Diaphragm Actuator and Membrane Actuator. Is it similar? 1

[Ulon]

Dear all,

I'm seeing a document that denotes a membrane actuator. I've never know it before. Is it the other name for Diaphragm Actuator?

If it's not. I would like to get a good reference of these membrane actuator for my study?

I also welcome any comment regarding a selction of actuator for a gas service with ANSI 1500 Class. What type of actuator is suitable?

Thanks in advacne guys,


Regards

 

[roydm]

Ulon,
It sounds like a miss application of English. One of my favourites was a Japanese manual describing a dust tight enclosure talked about "Sneaky Dust"

Roy

 

[JimCasey]

A class 1500 valve might be actuated by a diaphragm actuator or it might be actuated by a piston actuator.
The selection depends on several parameters:
How much force is required?
How much air pressure is available?
How long is the stroke of the valve?

Diaphragms are good for short stroke, or low air pressure, or low force. Pistons can use higher pressure actuating fluid, can make longer strokes, and can make higher forces. Especially if they are not contaminated with "sneaky dust".

 

[itsmoked]

Gawd I just hate! sneaky dust...

Once had a bunch of metallic "sneaky dust" landing on the surfaces of a horizontally mounted powersupply with results far more destructive than your imagination would cough up.

Had 200 of them to retrofit..

Each in a rail car..

Somewhere in the United States.... <snif>

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Ulon]

thanks guys,

at least i learn new term as well.."Sneaky Dust"...i wonder if the dust over there can sneak beyond the tight closure.

 

[MangaMech]

I'm shooting from the hip on this, my sense of this is. A diaphram can be something like a top hat in geometry providing a long stroke for the diameter. The shape can basically turn itself inside out in realising a full stroke.

In contrast a membrane conveys more of a flat disk where the stroke is short, where a larger force is required or a smaller stroke.

See manufacturers found from google search.

http://www.diacom.com

http://www.warwickmills.com/Diaphragms-Fabrics.html

http://cgproducts.johnsoncontrols.com/CAT_PDF/1924050.pdf

The terms could probably be used interchangeably with no confusion.

 

[herbnovak]

Ulon,

Membrane-actuator is another name for a diaphragm-actuator.
This comes probably from the translation of a german document. In the german language the diaphragm-actuator is called "Membran-Antrieb".

For the selection of the actuator for the gas-valve you have to consider the following data:

On-off or control valve?

For on-off-application a piston actuator (double-acting or with spring-load) may be the cheaper solution.
For a control valve the diaphragm-actuator allows a smoother movement and is the better solution. The diaphragm-actuators have normally springs as a standard to provide a certain position in case of de-energizing.

In any case you have to consider as well the necessary stroke and the necessary force.
Also the rising time has to be considered, depending on the application.
For control-purposes a positioner (position-controller) is a must.

You may find additional informations for example on the Flowserve or other valve-producers web-sites.