A few months back there were threads related to injectors and trouble-shooting injector problems. We were asked by a number of RYPN readers to discuss injectors in an upcoming video.

The video is out. It is our hope that you will take a few minutes to view the video.

http://www.youtube.com/watch?v=PvVZw-0MDp0

It is interesting to note that our videos have been picked up all over the world thanks to viewers here at RYPN. It is our intention to continue producing the videos and we are always looking for topics that are of interest to groups like this. If you have video suggestions or questions, please let us know.

We hope you enjoy our latest video.

Kindly submitted:

Great video and a wonderful way to spread the knowledge.

Steve

Nice video John. At first glance I was wondering what Glenn Beck was doing next to a steam engine, but then I recognized you.

Good video. Please, please get a wind screen for the microphone!!!

Howard P.

Good grade school explaination of the venturi efect, but I didn't hear a word about condensation, mass, volume and density - all of which are as critical and integral as the development of velocity. Maybe it was too simplified? I know a lot of firemen who can operate an injector but have no idea how it works, so maybe it isn't necessary to go into greater detail, but how to operate an injector wasn't included either. I suppose I'm wondering what the purpose of this is.......

dave

The whole point of this is so people like myself understand the basics of what an injector does, i dont intend to fire a locomotive so have no need of knowing how to use it, thats for fireman in training.
Well done John these are great, thanks for your time.

Mike Pannell

If it did that, Mike, I'd not be confused. I'm left wondering if the scriptwriter knew how injectors worked, or knew how to communicate what he knew about how injectors worked, and given the theme was supposed to be troubles with injectors I wouldn't know any more about diagnosis and repair after viewing than before.

John has done more than most people about sharing information and bringing worldwide standards and practices into the ongoing discussions about our work in the US, and I'm more than grateful for it, but this doesn't seem to be a well thought out exercise in education as much as a good promotional effort, not that there's anything wrong with that either, provided that's understood from the start.

I know he can do better if he really wants to impart the full story in understandable language, so it just doesn't add up from my POV. He's a detail oriented practical problem solver, but maybe just not with making good movies?

dave

Ok guys, no need to start a big debate over this one and I hope to end it right here, we all have better things to do and preserve!

Dave, you and I know each other and your comments are very kind. I will lay the cards face up on the table here. Our goal with the videos is to impart some knowledge and to insight some discussion to which we can explore even more topics. Based on the comments we have gotten on this video, we have shared some "not so common" knowledge about injectors without putting the discussion so high that we lost people, but not so low that we board viewers to death.

You will note that at the beginning, I promoted Strasburg and Back Shop Enterprises, so, I am making an effort to share "promotion" with everybody, even though I do not need to as these are my videos. I am proud of the fact that indeed Wasatch has Pioneered the use of this media in this industry and there is something to be said for that.

Am I a great script writer? No. Could this video have been more in-depth? Yes. However, it is like the never ending conflict about the guy who comes up to you at a train show and tells you all about his model of the "such and such" and how detailed it is and then, the same guy goes on to tell you what is wrong with your FULL SIZE version of his model and the discussion ending with me saying......"so, show me yours....you have seen mine!" The guy walks away all mad because of his deflated ego.

I criticize my own videos.....you want a list of minor mistakes I made, I am happy to share them, however, just like the above example....."so, show me your (video)....you have seen mine!"

Here it is face up. I (we) like making the videos, we are getting good responses. I am trying to balance length, information, story telling, fun and attention span all at once. It is a tough task but one that my staff and I are enjoying. You should see the over three hours of footage we have scrapped so far! The injector video, ONE TAKE...done. Yea, could have been better, we are taking notes and they must be getting better......our first video still has less views than this one, our 6th video. People are watching, people are learning, we are exploring the media and we will keep working on getting better.

If you have other suggestions send them to me direct. This forum is about preservation and information and that is all we are trying to share. We will keep it up and we hope to keep getting ideas on how to improve.

