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Post by ejparrott on Dec 20, 2013 9:56:29 GMT
Do the Wakefield et al lubricators have check valves at the pump as well as the point of delivery?
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Post by wdiannes on Dec 20, 2013 10:38:22 GMT
For what it is worth I feel a few comments may be of use. Coming from full-size (traction) background mechanical oilers are usually tested with a gauge to ensure they can deliver well above boiler pressure. This ensures they will deliver oil under ANY circumstance. I have never seen a stop valve included in an oil line and would question this practice. If the valve were closed accidentally, there is a likelihood of blowing a fitting apart in the oil line AND getting no oil to the cylinder. Both can ruin your day!  I have seen oil lines from one-cylinder pumps T'd with the split (individual) lines run to check valves on each cylinder chest - BAD IDEA! The oil will NOT be distributed evenly. Differences in chest pressure and check valve springs will always favour one cylinder at the expense of the other. A single pump oiler should ONLY be fed to the shared line between the throttle and the T. I acquired a 1.5" scale loco last spring and found badly rusted cylinders on delivery. Of course I dismantled and cleaned the oiler and all the lines and ensured the pump was working but I STILL ended up chasing oil problems for the entire summer  I found: 1. the check valves at the valve chest were not reliable. The commercially produced model check valves were replaced with industrial check valves. Still no good. 2. the oiler was driven from the valve motion and the motion reduced as you "notched it up" and in the company notch there wasn't enough motion to activate the oiler ratchet reliably. (I didn't find that out until I put a crank on the oiler shaft - as per traction engine practice - and saw the oiler stop frequently.) I moved the oiler linkage to the crosshead where motion is constant. 3. Despite having cleaned the oiler and the lines, I found a large amount of water in the oiler reservoir so obviously steam was passing back through the oiler check valve sometimes. I was also still getting dry cylinders, sometimes right out of the gate and other times after a couple of days running. I finally replaced the single pump oiler with a new "double pumper", installed an industrial check valve in each line, and ran one line to each cylinder - NO MORE PROBLEMS! Unfortunately it took 3 months to resolve all the problems so I spent most of our short running season doing repairs and not running! I wish I had gone with new components and the optimum arrangement from the beginning but I didn't and it cost me most of a running season. Just my (bad) experience......... |
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jma1009
Elder Statesman
Posts: 5,917
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Post by jma1009 on Dec 20, 2013 10:41:30 GMT
hi brian,
re the gland packing for the ram, there is a simple way to check this is ok and that is to fill the tank only half way up the pump and see if any oil escapes around the ram when operating. the loco doesnt have to be in steam or rotating - you can turn the ratchet wheel by hand. one strand of 1/16" graphite string unwound (normally 2 or 3 strands wound together) 1 circle is all the packing required on the LBSC type. the gland is just nipped up so the ram is still free to move (check for friction with the thing dismantled by unscrewing the wheel with the crank pin on it that fits into the top of the ram. it will unscrew from the spindle as usually 7BA).
cheers,
julian
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Post by GWR 101 on Dec 20, 2013 16:23:06 GMT
Brian, not wanting to put oil on troubled waters, either by mechanical or hydrostatic means but has the thread now swung in favour of two check valves.!!! Paul.
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Post by runner42 on Dec 20, 2013 22:21:46 GMT
Thanks Julian, that's exactly the information I need. The half full reservoir test is a good indicator of packing performance, it's those little "pearls of wisdom" that are often hard to come by.
Paul I guess these posts often find their own level of what's of interest to the majority. It's when the experienced artisans begin to "agree to disagree" that it get's exciting. My view is that two is better than one, but less reliable. The maxim here is that if you add more components to a system you increase the likelyhood of failure. It all comes down to what your happy with.
