hydrolic power

Theoretically...yes...

But it depends very much on the application. Are the components and application suitable for use with water?

If you were building a hydraulically operated machine to work in a river then it would be very sensible to use the river water.

If you want to convert your car's braking system to use water it is a bad idea!

Water exposed to the atmosphere always has some air dissolved in it. When put in a closed system, it can come out of solution and the reliability will degrade (try using brakes that have not been "bled" properly!).

Wetted iron or steel parts (to name a few) will be subject to corrosion.

Mike

There are plenty of very old water pumping stations and hydraulic machines on the canal system in the UK. I always assumed they used cast iron...

Dunno why it doesn't rust up? Anyone out there know this stuff..

Curiosity killed the cat? :(

Cast iron is used for fittings found in compression, like the chairs and baseplates to be found on timber-sleeper railway track. Though exposed to the elements, that corrosion which takes place to cast iron only occurs on the surface and the component will last and retain its design strength well unless subjected to local corrosive atmospheres. A heritage railway 35km from here in a rural district with 635mm of annual rainfall has cast-iron components in a passenger running line with a cast date of 1902 and in sidings dated 1874, all still in use, and all unpainted.

Steels in rails, in comparison, have a different carbon content and though their renewal due to corrosion loss does happen, the driver for renewal is more likely surface wear and the desire to standardise the sleeper system to something more durable than timber where developments for higher speed are taking place.

The cast iron baseplate has been largely superseded on the UK national network with the proliferation of the pre-stressed monoblock concrete sleeper and the change in the availability/quality/price relationship of timber. Another driver has been the systematic elimination of the timber sleeper, which has been the shortest-lived component and the item requiring most renewal activity. Despite this, cast iron can still be found here widely, and is occasionally installed from recovered or new components where timber sleepers prevail, particularly in the assembly of junctions. Though concrete bearers are available for some standard designs of modern junction, cast iron on timber is more suited in many instances.

A suitable testament to the durability of cast iron correctly used and protected might be the iron bridge over the River Severn, at Ironbridge, widely believed to be at the centre of the cradle of the phenomenon known as the Industrial Revolution.

Three cheers for cast iron. Hip-hip.....

Hooray, cheers.

So I can reasonably assume cast iron bores in those big horizontal beam engines.

Del

I know of large Injection Presses that use water with Ethylene Glycol mix.

Here are two companies that make hydraulic equipment that runs on Tap Water:

http://www.elwoodcorp.com/fluid.htm#cartridge

http://www.huntvalve.com/index.htm

Hydraulics is the use of a fluid with its mechanical properties. Water can be used for most application oil is used. The use of water will incur bad results over time and be more costly to maintain. Lower viscosity will need tighter seals, closer tolerances on the pump. Steel rust will need to up grade to SS. Will not be as efficient. Most water pumps are not designed for the pressures that the market produces for oil.

Yes it can be done. But why?

oxxb wrote;

"Yes it can be done. But why?"

Fire Resistance such as in molten metal industries for one

Contamination such as over or on water ways for one.

Water in molten metal wouldn't want to be there. If used in a closed system can get pretty nasty.

On a different note, Where do you think the word "Hydraulic" came from?

Notice it starts with "Hydra" which is the start of many words that have to do with Water or its control. The original Hydraulic systems used water as their fluid. Oil and other fluids such as Ethlyene Glycol/Wate mixture, 95/5, 95% Water 5% Soluble oil are prevalet today in most systems around heat sources that might start mineral oil burning.

I agree, Water In Molten Metal is a disaster, however, water on molten metal is not a problem.

Further to previous comments, water is used worldwide in jetting applications for cleaning, fire fighting and in UHP (ultra High pressure) for cutting steel etc.etc.

I have used triplex piston pumps for 25 years in flushing systems, although usually for fluids with a glycol mix for the oil industry. These are specifically designed for pumping water.

As already stated, the earliest hydraulic systems used water. Seals were made of leather so the pressures were relatively low. There are several manufacturers of e.g. Air driven hydro pumps that will pump water to 100,000 psi.