jma1009
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Post by jma1009 on Aug 18, 2015 22:32:49 GMT
this subject is a bit a mystery for some.
in my area of south wales it isnt a problem, unless you havent fitted filters to the water supply side from tanks or tender. i used to live on the south coast where hard water was a constant problem in miniature loco boilers.
1. always fit a fine screen mesh filter to the water supply. the finer the mesh the larger the filter needs to be in area. i have always used very fine stainless silk screen printing mesh
2. make sure your steam valves and check valves dont leak
3. in theory an injector should be self cleaning in that the steam and condensed water scours the cones.
4. in 32 years i have never had to change an injector whilst a loco is in steam on a track so have never had an injector 'fail'. however i always have a spare in the toolbox just in case!
5. if you need to clean an injector, use citric acid rather than vinegar as vinegar can leave a mucky residue. i use ordinary sainsbury's lemon juice from the bottle as it's a standard strength, for 6 hours.
6. dont just dunk the injector in the citric acid. firstly remove the steam and delivery cones at each end. remove them carefully and a special tool may need to be made for this job. the injector minus steam cone and delivery cone is dunked in the acid and swirled about to remove air bubbles. add the steam cone and delivery cone and treat likewise gently.
7. never ever poke any metal through any of the cones!
8. after soaking in citric acid and blowing through check carefully under a strong light. remove any crap or debris with the point of a wooden cocktail stick. use a loupe if your eyesight isnt too good
9. the seating of the check valve can easily be tested by inserting the end of a cocktail stick up the delivery end of the combining cone and then sucking through the steam entry end, blocking off the water entry with the thumb, and forefinger on the outside of the angled check valve body. remove the check valve cap first using a precision toolmakers clamp rather than a spanner. this is how DAG Brown describes it though i use a rubber plunger.
10. i have found all sorts of crap in injectors from dead spiders remains to swarf and old flux deposits. scale of itself shouldnt cause a problem see 3 above.
however a leaking clack valve or steam valve is the cause of most problems.
11. when re-inserting the steam cone and delivery cone make sure you get them in the injector body the right way round! if in any doubt make a sketch beforehand or mark the injector accordingly.
cheers,
julian
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jma1009
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Post by jma1009 on Aug 18, 2015 23:56:38 GMT
apologies, i should have added
12. if you have a tender loco, when steaming up and before coupling up the tender full of water, open the water valves on the tender to clear the filters plus any coal dust or muck that may be in the end of the rubber etc pipes. it is good practice to fit plugs on the end of these pipes when the loco isnt in use AND before cleaning down.
13. it never ceases to amaze me how many people say 'my injectors wont work'.
'have you got filters?' i ask.
'no, i havent fitted them yet'!!!
on a standard medium size (26 oz per min) injector there is an annular gap of 8 thou around the steam cone protruding into the first half of the combining cone. it doesnt take much to block most of this annular gap. on smaller injectors the filter must be VERY fine to avoid any problems plus be of large area to allow a sufficient flow of water.
cheers,
julian
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Post by springcrocus on Aug 19, 2015 6:20:29 GMT
Thank you, Julian, for taking the time to write that up for the benefit of all. Too often, when one asks a question, the answers tend to be short and concise without any of the detail needed to fully understand what is going on. People often forget that there are beginners as well as experienced people reading these posts and an in-depth description is always valuable.
Steve
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Post by Cro on Aug 19, 2015 7:16:03 GMT
I have always used an ultrasonic cleaner that has a specific cleaning solution (can't remember what it is now) that dad uses on the clocks and watches - I only ever remove the clack bung and ball and leave the cones in place. It would probably work well with just water or even citric acid as you have said.
Great tips there Julian!
Adam
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smallbrother
Elder Statesman
Errors aplenty, progress slow, but progress nonetheless!
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Post by smallbrother on Aug 19, 2015 7:42:40 GMT
Any tips for removing cones? They are usually stuck firmly in place on the locos I have bought.
Pete.
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jma1009
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Post by jma1009 on Aug 19, 2015 9:04:51 GMT
hi pete,
dont ever use a pair of pliers or a drill chuck! many years ago i made up a set of tools that look like return cranks with a split and bolt to tighten them, bored to various sizes.
the reason i remove the steam and delivery cones to clean the injector is because often debris is found which isnt ordinary scale. i should have added above that i also remove the cap and ball. if you cant see inside the injector you wont know what debris there might be inside!
also removing the steam cone and delivery cone ensures the citric acid penetrates fully. you dont want air bubbles inside stopping it doing its work.
i have 2 brand new commercial injectors in front of me that contain brass swarf! i am not aware that citric acid or adam's ultrasound method will remove the brass swarf from between the cones!
cheers,
julian
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mbrown
Elder Statesman
Posts: 1,723
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Post by mbrown on Aug 19, 2015 9:55:42 GMT
For those like Julian who have connections with the Talyllyn Railway, you may be interested to know that we are having a good deal of trouble with injectors at the moment due to the boiler treatment furring up the cones quite rapidly. The treatment is exactly as Julian suggests - remove the steam and delivery cones (on our 4mm and 5mm Gresham and Craven injectors they are held in place with a set screw so no special tools needed)and leave to soak in a bath of citric acid. I am sending this from Pendre and am about to take No.4 Edward Thomas off shed after just such a treatment - hoping we'll get through the day with working injectors.
