Adjustable flow, need a bleed valve?

[ramzilla]

If an air pump has adjustable flow, do you still need to add
a bleed off valve to help with longevity of pump?
Didn't know if the adjustable flow, was basically doing same thing.
thx

 

[KingOscar]

I don't believe the flow adjustment knobs bleed air. I think they change the amount of vibration. (Edit: I'm not certain on this, seeking clarification from someone who knows)

Bleeding air prevents diaphragm damage if the system has a lot of back pressure, like when it becomes restricted with clogged air stones. Forcing a powerful pump to run through only 1 or 2 air stones will also cause back pressure.

Imagine a pump that could easily power 12 air stones being forced to push all that flow through one. That's restriction and is hard on the pump.

As long as you are using a proper size pump and maintaining the system, you really only need to bleed air when you desire to reduce the flow.

 

[ramzilla]

That makes sense.
It is just powering two sponge filters, so I had assumed that they
didn't have much restriction to begin with.
Just wanting to be sure that I'm being mindful of equipment.

 

[KingOscar]

I don't believe the flow adjustment knobs bleed air. I think they change the amount of vibration. (Edit: I'm not certain on this, seeking clarification from someone who knows)

I checked a Whisper 650 pump I had at home that has an adjustable output dial. It operates electrically through a rheostat or potentiometer to alter the output... it does not bleed air. I suspect newer pumps operate in the same manner.

I believe leaving it on high and using gang valves to bleed air when necessary to be the wisest choice for both output and longevity.

 

[ramzilla]

gotcha, thanks for input!!