Linear Piston Air Pump Question

[Razberry910]

I just finished my tote/pond setup this afternoon. I have a dozen totes 10 are 300 gallon 2 are 250 gallons. they are all lined up underneath a roofline the idea is rain will provide natural water changes. I plumbed in a airline loop approximately 80ft of 1 inch pvc. I have a dozen coop metal valves tapped dropping airlines about 11 feet to sponge filters. With all the tanks bubbling nicely I can hear a slight leak right where the pump meets the rubber hose I could fix this with a hose clamp or thickening the pump spout with a wrap or two of elec tape. My ball valve also leaks a small amount I didn't crank it down hard or use Teflon tape. 

That being said I installed the ball valve so I could Crack it slightly and relieve some pressure from the system. 

I can open the ball valve now where it barly hisses and the bubbles in the totes seem to stay the same. 

Question. Do I need to provide a pressure relief(crack the ball valve)to keep the pump from over working? 

 

[Fish Folk]

Wow! Awesome setup! I’d love to hear what all you plan to breed.

I do think it is safest to have some kind of pressure release. 

[Ken Burke]

I positively GREEN with envy.  

[Razberry910]

On 4/8/2022 at 7:56 PM, Fish Folk said:

Wow! Awesome setup! I’d love to hear what all you plan to breed.

I do think it is safest to have some kind of pressure release. 

Last summer we only had two totes. We made a lot of Pink Guppies and Black Bar Endlers. This summer several varieties of fancy guppies, rice fish, fancy goldfish, platies, white clouds, and a few breeds of minnows native to the US if I can find some for sale.  

[Fish Folk]

On 4/8/2022 at 8:30 PM, Razberry910 said:

Last summer we only had two totes. We made a lot of Pink Guppies and Black Bar Endlers. This summer several varieties of fancy guppies, rice fish, fancy goldfish, platies, white clouds, and a few breeds of minnows native to the US if I can find some for sale.  

I highly recommend Rainbow Shiners (Notropis Chrosomus). They are absolutely glorious fish. I breed mine on a very small scale...

 

But @WhitecloudDynasty does great with them in outdoor tubs. He can explain how to build massive populations. His shiners are gorgeous too!

Edited April 9, 2022 by Fish Folk

[Razberry910]

On 4/8/2022 at 8:37 PM, Fish Folk said:

I highly recommend Rainbow Shiners (Notropis Chrosomus). They are absolutely glorious fish. I breed mine on a very small scale...

 

But @WhitecloudDynasty does great with them in outdoor tubs. He can explain how to build massive populations. His shiners are gorgeous too!

Rainbow Shiners are on the list. They look great 

[Widgets]

Some sort of pressure relief valve is needed. I would think you would need finer control than the bsll valve would give, but maybe the airflow is large enough that it will work fine.

Think of it this way, if the pump is running continuously and is generating more air pressure than is needed to run your airlines,  the pressure will continue to increase, building up stresses on the air handling system, generating heat, and reducing the operating efficiency. You are already seeing this with the increasing pressure causing air leaks that go away when you slightly open your ball valve. The building pressure will increase the air through your airlines and into your tanks, until equilibrium is reached. You may need to reduce the airflow with the valves which will increase the pressure and find a new equilibrium.

I have often wondered if a larger system might benefit from using an air compressor with a secondary pressure valve. The compressor tank would pump up to a high pressure and shut off. The secondary pressure valve would feed the air system at a constant lower pressure. When the main tank looses enough pressure the compressor would pump it back up. Would a heavy duty high pressure pump running on a shorter duty cycle be more efficient than a lower pressure pump running continuously? 

[Razberry910]

On 4/8/2022 at 9:13 PM, Widgets said:

Some sort of pressure relief valve is needed. I would think you would need finer control than the bsll valve would give, but maybe the airflow is large enough that it will work fine.

Think of it this way, if the pump is running continuously and is generating more air pressure than is needed to run your airlines,  the pressure will continue to increase, building up stresses on the air handling system, generating heat, and reducing the operating efficiency. You are already seeing this with the increasing pressure causing air leaks that go away when you slightly open your ball valve. The building pressure will increase the air through your airlines and into your tanks, until equilibrium is reached. You may need to reduce the airflow with the valves which will increase the pressure and find a new equilibrium.

I have often wondered if a larger system might benefit from using an air compressor with a secondary pressure valve. The compressor tank would pump up to a high pressure and shut off. The secondary pressure valve would feed the air system at a constant lower pressure. When the main tank looses enough pressure the compressor would pump it back up. Would a heavy duty high pressure pump running on a shorter duty cycle be more efficient than a lower pressure pump running continuously? 

Thank you. The ball valve isn't supper fin at all but I can nudge it slightly and it's quiet when bleeding off air. I can put more of the metal valves in the pvc but they are rather loud when they are open and don't have anything connected. 

Below is the video/guy that got me concerned with the pressure to begin with.

His valve might allow for a finer adjustment and that air stone on the bottom probably muffles the sound and creates a slight back pressure.  

I could always add a second sponge filter and airline drop to each tote/pond but that seems unnecessary. 

