Just to introduce myself Modelworks 9F restauration project.

[jma1009]

hi peter,

for a 24 oz pm injector DAG Brown and Laurie Lawrence recommend a steam passageway through the steam valve of 3mm. 24 oz pm equates pretty much with a Maidstone No.4 injector 1 1/4 pint pm. it is always advisable to have a few spares anyway, and often you will find that 2 injectors the same size from the same firm have different pressure operating ranges, so one can mark them accordingly and use a high and low pressure one. if i were having to buy an injector i would contact Polly and see if they can supply you with a gordon chiverton injector 24 oz pm or less. (usual disclaimer). but beware gordon's 12 oz pm injectors are 1/4" x 40 TPI thread connections not 5/16" x 32 TPI that will be on your pipework. gordon's injectors also have a flat nipple not a cone connection for the water inlet. if you know what you are doing and make a special countersunk bit to suit the coned nipple the injector body can be modified - but on no account do this till you know what you are doing! (perhaps best to ask someone 'in the know' to do this for you or ask Polly to do it for you)

like john i make my own so dont have to buy these things!

have you made a proper water feed for the injectors yet or is the supply still coming via the tender handpump?

cheers,
julian

[peterdebeus]

Hi Julian,

Thank you for your answer,

Yes i have the pipework moddified now, both injectors have their own water suply, with a valve inside the tender fitted.
They also both lift water into the boiler, only half of the water comes out of the overflow, and when i turn the water level down
it just blows steam again, but they work all the time, turn the water on, turn the steam on and its working.
Only i dousnt make the ''chilping'' sound it should make, and there is a lot of water from the overflow..
My pipework also has a flat connector for the injector water suply,

So its looks like the injectors do work, only the water dousnt want to go into the boiler fast enough...


so I will first mesure the clacks, to be sure they have enough lift.
After that i can go ant find some good new injecotors.

[jma1009]

hi peter,

next time you steam the loco, and when pressure is say 60-70 psi, try the injectors and when they are 'working' as you have found, slowly adjust the water supply valves reducing the water flow and let us know what happens. dont do this with low steam pressure. i agree with john re inadequate lift on the clacks, and inadequate steam valve passages, but it is also just possible that the water feed is far too great and the injectors are not 'self regulating' re the water supply. i had a similar problem with a 7.25"g loco where no one could get the injectors to work properly till i had a go - the water valves were far too big, and reducing the water allowed the injector to feed cleanly. in future no one opened the quarter turn water valves more than 45 degrees!

'chirping' is actually a sign of the injector sucking in air which it shouldnt! so dont worry if they dont chirp!

cheers,
julian

[Deleted]

Hi Peter,

I'll second Julian's recomendation for a Gordon Chiverton injector. I do have a 12oz (No.2) one that a friend gave me and it's always been very reliable. The smaller injectors are a bit more finicky than larger ones though and you need to keep them clean.

Incidently, an injector shouldn't really 'chirp' when it's working - it should be silent. The chirping noise is air being drawn in to the injector through the overflow which then mixes with the feed water. Not a problem with a copper boiler but not good for a steel one. Usually happens when the water flow is slightly restricted (water valve might be closed too much) but the injector still functions and puts water into the boiler ok.
(Julian beat me to it!

John

[peterdebeus]

HI Julian!

I already did reduce the water suply, this is how i get them to work:
First i fully open the water suply, till they start dripping from the overflow.
After that i open the steam suply and you get a big gush of water.
Then i turn the water valve down, and you can hear the injector turning on, thats ok so far.

after that, when i turn the water valve down more while the injector was working.
It suddenly stops working and only steam blowing out, even when there is still a big
amount of water comming from the overflow.

Last night i was thinking, the silicone hoses, they get a lot of vaccuum when the injector
suck realy hard, and the water suply valve are closed, they are realy soft material.
Could it be that the injectors are going off because of the silicone hose gets flat by vaccuum.
I think i have to check this to, and maby fit some rubber hose to be sure thats ok to.

I remember from the first time i fired it and tried to open the steam suply from the injectors, when it was connected to the feed line from the axle pump, that i could see the silicone hose go completely flat.

[jma1009]

hi peter,

thanks for that clarification.

it is possible that the flexible hoses are made of material that is too thin. silicon of its self shouldnt be a problem - we use silicon hose on the vacuum flexible pipes on our ground level stock. a cheap source of tubing is clear plastic tube used on fish tank pumps etc. pop down to your local aquatic suppliers and see what sizes they've got.

cheers,
julian

[peterdebeus]

I also have some thicker, i have some different type of hose where i work.
Will test with some thicker hose, to see if that solves the problem.
The one on there now are verry soft, (easy to fit).
I didnt knew they would create that much vaccuum.

Tonight i will mesure the clack, see if they have enough lift.



If thats ok, they should working, i dont realy think the injector self are the problem....

[jma1009]

hi peter,

when you take the clack valve caps off a picture of the insides with the ball removed would be very interesting. to remove the ball use a piece of small flexible hose or a straw and suck to lift them out! do attach a toolmakers clamp or something similar to the clack valves as you free the caps

good luck!

cheers,
julian

[peterdebeus]

Ok i will Julian! thanks

[peterdebeus]

I have removed one of the clacks, and took it appart to mesure everything,
the housing is 11mm deep,
the cap 5.5 mm mesured from the where it hits the edge of the housing ofcoars.

the ball itself somewhere around 4.7mm

that should say it has 1mm lift +-?

[peterdebeus]

i tried to make a picture of the inside with the ball fitted in there.

[peterdebeus]

i was thinking, i could try to fit a fibre ring underneed the cap to give it some more lift and see what happens?

