Steam water pump vs. steam injector

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hottshot65
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Steam water pump vs. steam injector

Post by hottshot65 »

Greetings,

How do the two stack up against each other? What are the pros and cons?

Thanks,
Gerry
Gerry
Council Bluffs, IA

0-4-2 Chloe
Burlington Northern 7188
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tsph6500
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Re: Steam water pump vs. steam injector

Post by tsph6500 »

hottshot65 wrote:How do the two stack up against each other? What are the pros and cons?
An injector is probably more efficient than a pump because it has no friction losses.

A pump is more satisfying to watch and listen to than an injector, although injectors do sing like little chirpy birds...

That's why I like to have both. :wink:
Best regards,
Jim Leggett

Montreal Live Steamers
www.montreallivesteamers.org

A Founding Member of the Tinkerbell Scale Society - Northern Division
I'm an A.R.S.E. (Association of Railroad Steam Engineers)
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tburzio
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Re: Steam water pump vs. steam injector

Post by tburzio »

hottshot65 wrote:What are the pros and cons?
Injectors get clogged, or corroded. Steam water pumps don't really pump much water. Several folks I know are going to retrofit their steamers with axle pumps, probably on the tender. Injectors in the station while stopped, axle pump when moving, and steam pump for show...

To be completely fair, axle pumps and manual pumps clog too, but you can use a hammer to get them unstuck. Thwack!
Steven E. Kuhn
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Re: Steam water pump vs. steam injector

Post by Steven E. Kuhn »

Admittedly when I first started running my Allen ten-wheeler I had an axle pump with NO bypass and I felt I needed the pump not willing to trust the injector. The axle pump was always cracked open a little. I've never had a tender hand pump nor even considered getting one thinking if it gets that bad it's time to dump the fire and start over. I've never had to do that.

I have since tore out the axle pump and have two Superscale injectors that I use. Using a filter in the tender, treating my water, and keeping the injector clean I never have any problems. I now have more steam than I need. The axle pump wasted that much energy. Typically when I run I use the injector to keep the safety valve down. But that's not always possible. (I like to sit and watch it simmer and BS with friends) The best way to do that is run your heart out and let you and your locomotive get into a rythym.

I'm glad I had the axle pump first and then took it out. It made me appreciate how running on high quality Superscale injectors is not that big of a deal and a lot of fun. Not to mention the downside to an axle pump was learned first hand.

I definitely wouldn't waste my time putting a compressor on that pumps water. Just a waste of time and energy. Put one on but my idea is to use it for locomotive and tender brakes.

I think for a beginner an axle pump is an excellent idea. So maybe put it on for a backup. It can't hurt. Then when you are more comfortable yank that puppy off and toss it.

Hope this helps,
Steve
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Harlock
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Re: Steam water pump vs. steam injector

Post by Harlock »

They sound really nice and are fun to watch, but don't have one as your primary water source. They seem to fail a lot, many different sizes and kinds on many different engines I have observed and used. Perhaps they are poorly made or badly maintained or harder to maintain, but injectors are great, just keep them clean. If they clog, do a vinegar soak and rinse. On the Chloe, mine has yet to clog - I blow compressed air through it before putting it away so it is never put away wet.

I also have a crosshead pump on the chloe which works very well, but it does sap power constantly. I think overall, the injector is more efficient than the pump. I have to use more fire when the pump is connected, regardless if it is in bypass mode or not as it is always pumping. With the injector, it only uses energy when its being used at 100%, and as someone else mentioned, less mechanical / friction loss. The only piece of high science on a steam engine.

I do use the crosshead pump since I have it as the primary water source when running, because the Chloe has so little margin, it's easier to let a little water in all the time. But for larger engines I find injector-only to be the best way to go. Have two and you're almost guaranteed not to have a show stopper on any given day.

-M
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tsph6500
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Re: Steam water pump vs. steam injector

Post by tsph6500 »

It is my experience that pumps are slightly more reliable than injectors IF both are plumbed correctly and maintained.

My 3/4" Berkshire has a Van Brocklin style duplex pump as its main water source and her boiler is 6" dia. at the smokebox (45 sq. in. grate area). I also have an injector. No axle pump. I've never used the hand pump in the tender.

The steam pump is more reliable than the injector (95% VS 80% reliable)

My Northern has a steam pump, injector and a dual axle pumps plus a hand pump under the cab.

My 10-wheeler has the same as the 4-8-4.

Lizzzy's 0-6-0 has a steam pump, single ram axle pump and a hand pump under the cab.

The unrestored 0-6-0 with a slope tender has an axle pump and an injector that LBSC built for my grandfather. Apparently Curly did this as a thank you gift for people who sent care packages to him during the War.

Mt 1-1/2" Mogul has a double axle pump, a single cylinder steam pump and an injector that needs to be replumbed to be reliable.
Best regards,
Jim Leggett

Montreal Live Steamers
www.montreallivesteamers.org

A Founding Member of the Tinkerbell Scale Society - Northern Division
I'm an A.R.S.E. (Association of Railroad Steam Engineers)
Toad Swamp & Punk Hollow Railroad - Head Tycoon
The Juvenile Traction Company - CEO & Apprentice Machinist 3rd Class
White Mountain Central RR - Engineer & Fireman
10 Wheeler Rob
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Re: Steam water pump vs. steam injector

Post by 10 Wheeler Rob »

On the subject of injectors verses stem pumps. No on has mentioned cost, in general injectors are about 1/2 the price less then a steam pump if you are a buying ready to run componet.

You can not beat the alure of waching a steam pump, slowly work.

I have 3/4" engine which came with an axle pump with a bypass and an injector. No hand pump. It was little scarry to stem the first few times untill I learned to run the injector. Runs fine when in motion with the axle pump on about 1/2 the time. The injector takes care of things just fine when stopped.

If your doing a 1 1/2" scale or larger, and plan on a battery and air compressor system for train brakes, you and consider a electric feed water pump as a backup instead of a hand pump also.

Rob
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Re: Steam water pump vs. steam injector

Post by LSGOD »

10 Wheeler Rob wrote:On the subject of injectors verses stem pumps. No on has mentioned cost, in general injectors are about 1/2 the price less then a steam pump if you are a buying ready to run componet.

You can not beat the alure of waching a steam pump, slowly work.

I have 3/4" engine which came with an axle pump with a bypass and an injector. No hand pump. It was little scarry to stem the first few times untill I learned to run the injector. Runs fine when in motion with the axle pump on about 1/2 the time. The injector takes care of things just fine when stopped.

If your doing a 1 1/2" scale or larger, and plan on a battery and air compressor system for train brakes, you and consider a electric feed water pump as a backup instead of a hand pump also.

Rob
Hand pumps, from personnel experiance, are a waste of time. Even on the smallest of 1 1/2" engines it is very hard to keep up. I have read some where that steam pumps are more efficient than injectors except exhaust injectors. I use an injector and a battery powered rv pump on my cab forward. Works fine. My son Don has an axle pump and an injector 0n his 1.593 SP GS-1 4-8-4. Works fine. A joy to run. Since I use a battery in the tender for the water pump I also use it for an air compressor for the brakes. I have a float switch in the boiler of the cab forward that indicates the water level. It turns on a red light when the water level is a little below half a guage. The switch for the pump can be turned on until the light goes out. Works great.
LSGOD
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Harlock
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Re: Steam water pump vs. steam injector

Post by Harlock »

I agree on the hand pump bit. Had to use one on a larger engine once and they don't do anything but make the engineer tired, and if you're using it, it's because nothing else is working and you'll have to do the same thing all over again not too long from then. If you're going to put in a hand pump as an emergency thing, put in an electric water pump instead. If you have three inputs and its down to a hand pump, time to call it quits for the day and go fix whatever's broken. On the Chloe we left it off. The engine will run continuously with the injector or the crosshead pump. If both break, it's time to call it quits. There's a rule in small airplane flying...if one thing is marginal, OK, but if a second thing goes wrong, the plane is trying to tell you something.

-M
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tburzio
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Re: Steam water pump vs. steam injector

Post by tburzio »

Harlock wrote:T If they clog, do a vinegar soak and rinse.
Could you elaborate on your vinegar process? Full strength vinegar? How long a soak, then what did you rinse with?
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Harlock
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Re: Steam water pump vs. steam injector

Post by Harlock »

tburzio wrote:
Harlock wrote:T If they clog, do a vinegar soak and rinse.
Could you elaborate on your vinegar process? Full strength vinegar? How long a soak, then what did you rinse with?
Tony, full strength white vinegar from the grocery store. Submerge for maybe 5 minutes max, then thoroughly rinse with running water and blow dry with shop air if you have it. You don't want any vinegar left as it will eventually eat the metal. Short exposures, it just eats the calcium deposits etc. If your brass looks a little copper-y after that, it's the vinegar separating a little of the zinc from the copper on the surface. Not harmful in the long run.

Apparently coca cola also works (like how people use it to clean toilet bowls.) but vinegar is a little more pure. :)

You can also use vinegar to do a boiler wash, though you leave it in longer depending on the amount of crud, sometimes overnight, then flush the whole system a couple of times with water. This is what my friend Jeff Badger recommends as an annual boiler wash routine.

-M
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tomc
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Re: using vinegar

Post by tomc »

You can also use vinegar to do a boiler wash, though you leave it in longer depending on the amount of crud, sometimes overnight, then flush the whole system a couple of times with water. This is what my friend Jeff Badger recommends as an annual boiler wash routine.-M
Can you expand on this? how much vinegar? Do you fill the boiler or mix as a percentage?

Tom C.
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