Need help with injector problem...

[Chet]

While steaming up for the Lake Shore Live Steamers (NE Ohio) public run, I discovered that my water injector was not working correctly.
I normally turn on the water, turn on the steam, and then adjust the steam so the water is at trickle.
Today it was all or nothing: either all water, or all steam.
The initial thought was that my check valve to the boiler was leaking...
I dumped the fire, blew down the boiler, and checked the check valve.
All OK. At least when I blew into it from the boiler side. No leakage.
I then installed a new injector (I keep a spare), and exactly the same problem.
Possibly related, my lubricator was back-fed steam and emulsified the oil...
Checked both right and left lubricator check valves, no apparent problem.
Now I'm wondering what could be the real cause of my water injector problem...
Injector checks OK, the check valve checks OK, the water supply is OK...
What am I missing???????

[Fred_V]

While steaming up for the Lake Shore Live Steamers (NE Ohio) public run, I discovered that my water injector was not working correctly.
I normally turn on the water, turn on the steam, and then adjust the steam so the water is at trickle.
Today it was all or nothing: either all water, or all steam.

the problem may be that you are adjusting the wrong valve. do it as you say but when you get all water from the overflow you should cut back on the WATER valve. the operation is that the water should condense all the steam into water. if there is too much water the excess is dumped out the overflow. cutting back the water supply will bring things into balance.

if you turn on the water then the steam and get all steam from the overflow there is a good chance that you have an air leak in the water supply line. the other thing it look is there may be crud blocking the delivery cone. remove the cone from the bottom and look through it form the end as well as from the side at the little holes. clear any blockage with a tooth pic very carefully starting from the top. you don't say what injector you are using but most of them work the same way; or fail the same way.

[ccvstmr]

...Fred, you forgot to add...
1) if you can see light thru the holes in the cone...they're clean.
2) don't drop the check valve disk (assuming a Superscale injector). They get lost in rocks and cinders easily. And a magnet won't help you find it (not ferrous metal).
3) note the raised ridge on that check valve disk. If I remember right, the raised ridge on that disk faces "UP" on the stem as that is the sealing surface.
4) make sure the disk slides up/down on the stem easily after you're done cleaning out the holes in the cone.

Hope this helps. Carl B.

[Chet]

Thanks for the feedback guys, and I did say something wrong in my first post... I DO turn down the water, not the steam, when the water begins being injected.
As far as the injector and cones go, I replaced the old injector with a new SuperScale Economy ejector and had the same problem.
It's either full steam or full water, no adjustment on trickle.
The unit has been working fine for several years now, and this is a new wrinkle...

[Mike Walsh]

Try making sure the check valve is working properly. I've had this issue, and I've tapped on the check with a wrench lightly... If it's sticky, it'll unstick.

We used to have several extra on hand that we'd swap them out as needed... very carefully. 'Course, we take about 4 hours to fire up...

Mike

[765nkp]

Try using a clear water hose to the injector so you can see the water to make sure your not sucking air, I had this same problem a few years ago, swaped injectors same problem. Found it was sucking air from the water valve stem in the tender. The packing nut on the stem had worked loose, tightened and all better. That was after I spent alot of time checking everything else.
Tim

[John_S]

Another method to check for an air leak I've seen done is to fill a small bucket or pail with water and, with the injector running, immerse the injector (plumbing and all) into the bucket of water. If it picks up and begins delivering then you know you're getting air in the water supply side.

Of course this is only possible if your injector is open enough on the side of your loco to get the bucket of water up around it.

[Fred_V]

you can also hold a water hose against each fitting and flood it with water to see if it makes it start working. since it was working before something has changed!!?? be sure that disk is turned the right way as was suggested; it's easy to put that back wrong. also check the steam cone to be sure it isn't partially blocked.

if all that is OK there must be an air leak somewhere in the water feed.

[Phil Tucker]

Try using a clear water hose to the injector so you can see the water to make sure your not sucking air, I had this same problem a few years ago, swaped injectors same problem. Found it was sucking air from the water valve stem in the tender. The packing nut on the stem had worked loose, tightened and all better. That was after I spent alot of time checking everything else.
Tim

The same thing happened to me: a clear piece of hose just before the injector revealed the presence of an air leak as tiny bubbles flowing along with the water, which I eventually traced to the water valve in the tender. If your injectors and check valve are all in working order, and the system has worked fine for years until now, then an air leak is the most likely culprit.

[Chet]

Thanks, guys, for some really useful info!
I'll starting checked out sources of a possible air leak.
I'd never have considered the possibility of the bonnet screw on the water valve being too loose...
I'll post what the final solution turns out to be...
Chet