The boiler treatment in use at present is doing good things to the insides of the boilers but the injector problem is a side effect we hadn't bargained on. The water here is acidic but pretty free of scale.
If any one is using boiler treatment in a miniature loco, and gets injector problems, it may be worth exploring alternative treatments.
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Post by mattscrutton on Aug 20, 2015 7:29:35 GMT
I haven't used acid to clean injectors for years. I have never been happy with subjecting the cones to that sort of treatment. I invested (£30) in a ultrasonic cleaner. Ten minutes in that and the injectors work like new, and all they sit in is water. I regularly get asked to clean peoples injectors with it.
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gwr7800
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Post by gwr7800 on Aug 20, 2015 10:36:26 GMT
Julian a most interesting post! Especially just recently with my problem injectors, this might seem a daft question but do the steam cones in a injector wear? They are so fine on the end just wondering. Cheers Chris
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jj
Active Member
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Post by jj on Aug 20, 2015 10:44:51 GMT
I've been having problems with overflow on my 24oz Chiverton injector recently, after five years of trouble-free running, and as mentioned in a recent thread I cleaned a lot of limescale from the top feed on the boiler and assumed that this would solve the problem, but it didn't. Following Julian's advice above, I removed the steam cone for the first time and found that the end is quite badly worn away as shown in this photo. This presumably explains my problem. I have fine brass mesh filters on the water pipes and I use citric acid to clean the injectors - half a teaspoon of crystals in a small jar of warm water for 20 minutes or so, 3 or 4 times a season for 5 years. Has the acid eaten away the very thin wall of the cone? I assume that this cone is a write-off, and I believe that the excellent Chiverton injectors are no longer available, so I'll need to buy something different. I'll check the 16oz injector which I used far less frequently but cleaned just as often - this may indicate whether the problem was caused by the citric acid or abrasion from particles in the water.  Regards, John Edit: I think this picture answers your question, Chris! |
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Post by mattscrutton on Aug 20, 2015 10:53:18 GMT
If you want a good replacement john buy a Steamfittings injector. They work well and put up with all manner of punishment
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Post by Roger on Aug 20, 2015 10:54:40 GMT
Why not make a new one?
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Post by Cro on Aug 20, 2015 11:20:23 GMT
Len Steel now makes the Chiverton injectors and they are just as good. He may be able to make you a new cone.
Adam
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jma1009
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Posts: 5,901
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Post by jma1009 on Aug 20, 2015 11:48:56 GMT
hi john,
ive sent you a PM.
hi chris,
in fullsize, injector cones do wear over time. it is not something ive come across in miniature.
cheers,
julian
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gwr7800
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Post by gwr7800 on Aug 20, 2015 12:45:21 GMT
Yes John it does, that's exactly what I was referring too. Julian do you think this is due to wear or cleaning? John iam putting two and two together re the pm from Julian I took Julian's offer up! Cheers Chris
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mbrown
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Post by mbrown on Aug 20, 2015 13:16:17 GMT
Len Steel now makes the Chiverton injectors and they are just as good. He may be able to make you a new cone. Adam Adam - who supplies these? I'm after a replacement for the Chiverton injector on "Lyn" and gave up ever locating one. Malcolm |
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jma1009
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Post by jma1009 on Aug 20, 2015 13:27:43 GMT
hi chris,
on your 'wet injector' thread i pontificated as to the cause of the problem on 13th july by providing the 'text book' answer, and as you know the problems turned out to quite different! so i am going to try and avoid jumping to conclusions this time. however i think there is a big clue in John's description.
cheers,
julian
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jma1009
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Posts: 5,901
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Post by jma1009 on Aug 20, 2015 13:33:15 GMT
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Post by Cro on Aug 20, 2015 14:20:04 GMT
Len Steel now makes the Chiverton injectors and they are just as good. He may be able to make you a new cone. Adam Adam - who supplies these? I'm after a replacement for the Chiverton injector on "Lyn" and gave up ever locating one. Malcolm If you can get hold of Len's details then best go directly to him rather than through previously mentioned above but I won't go into that here..... Adam |
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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 Aug 20, 2015 16:41:23 GMT
Adam - who supplies these? I'm after a replacement for the Chiverton injector on "Lyn" and gave up ever locating one. Malcolm If you can get hold of Len's details then best go directly to him rather than through previously mentioned above but I won't go into that here..... Adam I am not sure why you say that. Paviersteam is Len's choice for selling his injectors. I imagine I will see Len and Paul Pavier tomorrow at the Llanelli club's gala. The injector's were displayed on sale last time. Pete. |
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