water cyliders
water cyliders
(OP)
I'm searching hydraulic cylinders to work with water. This last point is the most important one for my customer. They are going to work only in traction movement, and the force is low because they are going to be used to lift a weight of 300 kg. The total movement lenght is 1500mm. Does anyone know who could manufacture this kind of cylinders?





RE: water cyliders
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The Danfoss one might help you....talk to their reps and see what they think
Kevin Hammond
Mechanical Design Engineer
Derbyshire, UK
RE: water cyliders
The principal problem is that the use of water is required by my costumer, I know the dificulties but the system is going to work very slow and the pressure is going to be lower while moving so I'm principallly worried because of corrosion and lubrication. Perhaps it could be possible to have treated water because I'm going to have a closed system.
Javier Castillo
Industrial Engineer
RE: water cyliders
I would think that with the correct material choice (if pressures and loads are low enough then maybe some sort of polymer may be a possibility) would be your best solution for the issue of corrosion. As I said earlier find a rep that is interested and see what you can get them to do for you.
I think it would be well worth posting this one on the Fluid Power Professionals forum as well, see if any of them have something to add.
Best of luck with the project
Kevin Hammond
Mechanical Design Engineer
Derbyshire, UK
RE: water cyliders
Following points:
Water to be normal drinking/freshwater having passed a normal drinking water treatment plant.
Water must in addition be supplied over a fine (household) water filter (microsize), selfcleaning - handoperated or automated, directly in front or nearest possibel the cylinder.
Cylinder must be operated regularily to change the water. Cooler climate and water at least once a month, for warmer perhaps at least once a week or once each 48 hours?
Cylinder ought perhaps to be inspected after a trial periode to check for chalk or mineral deposits. (You actually will not know possibly negative chemical raections before you actually try, this could occur in some few cases, one per cent or less ?)
The customer must accept a possibel shortened lifetime.
We have had cylinders working trouble free for many years running, a few others from certain areas/locations that unexplained gives trouble -(could be false operating, poor filtering).
Soft sealings for cylinder to be supplied with cylinder, extra cylinder complete if critical.
Cylinder shaft to be equipped with scraper/sealing if available.
Hand operated or special solenoid valve for water to operate the cylinder (special types suitable)
Water is a non-compressibel medium and at low/normal pressure will need time to fill a cylinder through relatively small borings. Beware of necessary operating time! (Can be rougly calculated giving boring size and guessing at a sensible water speed)
Allow cylinder area to compensate for possibly lower water pressure than stated.
Cylinder material: quality grade aluminium could be used, but stainless steel recomended.
And last: why water operation to complicate things, air or electrical would be better?! What's wrong about a standard lifting table electrohydraulic or electric from floor up, or electric hoisting device from ceiling down. Even a oil-hydraulic cylinder with a smaller separate aggregate would probably have lower lifetime cost!
Main use in my area : To operate gate valves, mainly DN300 up to DN500 where water pipes are present, and electric not present, too complicated or costly. Cylinder material: aluminium, allowed for water by the cylinder fabricator.
RE: water cyliders
Cheers
Kevin Hammond
Mechanical Design Engineer
Derbyshire, UK
RE: water cyliders
I've tried sourcing stainless hydraulic cylinders here in the US, there are a number of manufacturers. Most of the devices I found were over-built for the pressures we intended to run (below 150 psi). In the end, we found it to be cheaper to manufacture our own cylinders, using drawn stainless tubing, epdm seals, and custom-made end caps. An "easy" end cap is to simply punch holes thru the thin-wall shell tube, drive a socket-head screw thru the wall into the end cap, and let the head of the socket-head screw protrude and retain the cap. We had good luck in hydrotests of prototypes using this method.
Then, we ended up going to a diaphragm cylinder, also a custom-made solution, for leakage reasons that have little to do with a typical hydraulic application.
RE: water cyliders
Thanks all for your opinions and indications. I have found, as recommended by btrueblood, who could manufacture my own cylinders with the indications given by all of you.
RE: water cyliders