Marsh Simplex Waterside blues

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dhic001
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Re: Marsh Simplex Waterside blues

Post by dhic001 » Sat Jan 23, 2016 9:28 am

I suspect that it is largely due to the piston that you have a problem. I would change it to leather cups if you can, hopefully it is a standard size. If the pump is flooded suction, you don't need a check valve on the suction, if you are lifting, then the check valve needs to be a at the lowest point of the suction.
The only things it can be are valves, piston or gland packing (unless the gaskets are leaking between the chambers).
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Re: Marsh Simplex Waterside blues

Post by fredrosse » Sat Jan 23, 2016 5:00 pm

"The shuttle valve arrangement is quite unique and very interesting."

Yes it is indeed. Looks like the shuttle pistons on the valve axis get their steam from the space between the two main steam pistons. A clever way to assure reliable function of the shuttle valve (the most common trouble with shuttle valve arrangements), with steam pressure in a storage reservoir (the space between the two main pistons). Steam pressure is fed by leakage past the main rings, possibly small drilled passages in the main pistons, or best arrangement, with small ball checks in the main pistons allowing pressurization of this space whenever steam pressure is on either of the main cylinder ends. While not the best arrangement for steam economy, that is usually not such an issue with this type of pump.

That is all a guess on my part, so please if anyone knows differently tell me I'm all wet.
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Re: Marsh Simplex Waterside blues

Post by DetroiTug » Sat Jan 23, 2016 7:23 pm

On the Southworth there are essentially two slide valves, the primary or pilot simply get knocked back and forth by an arm off of the pumpshaft. That controls a double ended shuttle that controls the slide valve for steam admission in to the cylinder. Kinda clackity but it works. I left the shuttle a solid 5/8" diameter bar on each end, with it's heavier mass it's noisy. Going to remove it before next spring and hollow it out to lighten it and insert a rubber bumper on the end to deaden the impact. It mounted on a steel hull, it's pretty noisy, get the clunk down to a click. Not to take anything away from the Southworth, it's a great pump and I'd build another if needed. Once I got the O-ring issue sorted, it's ran trouble free since.

There is an interesting pump designed by Bill Durham in SB&MSL (around 1/3rd way in if I remember correctly) that looked very compact and clever. Took me some time studying the picture to figure out how it works.

Ron F, that would be good article to print for the magazine if they allow it.

-Ron
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Re: Marsh Simplex Waterside blues

Post by cyberbadger » Sun Jan 24, 2016 5:51 am

Ugh. Always something.

Well the leather rings seal, but too well. They are so snug that under compressed air the steam side stalls. :/

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-CB
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Re: Marsh Simplex Waterside blues

Post by TahoeSteam » Sun Jan 24, 2016 6:25 pm

cyberbadger wrote:
Image


-CB
Looks like one of the piston rings on the steam side was replaced at one time, seeing as one is step cut and the other is a butt cut ring.

Leather will swell once its wet... cutting it to the same diameter as the bronze portion, or even slightly less will most likely be plenty.
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Re: Marsh Simplex Waterside blues

Post by cyberbadger » Wed Jan 27, 2016 4:54 am

Got some proper leather cups from lehmans and turned simple spacers to hold the cups and hug the shaft.
https://www.lehmans.com/p-3089-replacem ... x?show=all

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Then I just need to adjust the spacing with some washers.

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Will try it soon.

-CB
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Re: Marsh Simplex Waterside blues

Post by cyberbadger » Fri Jan 29, 2016 4:30 am

Well I got it to pump water into a bucket. The leather cups from lemans worked in a new arrangement.

It's still so damned finicky. The shuttle valve on the steam side was acting up a little today.

But it's close enough to working that I am going to test it under steam for the first time ever for me (Within the next week or so) because they dynamics will be different under steam and I've gone as far as I can with compressed air.
Akitene wrote:Any chance to get a photo of the steam chest (unbolted)?
Akitene - Here are some pictures you asked for - red arrows point to pins? -- These do not go anywhere - you can't blow through them...
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Final arrangement of water side piston.
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-CB
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Akitene
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Re: Marsh Simplex Waterside blues

Post by Akitene » Fri Jan 29, 2016 6:59 pm

Thanks for the photo, CB. Very interesting but disappointing too 'cause I still can't figure how it works.

I'm wondering what the 2 pockets (pointed by red arrows) are meant for?

Image

By the way, this pump is really lovely and you're doing a great job.
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Re: Marsh Simplex Waterside blues

Post by DetroiTug » Fri Jan 29, 2016 10:59 pm

Quote: "I still can't figure how it works."

Pay attention to the three very small journals represented by dotted lines in the drawing.

The center one is to supply steam between the pistons - it stays pressurized all the time. When the two piston move one direction the lead piston goes beyond one of the outer journals and supplies steam up to the shuttle piston on that side - it in turn moves across and takes the main steam cylinder slide valve with it which reverses the direction of the main steam pistons. It stays in that position until the main steam pistons travel all the way back across. Then uncovers the other outboard journal - sends steam up to the other end of the shuttle and sends it back to start all over.

I really like that design. Looks like it would be a bugger to get cast up.

The rods on the end of the shuttle protruding out the ends are for when the shuttle sticks on scale from the boiler, the engineer can help it along until it clears.

-Ron
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Akitene
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Re: Marsh Simplex Waterside blues

Post by Akitene » Sun Jan 31, 2016 7:32 pm

It's perfectly clear. Thanks, Ron.
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