Hydraulic cylinder pneumatically operated

[MedicineEng]

Dear All:
I am studying an application to lift up an equipment with approximate weight of 650Kg. The problem is that due to space constraint, I cannot use a lifting platform to do it. As such I would like to lift it like a hoist, with a hook.
The main issue here is that equipment is working in a Ex-proof zone and all electric hoists that I saw were too bulky for use.
I remember that long time ago I saw an application of a hydraulic cilinder pneumatically operated that was in use in a pallet truck, also in a Ex-proof zone. This was working in a opposite way that since I intend to lift the equipment from above.
Does anybody knows about any application like this?

Thanks a lot for your help.

 

[Montemayor]

Paulo:

I think you'll find that hydraulic cylinders are used with hydraulic (usually oil) pumping systems. Pneumatic cylinders (like the one you seem to describe) operate using compressed air. A pallet truck usually has a hydraulic cylinder, since motorized equipment carry the ability to hook on an oil pump - as opposed to an air compressor.

I've used both types of cylinders in plant applications and I find the hydraulic type to be stouter, tougher, and more reliable that the pneumatic variety. You can buy hydraulic motors (as well as pneumatic one) for the application you describe. Look in Google or in an industrial tools catalog and you should easily find hydraulic hoists for 1 ton lifts.


Art Montemayor
Spring, TX

 

[Michael996]

Generally, hydraulic cylinders are not designed to have air-tight seals. You would have to do some checking on the seal design if you are planning a 'mis-application' of the component.

 

[EdDanzer]

Hydraulic cylinders may not work as well as a pneumatic cylinder for you job and should cost more. There are several pneumatic hoist manufactures that use air motors to drive the chain or cable hoist for explosion proof applications.

 

[nbucska]

Is the lifting device supposed to be permanently installed
or only occasionally e.g. for repair?

<nbucska@pcperipherals DOT com> subj: eng-tips

 

[MedicineEng]

Dear nbucksa:
The equipment should be permanent installed since it is needed for daily operation.

Thanks


PR