Regards Brian
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Post by Deleted on Dec 20, 2013 22:56:58 GMT
Hello all----------A little "Night-time" reading for you....It's the ENTIRE section on lubrication in The Black Book........make of it what you will........note the reference on page 129 to mechanical lubricators having a delivery valve at the end of the pipe............... |
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jma1009
Elder Statesman
Posts: 5,917
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Post by jma1009 on Dec 20, 2013 23:07:07 GMT
as a slight aside, it is quite easy to connect up the check valves to an air compressor with a decent gauge (ive got quite a big old ex-WD compressor with tank and big gauge) and test these gadgets. i also do the same for steam brake cylinder release valves which i set at 10 psi. i even used the same compressor to test the gordon smith safety valve i made recently for STEPNEY.
so far as steam pressure in the steam circuit/steamchests is concerned my own locos have relatively generous steam circuits and smaller cylinder bores, so it isnt unusual for me at 90 psi to have the regulator wide open with a decent load. hence i would set the spring loaded checkvalves to be the working pressure of the loco. ive made and repaired a few mechanical lubricators and wind my own springs for the check valves.
needless to say the steam brake release valve springs are quite 'fine' and i make them out of phos bronze wire. lubricator check valve springs can be made out of piano wire (ive a large tin full of the stuff if any body wants some).
bearing in mind the cost of commercial lubricators these days and the very full instructions provided by LBSC, it is well worth making your own IMHO.
cheers,
julian
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jma1009
Elder Statesman
Posts: 5,917
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Post by jma1009 on Dec 20, 2013 23:13:34 GMT
hi alan,
the LBSC type oscillating cylinder is quite different to fullsize and acts as it's own valve. hence no need for a second check valve.
cheers,
julian
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Post by sncf141r on Dec 20, 2013 23:39:27 GMT
Hello all----------A little "Night-time" reading for you....It's the ENTIRE section on lubrication in The Black Book........make of it what you will........note the reference on page 129 to mechanical lubricators having a delivery valve at the end of the pipe............... Hagley - quick note as the wife is expected shortly (!) - but I have your reference and the 1947 Locomotive Cyclopedia beside me. Detroit mechanical lubricator - NA practice was to divide oil outputs from mechanical lubricators and lubricate as much of the locomotive as possible. Pg 709 of the Cyclopedia - Low Pressure Terminal Check Valves for use at non steam or non-pressure points… "… and it is only necessary to prevent the oil draining from the line between the oil feed divider and the terminal point during standby periods of the locomotive..." The steam-pressure terminal check valves have atomization as a part of their design. Hydrostatic lubricators - pg 718 - two pictures of a ball type lubricator choke and a brass type lubricator choke - and steam chest plugs; I'll admit that in my full sized practice (I'm licensed, but rusty, to do this) that the brass "small hole" chokes are my experience, have never seen a "Ball type check" - you learn something every day! I'll try and get these pages photographed/scanned in within 24 hours. Another JohnS. |
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Post by sncf141r on Dec 20, 2013 23:58:36 GMT
Hagley - quick note as the wife is expected shortly (!) - Not back yet! MEchanical lubricator "low pressure" terminal check valves:  Mechanical lubricator divider:  Hydrostatic lubricator terminal "chokes"  Does this help, or muddy the waters? Another JohnS |
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Post by Deleted on Dec 21, 2013 0:09:21 GMT
It enriches our lives !!
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JDEng
Part of the e-furniture
Posts: 384
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Post by JDEng on Dec 21, 2013 8:53:55 GMT
In answer to E J Parrott's question at the top of this page; if you look at pages 130 and 131 of the Black Book as posted by 4930 Hagley (thanks Alan, saved me doing the same!) you can see the ball valves at the delivery side of the pumps on both the Silvertown and Wakefield lubricators.
Julian; I agree with what you say about the oscillating pump in an LBSC lubricator and did mention this in an earlier post. Personally I would put a ball valve at the lubricator end but that's me; we all have our own way of doing things and I wouldn't condemn anyone for not doing so in that situation. A conventional, fixed pump is a different matter however.