 

[Wrencher_Scott]

On 4/9/2022 at 8:30 AM, Razberry910 said:

Thank you. The ball valve isn't supper fin at all but I can nudge it slightly and it's quiet when bleeding off air. I can put more of the metal valves in the pvc but they are rather loud when they are open and don't have anything connected. 

Below is the video/guy that got me concerned with the pressure to begin with.

His valve might allow for a finer adjustment and that air stone on the bottom probably muffles the sound and creates a slight back pressure.  

I could always add a second sponge filter and airline drop to each tote/pond but that seems unnecessary. 

 

ya, just add a valve anywhere in the line after the pump. open it until it slows the bubbles then close slightly. 

[CT_]

I actually don't think excessive pressure is a problem.  Looking at how they work they would be self limiting.  More air pressure looks more like a spring to the pump and not an additional load where the energy isn't returned on the back stroke.  This is true for diaphragm pumps too, but not ones run on dc motors like the nano pump.

 

Infact according to one manufacturer your just wasting energy.  If you're not convinced by me though it doesn't hurt to bleed off extra air pressure.

https://www.nitto-kohki.eu/en/operating-principles-en/linear-piston-pumps.html

"Anti-overpressure mechanism When the output pressure exceeds the rated value the piston stroke will automatically diminish and prevent over-pressurising. At the same time, the current and power consumption will also be automatically reduced, thus eliminating possible failure caused by tentative overload. "

 

 

[Razberry910]

On 4/9/2022 at 7:47 PM, CT_ said:

I actually don't think excessive pressure is a problem.  Looking at how they work they would be self limiting.  More air pressure looks more like a spring to the pump and not an additional load where the energy isn't returned on the back stroke.  This is true for diaphragm pumps too, but not ones run on dc motors like the nano pump.

 

Infact according to one manufacturer your just wasting energy.  If you're not convinced by me though it doesn't hurt to bleed off extra air pressure.

https://www.nitto-kohki.eu/en/operating-principles-en/linear-piston-pumps.html

"Anti-overpressure mechanism When the output pressure exceeds the rated value the piston stroke will automatically diminish and prevent over-pressurising. At the same time, the current and power consumption will also be automatically reduced, thus eliminating possible failure caused by tentative overload. "

 

 

Wow that is supper interesting!  I'd love to see two identical pump running one with say 20 tanks and one with 40 tanks. In theory the energy savings should be measurable even if it's over a months time. And would both pumps last just as long? 

[CT_]

On 4/9/2022 at 5:14 PM, Razberry910 said:

Wow that is supper interesting!  I'd love to see two identical pump running one with say 20 tanks and one with 40 tanks. In theory the energy savings should be measurable even if it's over a months time. And would both pumps last just as long? 

Yeah! I only discovered this recently when testing the coop's new battery powered pump and measuring power consumption.  The power saving principle is the same since both linear pumps and diaphragm pumps are driven (usually) by a linear motor.

 

Edit: to pump longevity I'm not sure.  Components would see more pressure.  In the case of a diaphragm pump the max pressure is so low I don't think it would matter.   For the linear pump I can think of reasons why it would actually last longer (less piston movement so less wear) with full pressure.  But also reasons it may last less long(less air flow means less cooling, but lower power means less need for cooling so🤷‍♀️)

Edited April 10, 2022 by CT_

[Razberry910]

On 4/9/2022 at 8:17 PM, CT_ said:

Yeah! I only discovered this recently when testing the coop's new battery powered pump and measuring power consumption.  The power saving principle is the same since both linear pumps and diaphragm pumps are driven (usually) by a linear motor.

 

Edit: to pump longevity I'm not sure.  Components would see more pressure.  In the case of a diaphragm pump the max pressure is so low I don't think it would matter.   For the linear pump I can think of reasons why it would actually last longer (less piston movement so less wear) with full pressure.  But also reasons it may last less long(less air flow means less cooling, but lower power means less need for cooling so🤷‍♀️)

How many years do these units normally last? Do they get loud when it's time to change the piston?

 

[Widgets]

On 4/9/2022 at 7:47 PM, CT_ said:

I actually don't think excessive pressure is a problem.  Looking at how they work they would be self limiting.  More air pressure looks more like a spring to the pump and not an additional load where the energy isn't returned on the back stroke.  This is true for diaphragm pumps too, but not ones run on dc motors like the nano pump.

 

Infact according to one manufacturer your just wasting energy.  If you're not convinced by me though it doesn't hurt to bleed off extra air pressure.

https://www.nitto-kohki.eu/en/operating-principles-en/linear-piston-pumps.html

"Anti-overpressure mechanism When the output pressure exceeds the rated value the piston stroke will automatically diminish and prevent over-pressurising. At the same time, the current and power consumption will also be automatically reduced, thus eliminating possible failure caused by tentative overload. "

Yes, a magnetically driven piston is self limiting. The old piston pump that I had years ago (and gave away when I got out of the hobby) was driven by a shaft that always went full stroke. Running without a pressure relief valve would reduce the life of the leather gaskets on the pistons. I wish I still had that pump.