[jma1009]

hi pete,

have you got a dremel engraver with some dental burrs? i would be inclined to radius the entry to the exit hole without damaging the seat of the clack valve. i usually tap the thread for the cap in the check valve as far down as possible without damaging the seat, or relieve the area below the thread a bit without allowing the ball to 'wander' as it lifts. 1mm lift is a bit too small for my liking for an injector clack valve of that size - though the easiest way to check is to blow through with the cap fitted without the ball, then add the ball and blow through again and see if you feel any restriction. also stop blowing and suck with the ball in place and see how quickly the ball seats then blow again. you will soon get a 'feel' for these things and what's right and what's not.

if you fit a washer to the cap it wont be much. sorry im not very good with metric - but 0.5mm might make all the difference between feeling a restriction when blowing through, as to none at all. (try the cap raised by 0.5mm to start with to see what difference that makes when blowing through). i would suggest making up a few PTFE washers at work (see a previous thread of mine!) as then you wont have to tighten them much - just 'nip' them up, and they will be easy to undo if ever they need removing at a later date.

generally for 5"g 1/32" lift for axle pump balls, and 3/64" for injector balls. under no circumstances must the cap restrict the exit hole from the clack valve.

the pics by the way are excellent and very good!

cheers,
julian

[peterdebeus]

HI Julian,

Thank you, i know what do do now, i will try and do some more testing.

I also have a water pump from a car wiper/washer thing, not sure how you call that?
Also use this to fill the boiler, it gives quite a lot of water, i was already thinking
to use this to see what happens when i connect this to the clack.

For testing its quite easy, i can just screw that cap up a bit 0.5-1mm and blow it, it will still seal quite well.

I have tools, as my other hobby was tuning race engines so i have lot of small tools
to do this, so i need to make the flow better and see if i can make some improvements there.

will do some more tests and will let you know.
I was also shocked of the quality of the pictures haha, with 0.0000 experience in doing photograps!

Peter

[peterdebeus]

Yesterday i have put back together the clacks, and was looking with a small lamp inside the hole to see the ball with the cap fitted, i could see the edge of the cap, and the ball in there, and there was about 2mm of space between them, so that should be good, so i did not do anything with the cap.
If i blow on it, it flows verry free.

Only thing i found when looking in there was that the ''intake'' tube are almost 3mm and the ''exit'' tube
is 2.5mm, so i drilled the exit 3mm to, this helped a bit to make it easyer to blow air trough.

And i found that the cone, soldered on the pipe from the injector had a lumb of solder in there
blocking aproxematly 1/4 of the pipe, so i took that away with a little grinder.

The other clack and injector + its pipework looks all oke, i just drilled the exit hole to 3mm to.
So i think i just need to test with better hose for tender connection, and see if i can control
the suply more easy.

Also i made a small hole in the frame, and fited a connector in there
this to fit the hose from the tender hand pump.
At first it was just a pipe fitted to the clack, and from there a rubber hose to the tender piping.
It was not suported anywhere on its trip to the back.
but i can imagine when driving at some point the clack will come loose when the tender is pulling at it all the time, and pussing the rubber tube on there and pulling it off again also dousnt help.

[Deleted]

Hello Chaps ---------- PETER, that lump of solder blocking 1/4 of the pipe would have been the main culprit I think... Julian and BAGGO have referred to the importance of keeping the feed water clean, free from air and flowing without restrictions....So no kinks in the flexible pipes or tight bends in the copper ones...

[jma1009]

hi pete,
i agree with alan re the restriction you found re the solder, and you did very well to spot this! well done! i examine carefully and blow through all my pipes after silver soldering nipples on etc just to check - obviously this simple elementary proceedure wasnt carried out by Modelworks though im not really surprised. suspect the worst and check everything if you havent made it yourself!
cheers,
julian

[peterdebeus]

Hi Julian and Alan ofcoars!

Thank you, yes i hope this will improve the injector working.

I am working at a company selling and maintain CNC machines and Lathe etc, i work as a mechanic.
At those machines (who work verry accurate till 0.001mm) you also have to work verry accurate.
And you find the most strange things when something small (almost invissible) will be not OK.
I realy like to inspect everything verry well and try see and understand how everything works.

BTW I am not sure if this pipework was all build by modelworks.
What i maby did not tell over here, was wat we found out during pressure testing.

The Boiler on my engine isnt a modelworks item, it has a JL3 stamp in it and a Nothern federation number.
Its not a comercial build boiler, but done by MR J Llewellyn.
WHY? i realy would like to know why they changed the boiler, realy no idea about this.

Also all the motion work was not the origional items, i took this appart to check for smooth running and just to see how it was made, and it looks quite well to me.
and all the steam valves are already changed by myself.

So i think most of the problems should be overcome by now (fingers crossed) haha

[Deleted]

Hello Chaps------- That's interesting to say the least !!I've just been re-reading your posts when you and your Boiler Examiner visited Station Road Steam to view this 9F....Maybe they can contact the previous owner on your behalf to get some background information ??--- My guess is this boiler was a Pre-production one at the time of its' manufacture and Modelworks employed this chap to build a job-lot to proof-test their tooling before mass-production was commenced...Maybe this loco was an "End-of line" job using whatever parts were available ??.......... Just a few thoughts to consider....

[peterdebeus]

yes i think this is realy strange to, i think the inspector dindt say anything about that, he only looked if it was ok to get it checked.
And he had contact with the previous boiler inspector, from the UK, and it was all ok.
For him it was not important if it was a CE boiler or not, i only asked him to look if everything was ok for me to get a dutch certification, and it was...

I have already had contact with the model club where he was a member, and he has moved to south africa with no contact details......
Also with the boiler inspector from the club over there, who is an old friend of one of the members of my local club (small world).


I am going to italy now, see you all next week!