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Post by terry1956 on Sept 26, 2014 8:25:46 GMT
Hi chaps. how do you make inline clack valves. I have seen these valves being used next to the injector. and have been told that in this position the valve works very well. so have do you make an inline clack valve. thanks. michael
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Post by Deleted on Sept 26, 2014 10:33:13 GMT
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Post by Deleted on Sept 26, 2014 16:50:03 GMT
Hi Michael, This is the drawing for the Pansy check valve that screws straight onto the injector:  Not shown on the drawing is that the ball is 3/16" Dia. and the seat reamed 5/32". Obviously, the boss needs to be threaded to suit the end of the injector. Another one for a 2½" gauge loco but with the outlet vertical rather than horizontal. For 5" gauge you would need to increase the sizes to take a 3/16" ball and larger pipe fittings as above.  John |
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Post by terry1956 on Sept 26, 2014 18:55:36 GMT
thanks Baggo, just what I was looking for as its going on a pansy loco and also on a MoK. will get to making once I buy the reamers.michael
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Post by Roger on Sept 26, 2014 19:12:27 GMT
thanks Baggo, just what I was looking for as its going on a pansy loco and also on a MoK. will get to making once I buy the reamers.michael You could always bore the hole if you don't want to spend out on a reamer. |
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Post by Deleted on Sept 26, 2014 20:07:13 GMT
------------why do they need to be that accurate anyway ??
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Post by Roger on Sept 26, 2014 20:17:34 GMT
My guess is that you want to have the hole in the seat pretty round so that the ball sits evenly all round. I know you use a punch to seat the ball but it's going to be a more even land that you create by that process than if you drill it.
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pault
Elder Statesman
Posts: 1,502
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Post by pault on Sept 26, 2014 21:04:24 GMT
a round ball needs to seat into a round hole,reaming is to make sure it is as round as possible, boring the hole is probably the best answer
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jma1009
Elder Statesman
Posts: 5,923
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Post by jma1009 on Sept 26, 2014 22:20:23 GMT
john's second pic is what i would regard as an inline valve but not his first pic.
laurie lawrence produced a rather tricky to make inline valve that i tried but showed no advantage over the second type shown by john.
michael, if you have a standard size injector fitted (24 oz per min) then the delivery pipe ought to be 3/16" dia thinwall OD, and the seat for the check valve 5/32" dia with a 3/16" dia ball. the checkvalve drawing shown by john is too small for a standard size injector for the tyro.
cheers,
julian
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Post by Deleted on Sept 27, 2014 1:00:25 GMT
I've never made any injectors myself but what reading about them I have done down the years always seemed to end with either the obligatory "Sharp tap" to seat the ball, and/or lap the seat using a ball soldered onto a thin stick with fine grinding paste in the same manner as a poppet valve in your car or motorcycle engine......If those two methods work (and they seem to ) then why not go direct to one or both of them and employ a drilled hole instead reaming ( ok, use a slot drill rather than a twist drill)......?? By virtue of their fitment within the pipe-line from injector ( or pump ) to boiler then any clack could be said to be "in-line"....My understanding of the terminology was that the clack to be LINEAR, ie}-- a 180 degree build....Like john's second drawing but in a straight line.................Would ROGER's use of o-rings for seating in his hand pump design work within the injector environment I wonder ??
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Post by Deleted on Sept 27, 2014 1:59:18 GMT
Both the injector clacks on Helen have O ring seats and never leak. You just need to make sure that the design of the clack traps the O ring so that it can't lift with the ball and block the clack completely. Don't ask me how I know  Julian, I did say that the second check was for a 2½" loco and would need to be increased in size for 5". It was a drawing I happened to have on the table at the time.  John |
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jma1009
Elder Statesman
Posts: 5,923
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Post by jma1009 on Sept 27, 2014 2:58:16 GMT
hi john,
i apologise, yes you did mention this re enlarging being required.
contrary to alan, i always carefully machine the clack valve seats then ream afterwards. 9 times out of 10 the ball seats ok on test (always test these things before fitting!) otherwise on the 1 out of 10 occasions i burnish the seat ala the late W.A. (Bill) Carter's method. the trick to achieve a good seat is to set the 'D' bit or end mill to a stop on the lathe so that it doesnt leave a mark when at depth and being withdrawn, and at the same time i slacken the belt. this might sound very alien to some, but trust me!
cheers,
julian
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Post by terry1956 on Sept 27, 2014 8:44:16 GMT
Well chaps, I plan to make a start on these valves next week.at the moment I am trying to teach myself how to make name plates using a UV light box and various acids. Michael
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Post by Deleted on Sept 27, 2014 9:02:37 GMT
sounds very transcendental and hippy ( "Acid" and groovy lighting ??).....
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Post by terry1956 on Sept 27, 2014 21:42:13 GMT
That's me all over Hagley. Just don't have the hair to go with it any more. michael
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