Pumping Air thru Water Pipe

[carlyai]

I'm going to pump air thru 20mm PVC 13.5 water pipe to my fish tanks. I'll be using some manual open/shut valves. Will the air leak thru or out of the valves? 

In other words, do the valves leak air?

[BritManToo]

If they leaked air, they'd leak water.

[carlyai]

10 minutes ago, BritManToo said:

If they leaked air, they'd leak water.

Thanks, that's what I thought.

[Dumbastheycome]

The only problem  you might have is in the longer term if you are using the  PVC shut off  valves and opening  closing regularly because the rubber seal around the  neck of the valve handle would normally be "lubricated" by water. Operating them dry might eventually create air leaks.

[sanmyintmaung]

You may need a safety release valve in case of pressure build up. If you accidentally shut off manual valve while air pump is running, you will have compressed air inside the PVC pipe. Water is not compressible and cannot store energy in the same way that air can. When air is compressed inside of PVC piping, the pipe can swell and burst at a high pressure, sending PVC shrapnel outward, potentially injuring anyone within close range.

[carlyai]

19 minutes ago, Dumbastheycome said:

The only problem  you might have is in the longer term if you are using the  PVC shut off  valves and opening  closing regularly because the rubber seal around the  neck of the valve handle would normally be "lubricated" by water. Operating them dry might eventually create air leaks.

Yes good thought. I won't be using them, just a precaution. Thanks.

[sometimewoodworker]

1 hour ago, carlyai said:

I'm going to pump air thru 20mm PVC 13.5 water pipe to my fish tanks. I'll be using some manual open/shut valves. Will the air leak thru or out of the valves? 

In other words, do the valves leak air?

If you use PP-R then the valves are better and it doesn’t get brittle with age allowing a shrapnel like burst.

[Artisi]

What is the maximum pressure your air pump achieve? 

[carlyai]

1 hour ago, sometimewoodworker said:

If you use PP-R then the valves are better and it doesn’t get brittle with age allowing a shrapnel like burst.

Thanks. Just found this image of how I was going to connect the pump to the air feed. The air pump connects thru a black connector to the top PVP pipe, then fed via 4 switches to 4 20 mm pipes to the fish tanks.

[carlyai]

1 hour ago, Artisi said:

What is the maximum pressure your air pump achieve? 

Hi. I have 2 1000L water tanks and I calculated (long ago) I need 35/45 LPM to each tank (depending on fish stocking density). So I thought 1 air pump around 90 LPM.

 Lazada has Ataman HP-12000 @ 110 LPM and specs say 0.032/0.44 Max. MPa. 

[Artisi]

1 hour ago, carlyai said:

Hi. I have 2 1000L water tanks and I calculated (long ago) I need 35/45 LPM to each tank (depending on fish stocking density). So I thought 1 air pump around 90 LPM.

 Lazada has Ataman HP-12000 @ 110 LPM and specs say 0.032/0.44 Max. MPa. 

Max pressure is therefore approx. 66 psi, sufficient to cause damage and injury if something was rupture/fail if the pipework / fittings can be at max pressure, you need either a pressure relief valve or arrange the system so as it cannot be completely pressurised, ie, have an open bypass somewhere in the system that cannot be closed off. 

[carlyai]

33 minutes ago, Artisi said:

Max pressure is therefore approx. 66 psi, sufficient to cause damage and injury if something was rupture/fail if the pipework / fittings can be at max pressure, you need either a pressure relief valve or arrange the system so as it cannot be completely pressurised, ie, have an open bypass somewhere in the system that cannot be closed off. 

Thanks. So a safety relief valve would be good. I was only going to use PVC 8.5 pipe because I have some left over, but it would be better to use PVC 13.5 and a safety relief valve. I'll Google the safety relief valve. What value relief valve would you suggest? Above 66 PSI?

The air pumps to 4 separate pipes that feed 2 air tank inlets per fish tank. Probably going to say something stupid here, but does that mean the pressure per pipe is about 16 PSI?

From this pic you can just see the white fiberglass female connector, in the water tank sump, that the air pipe connects to. 2 connections per sump.

 

[Artisi]

36 minutes ago, carlyai said:

Thanks. So a safety relief valve would be good. I was only going to use PVC 8.5 pipe because I have some left over, but it would be better to use PVC 13.5 and a safety relief valve. I'll Google the safety relief valve. What value relief valve would you suggest? Above 66 PSI?

The air pumps to 4 separate pipes that feed 2 air tank inlets per fish tank. Probably going to say something stupid here, but does that mean the pressure per pipe is about 16 PSI?

From this pic you can just see the white fiberglass female connector, in the water tank sump, that the air pipe connects to. 2 connections per sump.

 

The pressure that ever it is will be the same in each pipe. 

[carlyai]

19 hours ago, sometimewoodworker said:

If you use PP-R then the valves are better and it doesn’t get brittle with age allowing a shrapnel like burst.

Thanks again @sometimewoodworker

I will revisit this and see if I can switch to these fittings. Seems like using PVC Pipe is the wrong way to go. 

[maxpower]

On 8/6/2020 at 11:58 AM, carlyai said:

Lazada has Ataman HP-12000 @ 110 LPM and specs say 0.032/0.44 Max. MPa. 

I was interested to know why a fish tank air pump would be making 60+ psi.

Maybe my results are incorrect.

 

 

[Artisi]

5 hours ago, maxpower said:

I was interested to know why a fish tank air pump would be making 60+ psi.

Maybe my results are incorrect.

 

 

Think the pressure is just what the pump can supply, nothing to do with what is required, hence the need for pressure relief of some sort. 

[maxpower]

33 minutes ago, Artisi said:

Think the pressure is just what the pump can supply, nothing to do with what is required, hence the need for pressure relief of some sort. 

I agree but its only 6.3 psi max not 63 psi which is less of a worry if using PVC pipe and maybe no need for a relief valve. Just a thought as pumps and pipes are not my field.

 

[Damrongsak]

Seems pretty tame to me.

 

 

[Artisi]

12 hours ago, maxpower said:

I agree but its only 6.3 psi max not 63 psi which is less of a worry if using PVC pipe and maybe no need for a relief valve. Just a thought as pumps and pipes are not my field.

 

You are correct, the OP advised 0.44 Mpa originally. 

[carlyai]

1 hour ago, Artisi said:

You are correct, the OP advised 0.44 Mpa originally. 

Yes, very sorry. Can't find that reference now but I probably forgot a 0. Probably should have been .033 -.044. 

Thanks for the help. I can always rely on this site to set me straight.

While I had the PP-R pipe and some fittings, I needed some more fittings, so had an enjoyable 200 km round trip to Mukdahan to pick up the other bits, a box of red and a lovely lunch with wifey. So the construction is all in PP-R now, not PVC. 

[Artisi]

30 minutes ago, carlyai said:

Yes, very sorry. Can't find that reference now but I probably forgot a 0. Probably should have been .033 -.044. 

Thanks for the help. I can always rely on this site to set me straight.

While I had the PP-R pipe and some fittings, I needed some more fittings, so had an enjoyable 200 km round trip to Mukdahan to pick up the other bits, a box of red and a lovely lunch with wifey. So the construction is all in PP-R now, not PVC. 

No problems, the lunch plus a box of reds sounds pretty good. 

[Beardog]

ABS may suit your need better. You can get fittings that seal leaks & it isn't that much more to go all out. We switched to ABS for our sprinkler setup for 5 rai & it was a joy not having to tend leaks all the time. The fittings are   just much better than the PVC that they slam out that never really seems to fit anything. ABS is made to better specs & available at sprinkler shops & the like.