered that a boiler inspector wouldn't know about the whys and wherefores of soft solder!
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 5, 2016 22:59:39 GMT
hi roger,
the valve on the steam brake cylinder is a pressure relief valve set at 10 psi. it is my variation on the standard Martin Evans fitting. It provides an automatic drain function, and is far preferable IMHO to the type used by Don Young, but far more tricky to make. it is one of the few Martin Evans design details i use. The Martin Evans Boxhill drawings dont have a steam brake cylinder, just a basic handbrake.
cheers,
julian
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Post by Jim on Mar 5, 2016 23:08:34 GMT
Photos of work and progress are handy for showing others the solutions you have come up with and even if they are 'bog standard' for you they may not be for others. For example I thought I'd 'been there and done that' till I saw your 1/4 turn water valve and suddenly the light went on and I realised that was exactly what I needed for my tender. Of course I had a, 'Now why didn't I think of that?'moment but the fact is I hadn't until I saw your photos. The other value of having a photographic history of your build is in looking back to see how you tackled a job earlier when someone asks you how you tackled a particular task. All this rambling is to say I'm with Roger, photos of builds are of great interest to the rest of us so please keep the shutters clicking Julian or we'll all be cross with you.   Jim |
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jma1009
Elder Statesman
Posts: 5,922
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Post by jma1009 on Mar 5, 2016 23:44:20 GMT
hi jim,
that is very kind of you. perhaps for the next bit of pipework i will describe the silver soldering. i cant myself see how anyone would have difficulty silver solding on cones onto the end of pipework till i failed today!
i must be getting old and lost my touch re silver soldering! i was being too mean with the silver solder plus had the connections on the union nuts badly arranged that acted too much as a heat sink.
cheers,
julian
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Post by springcrocus on Mar 6, 2016 7:39:36 GMT
Hi, Julian
I agree with Jim and Roger, please keep posting pictures and descriptions of the work you do, no matter how simple you think it is. There is always someone out there who will be learning and get that "Aha" moment. And consider also, if everyone stopped posting just because it had been done before, the forum would grind to a halt and just wither away.
Cracking work Julian, and please keep sharing it.
Steve
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Post by GWR 101 on Mar 7, 2016 9:50:04 GMT
I am just at the pipework stage and am also looking forward to any help that I can get.
Regards Paul
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
Posts: 2,269
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Post by smallbrother on Mar 7, 2016 13:05:21 GMT
Yes Julian please show as much as poss.
Soldering cones takes me several goes every time. I have no idea why it fails then eventually works as I do the same things as far as I can tell.
Pete.
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