Can you test a Superscale economy injector on air?

[Chet]

I'm having a problem with my Superscale economy injector on my Allen Mogul.
It's worked great since the engine was originally finished in 2001.
I've only done intermittent running during the summer since then.
But this last 'fire up' after my boiler test has me wondering what may be wrong.
Normally I'll turn the tender water supply on full, and use a ball valve to turn on the steam almost instantly.
I then adjust the water supply to a minimal trickle while the boiler refills.
This time, though, I'm not getting that full flow of water to start with.
So here's what I've checked:
The water from the tender is flowing to the injector.
The check valve on the boiler is working correctly.
Disconnecting the water supply, I can feel the vacuum from the injector.
I've replaced my injector with a new replacement (I bought two originally, but have been only using one.)
And filled the boiler with compressed air to 95 lbs pressure.
BUT the same problem occurs.
Will injectors work with compressed air? Or is steam necessary?
Thanks for any suggestions....
Chet & #9401

[AnthonyDuarte]

Chet,

Injectors won't work on air. You may be able to draw water up to the injector body with air, resulting in a light mist coming out of the overflow, and that's where it ends. The rapid condensation of steam back into water is critical to their operation.

It sounds like the original injector may have dirt in the cones, which would prevent the injector from drawing in water properly on startup. If the replacement injector has only been tested on air, then... well, there's your problem. Give it a test under steam, and if you still experience problems, the most likely suspect would be a vacuum leak somewhere in your water line. Any air getting into the water line will cause your injector to dribble or just simply not work at all.

Hope this helps,
-Anthony

[ChuckHackett-844]

No, injectors work on the physics involved with steam.

Do you dissassemble it and soak in white vinegar each year? Take out at least the exit cone and washer. Be sure the washer moves freely and the tiny holes in the cone are not clogged. DO NOT USE HARD WIRE OR DRILL BIT to clear the holes ... at most use single strands of fine copper wire.

[Chet]

Thanks, Anthony and Chuck, for the valuable info!
I'll wait until the next steam-up and try it again.
If it doesn't work, I'll go the substitution route....
Rules of thumb can be tricky, but would 20 min in vinegar typically be sufficient to clean up the injector?

[Vance Nickerson]

The washer is stuck. Skip the vinegar remove the bottom plug reach in with a 5/16" socket and remove the cone and washer. The washer should be stuck to the top of the cone, work it off use care not to drop it. Use fine sandpaper or scotchbrite to clean the tip of the cone so the washer will move freely. Insert washer cup side up after cleaning the cone out some wd40 on the threads and reinstall the cone and plug done. Less than 5 minutes trackside and back to running. Don't loose the washer! I lost one at the first triennial and only had one injector the rest of the ramble.

[ChuckHackett-844]

20 minutes in vinegar is a good start (depends on how much scale buildup you have).

I would not use any abrasive as suggested by Vance. This approach done year after year will damage it. The vinegar will accomplish the task without danger of taking metal away.

If the washer is stuck on I'll bet, after the vinegar treatment, the washer will fall off.

[ChuckHackett-844]

In case I wasn't clear: the 'vinegar treatment' is done on the parts after disassembly.

Remove the injector, remove the bottom cap, remove the exit cone (the washer is on this) using a thin-wall socket, etc., remove the steam cone from the top using a screw/bolt that threads into it (I forget the thread at the moment).

As mentioned, there can be no air leaks in the suction side and it must be as free-flowing as possible (larger pipe, no 90-degree turns, etc.). The exit piping should also use 45-degree fittings in place of 90-degree when possible.

After putting a new boiler on an engine the injector was not working, I discovered a metal shaving lodged in the steam cone. removed the shaving and all was well.

[Chet]

Thanks, Chuck, for the clarification.
I just finished the vinegar soak with the unit assembled....
But then it's Monday..... ; - )
I'll try it again with the unit disassembled.
And thanks for tip on removing the steam cone...
I'll see if I can figure out the thread size.
Thank you for the follow-up!
Much appreciated.
Chet & #9401

[Chet]

Hi Chuck!
The steam cone on the top is a 10/32 thread.
I screwed in a bolt, but cone is really resisting!
I've sprayed it with some penetrating oil, but it is still holding tight.
What method do you use to free it up?
Chet, #9401

[ChuckHackett-844]

In the car at the moment (wife driving ).

Arrange something on top of the injector that the 10-32 screw will pass through but will not damage the injector/threads.

Put a nut on the screw then pass the screw through the block/whatever and screw it all the way into the steam cone.

Tighten the nut and it should extract the steam cone. If you feel you are using excessive force skip it and soak it in place. It's the least critical of the two.

When reassembling be sure you get the washer correct side down - it makes a difference! Use anti-seize compound on all threads/mating surfaces.

[Chet]

Thanks, Chuck! Safe journey.....
Chet, #9401

[Dave Bortz]

Hi Chet;
Good advice by all... Some things I can add...
Barry recommended spraying all the threads with penetrating oil prior to disassembly. I recommend, for season to season reliability, disassemble the injector to at least ensure the washer and check poppet stayed lubricated for the winter. When they dry out, deposits remain making parts freeze together... so some good light penetrating oil, liberally applied on them will ensure they work when you want to use the injector again. Its also recommended to apply some steam oil on all your valve stems and run them in and out a few times, leaving them off their seats, especially when laying up when the boiler and piping is still hot. The thermal contraction as the equipment cools is a huge force that can break small parts and damage valve seats.
Good luck with the injector and send me a PM if your having further problems with it.
Safe Steaming
Dave