request for info

thanks for the effort, but the link gives me more info about hydraulic aand pneumatic actuators, what i am lookin for is diaphragm actuators, n i have searched thomasnet, global spec.. dint get much info what i needed.. thanks anyways..

If the pressure is limited you can use hydraulics with pneumatic membranes if the materials are compatible. Look at the belofram membranes.

In general you do not find hydraulic membrane actuators because hydraulics are always related to higher pressures and membranes for high pressure do not exist.

If you want to avoid friction it is possible to use bellows at evn rather high pressures.

Yes. Contact harry.hogg@helical-technology.co.uk who is Sales Manager for this Company which makes Diaphragm Actuators.

thank you very much for the link.. i contacted them.. waiting for a positive reply..

http://www.lesliecontrols.com/Products/actuators_posit.htm

They show an electric actuator, Which, if I'm not mistaken, is hydraulic. When I worked there (1988-2000), I evaluated linear and rotary electrically driven hydraulic actuators from Rexa. Apparently they are still using those items.

An electronics engineer and I developed the DPS and PMC electro-pneumatic system. Unless you need hydraulic stiffness and power, the electro-pneumatic systems can work up to 100 PSI and are surprisingly fast (I pushed for that). They are even available intrinsically safe (60 PSI) for explosive atmospheres.

I outfitted a PMC system for myself in 1996 to fill tires to +/- 0.1 PSI. Wanted to target Nascar but marketing didn't understand the impact it would have had. Only within the last few years has Nascar been adjusting pressures to that accuracy.