Diaphragm actuator

[Valving]

Could someone advice the advantages of multi spring diaphragm actuator vs.
single spring diaphragm actuator or piston actuator?
Or the reason to use it?

 

[danw2]

Multispring actuators can be re-configured (reassembled) in the field to operate in the "Air to open" function or with the reverse action "Air to close".

 

[gerhardl]

The answer has to be very general. The only way to get an exact answer is to have a single, exactly defined situation (fluid, flow, pressure, pressure difference, temperature, surroundings, pipeline layout, operational mode and sequences etc. etc) and two competitive actuators/valves, one of each kind, exactly described.

The general answer is as danw2 has described.

In addition to reversing the 'normal' state (open vs. closed) several springs (equal or different, one inside the other or 'parallell') gives a higher number of possibillities to regulate the force and speed of opening/closing movement, or balancing (dampening)regulation force (if regulation valve) than a single spring actuator. Several springs will also give a possibillity to build the actuating devices smaller, and might give a more centered and paralleld movement in some cases.

 

[Valving]

Thanks it is raw water application, line size 20inch, valve ended up 12 in sizing.
max upstream pressure is 5.6 bar and delta p is 0.1 bar.
Straight globe valve is used.

What I understand is there is no specific application that forces to have multi spring type
but it is more for preference from operation point of view.

 

[gerhardl]

I presume this is the normal situation without much variation. In this case it is a fairly simple application and a 'standard' valve and actuator could well be used.

Upgrading quality in this case would be looking into valve-constructions (and actuators) that could give a lower
cost/lifetime. That could mean a higher quality and higher buying cost, but lower maintenance cost and longer standtime/lifetime.

To mention only one problem (world-wide): valves of too low quality remaining in one position in years, failing to close, open or thightening properly when finally operated. ( Higher quality and/or regular operation tests should hae been done)