Another JohnS; that's interesting information. I might be wrong but it looks as though it might be from an American book. The low pressure check valves will, I assume, be for axleboxes and other points which are not subjected to steam pressure. The lubricator Divider is quite a complicated device, I have a drawing of one in a book and wouldn't particularly want to reproduce it in a small scale! Basically it is designed to split the feed from one pump but ensure that the delivery pressure to two, or four, legs of pipe all remain the same so that all get an equal amount of oil. As has been discussed before, this doesn't happen with a simple tee.
I don't recall ever having seen anything about the Ball Type chokes before (except in wrestling!!) so that's a new one on me.
Cheers,
John.
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Post by ejparrott on Dec 21, 2013 9:22:50 GMT
Interesting. I've not got time to read it now, but thanks for putting it up, I'll read it tonight, but it looks like full size practice is for two check valves then? One on the pump and one at point of delivery, although I'm assuming there aren't check valve when the lubricators are used to supply oil to axleboxes etc?
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JDEng
Part of the e-furniture
Posts: 384
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Post by JDEng on Dec 21, 2013 9:44:56 GMT
Interesting. I've not got time to read it now, but thanks for putting it up, I'll read it tonight, but it looks like full size practice is for two check valves then? One on the pump and one at point of delivery, although I'm assuming there aren't check valve when the lubricators are used to supply oil to axleboxes etc? That's correct; one at the pump and one at point of delivery. Your assumption about axleboxes etc is wrong though. These also have two, exactly the same as for cylinders. Although there is not the issue of back pressure from the steam in an axlebox there is still the necessity to keep the pipe full of oil when the loco is standing. The problem in this location is establishing an oil film on the journal as quickly as possible; within one or two revolutions. You don't want to be having to refill a full pipe with oil and also you don't want a pipe full of oil draining away and lubricating the ballast. Oil's expensive stuff at the best of times and, being a Yorkshireman, "you don't want to be chucking yer brass away lad!". John. |
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Post by wdiannes on Dec 21, 2013 10:40:15 GMT
The lubricator Divider is quite a complicated device, I have a drawing of one in a book and wouldn't particularly want to reproduce it in a small scale! I have not seen such a drawing for a flow divider for lubricating oil but am familiar with flow dividers for hydraulic systems. Does the one you refer to use a rotating core with fins or veins or some other method? I am curious! |
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bhk
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Post by bhk on Dec 21, 2013 11:40:37 GMT
Has anyone incorporated a mechanical lubricator into a locomotive to do the same as full size aka slide bars, axleboxes etc etc
Cheers
Sean
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Post by Deleted on Dec 21, 2013 13:36:11 GMT
Has anyone incorporated a mechanical lubricator into a locomotive to do the same as full size aka slide bars, axleboxes etc etc Cheers Sean Hi Sean Not yet but Don Young's drawings for my build has the prototypical mechanical lubricators that sit on top of the running boards either side to feed oil to slide bars, axleboxes etc. His attention to detail in his Doncaster drawings are something to behold.. I am so. so grateful that I chose his design over others, I really am building something that will probably be as close to full size as is possible, this is probably the main reason that I am taking the detail even further as I have such a great canvass to work from...it deserves all the extras....  regards Pete |
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Post by ejparrott on Dec 21, 2013 15:23:54 GMT
]That's correct; one at the pump and one at point of delivery. Your assumption about axleboxes etc is wrong though. These also have two, exactly the same as for cylinders. Although there is not the issue of back pressure from the steam in an axlebox there is still the necessity to keep the pipe full of oil when the loco is standing. Great stuff, hadn't though about the draining aspect. Thanks for clearing that up for me! |
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Post by ejparrott on Dec 21, 2013 15:24:27 GMT
Has anyone incorporated a mechanical lubricator into a locomotive to do the same as full size aka slide bars, axleboxes etc etc Cheers Sean I'm not 100% certain but I think Doug Hewson designed the Class 4 like that |
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Post by Deleted on Dec 21, 2013 17:33:50 GMT
----------- didn't anybody look at Page 129 then ??
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I found:
