Axle pump feed water

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hoppercar
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Joined: Sun Jul 22, 2018 4:09 pm

Axle pump feed water

Post by hoppercar »

I wish now, I would have put another check valve up on the boiler, for the axle pump...but oh well.....right around the corner from the blow downs, I have washout plugs on the throat sheet...was planning on running the pump into there, putting water in down low near the mud ring....has anyone else done this on the rrsc mikado ?
Berkman
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Re: Axle pump feed water

Post by Berkman »

Not to open this can of worms, but two injectors on a RRSC mike is plenty.
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cbrew
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Re: Axle pump feed water

Post by cbrew »

I would not put cold water anywhere near the mud ring. is this a copper or steel boiler?
If it is not live steam. its not worth it.
FLtenwheeler
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Re: Axle pump feed water

Post by FLtenwheeler »

I go into the front flue sheet at the same level as the other check valves for my axle pump on my Allen 10-wheeler.

I like the axle pump. It keeps the water level mid glass 99% of the time.

I use my engine to train people on how to run a steam locomotive. One less thing for me to worry about.

I use a rubber cup on the pump plunger with a hard nylon backup ring. It has been working since 1985.

Tim
He who dies with the most unfinished projects: Should of put more time into their hobby.
hoppercar
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Re: Axle pump feed water

Post by hoppercar »

I think your right..2 injectors is plenty.....this my first go around with an axle pump after building several engines. It's a hastle too get to too plumb up, let alone if it starts leaking, and your on your back under the steaming bay tinkering with it...I think I am going to take the eccentric straps off for now, so it won't move...and see how my first season goes with just the two superscale economy injectors.....can always plumb it up later if needed. ... ..my same thought process applies to hand pumps on these larger engines. ..to move enough water to take care of a rrsc mike boiler, you would need a large hand pump, with a bowling ball on the handle to move it....just doesn't seem practical
Pontiacguy1
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Re: Axle pump feed water

Post by Pontiacguy1 »

I like an axle pump, but they do have their drawbacks, such as accessibility, and they are a wear item. More ways to put water in is better in my opinion, But I do know of a few people who have put them on and then taken them back off after a few years. You're right that a hand pump on anything bigger than a small mogul or American in 1 1/2" scale seems quite useless to me. In the smaller scales I can definitely see the usefulness. I've had people tell me that they liked having one so that if all else failed, they could always hand-pump enough water into the boiler to get it back to the steaming bays. Sort of like an insurance policy.

Why can't you just drill and tap another pipe thread for another check valve into the side of your boiler? I always build in an extra one or two in the boilers I make. You don't have to use them, but if you ever decide to add that twin-cylinder steam pump, then the place for the check valve is right there handy.
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NP317
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Re: Axle pump feed water

Post by NP317 »

I'm with Pontiacguy1:
Make a new NPT input in the side of the boiler, near an existing check valve input.
Putting cold water in near the mud ring can be a thermal stress-producer. Not recommended.

Axle pumps?
My Ten Wheeler has one which has worked perfectly for 15 years, surprisingly without maintenance! (...now it will need servicing...)
I plumbed the tender hand pump through the axle pump, so it gets primed any time I use the hand pump.
I test the hand pump as part of every steaming session: before heading out onto the tracks. Standard safety procedure.
I installed a similar axle pump & plumbing on my 90-ton Mikado. So far it also works fine.

Tender hand pump?
OK for emergencies and axle pump priming, but best used for performing hydrostatic pressure tests.

My thoughts.
~RN
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Fender
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Re: Axle pump feed water

Post by Fender »

The best (or maybe “least bad”) way to put cold water into a boiler would be to spray it into the steam space at the top of the boiler. This way, the steam will heat the water and drive most of the oxygen out of the makeup water before it mixes in. Alternatively, you could feed it into a copper tube running inside the boiler, so the water is heated somewhat before it mixes in. Cold water is more dense than hot water, so the tendency is for it to seek the lowest level, which is usually the mud ring.
Dan Watson
Chattanooga, TN
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Bill Shields
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Re: Axle pump feed water

Post by Bill Shields »

or do what PRR did and mount feed in from the backhead into an open-ended pipe that runs up toward the front tube sheet.

As for driving the oxygen out before it mixes in...that's really only a problem for you ferrous kettle folks.....giggle

as for pumps...you can NEVER HAVE too many.
Too many things going on to bother listing them.
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Greg_Lewis
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Re: Axle pump feed water

Post by Greg_Lewis »

Bill Shields wrote: Fri Mar 08, 2019 9:36 pm or do what PRR did and mount feed in from the backhead into an open-ended pipe that runs up toward the front tube sheet.

...
That's what the late Cal Tinkham did on his 10-wheeler. You just set the axle pump and forget it. That boiler could generate enough steam for two locomotives.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
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ChipsAhoy
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Re: Axle pump feed water

Post by ChipsAhoy »

I've been allowed to take my friends Mogul out many times, and have had to push her back in twice, because I have caused his superscale injector to become erratic and I can't get repair parts for it. Were it not for the axle pump, I would never have gotten out the chute. The tender hand pump.... only good it is for is to pull the handle out, and flog yourself in the face with it. IMHO.
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Fender
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Re: Axle pump feed water

Post by Fender »

Usually, the problem with erratic injectors is caused by trash getting into the cones. Do the injector(s) have strainers on the feed lines from the tender? I had the same type of problem, but installing strainers completely eliminated it (until the strainer fills up 🙄). I clean the strainers every few runs.
Dan Watson
Chattanooga, TN
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