Dave, I would be more than happy to have a more in-depth, intellectual conversation about injectors if you wish...I think we would both enjoy it actually!

Thanks again for all of the great comments. Our next video will be out in a few weeks and will focus on the work here at the WRC shops.

Kindly yours,

You did a good job John without putting anyone to sleep, but explaining the basics. I hope you keep making these as I can refer folks to your videos when they ask me questions.
I'm anxiously looking forward to the six part series on setting valves.
Don Wirth

[quote="Frisco1522"]You did a good job John without putting anyone to sleep, but explaining the basics. I hope you keep making these as I can refer folks to your videos when they ask me questions.
I'm anxiously looking forward to the six part series on setting valves.
Don Wirth[/quote]


Or setting safety valves including dialing in the blowdown rate.

Good Job, John.
Emphasizing a couple of more in-depth concepts related to water mixing cones and nozzles wearing.

One of the common causative factors I see repeatedly is simply rusty or sediment laden water in tender tanks. It doesn't sound like it would be much of a problem, but add the high velocity of the water in the injector as the steam accelerates the water flow. It becomes a water abrasive blaster. The smoothness and geometry of nozzles and cones is very important for the injector to function properly. Take away some material, and the shapes change. Like an airplane wing that is distorted by ice, it stops functioning and the airplane no longer has sufficient lift.

Similarly, Calcium and Magnesium are inversely soluble minerals contained in hard water.
By the description ' Inversely Soluble ' , as the water is heated, the minerals tend to form a scale deposit at the instant the heat is applied, and on the heated surface. Most of us are familiar with boiler scale on firebox plates and boiler tubes. The same material is deposited on those geometrically critical nozzles and mixing cones. Sound familiar ? Like the airplane wing again, this time with material deposited rather than removed, the shapes become distorted, turbulence rather than smooth flows result, and the injector becomes unstable. It wants to ' break ', spit back the overflow, and fails to deliver reliably against boiler pressure.

Solutions...
1. Keep the tender tank and it's supply clean.
2. Use filtered and softened water.
3. Use a water treatment that will clean and prevent hard water scale from occurring,
even under varying conditions and multiple water quality sources, if necessary.

Thank you very much for building on the topic. I agree 100% with the comments and wish to add yet another problem with what we can call Hard Water, or, the water situations you have explained so well.

In the event that a starting valve is blowing by, you will end up with a condition where by the water is actually boiling, or percolating with-in the injector body. This slow boil will actually build mineral deposits with-in the body of the injector. This is due in part to poor water conditions and then the fact that the water is being boiled with-in the injector, leaving the mineral deposits with-in the chambers of the injector.

While performing duties as a CMO, I made it a common practice to remove injectors at least once per year and soak them in a mild acid to remove any scale that may have formed on the interior of the injector. Vinegar and water work well. Be careful not to allow injectors to sit too long in the solution, this method of cleaning can actually go backwards if the chemistry of the water is wrong or bad. I know of many other RR's that apply this same practice with good success. Every injector that we rebuild or clean is given this treatment under controlled circumstances and then steam cleaned inside and out before inspection and re-assembly.

Great discussion and thank you for adding to it!

John,

I have to admit up front my recent experience with injectors is limited to my 7 1/2 " live steamer. I have a lifting injector on my steam engine thatI have been told uses the bernoulli effect to raise the pressure of water stream to above that of the boiler pressure. In other words, it is the pressure of the water coming out out injector that allows it to flow into the boiler.

The non-lifting injector you described seems to work differently, using high pressure steam to crush the water and raise the speed of the water high enough that it is rammed into boiler. In other words its the speed of the water not the pressure that forces the water into the boiler.

Is that correct?

John ,

I just thought of another question.

If the injector is using the speed of the water, not pressure to force water into the boiler, is the pressure in the line between the boiler and the check valve lower than the boiler?

Penberthy still manufactures injectors of the lifting type in pipe sizes from 3/8" to 2 1/2". A good source of information can be viewed at the Penberthy web site.