Air in the system

[Sandro Baptista]

Hi Guys,

I hope you can clarify me about the following:
Several times I heard to say that if a needle of the gauge is instable it could mean air or the system...Why is that? If it's that true I think not every time that happens it means that is air, right?

[Sandro Baptista]

PLease don't forget of me...

[ktm]

No not the only reason for your guage fluttering. U sure your guage is not faulty?

[Sandro Baptista]

I haven't any gauge with problems. Just want understand what's the reason why the air influence the fluttering...what have so especial comparing with the refrigerant fluids in vapour state?

[nike123]

Hi Guys,

I hope you can clarify me about the following:
Several times I heard to say that if a needle of the gauge is instable it could mean air or the system...

I would say rubbish!

[mikeref]

Air in the system? If its the high pressure gauge i'd say the discharge service port is open too much but air contamination will cause that needle to wind over somewhat!

[Old cooler]

Hi do you mean the discharge or suction guage?

1: Is it slowly moving up and down.?
2: Or is it moving fast?

Look forward to seeing your reply

Steve

[NoNickName]

No, it's plain rubbish. That is only true in a water system, when bubbles flow. In a refrigeration circuit, air just stands in the highest point, that is the generally the condenser manifold of top half of the coil.

[chemi-cool]

Air in a system will cause the high pressure to rise very high.
If you have air in the system you will have to change the refrigerant, drier and compressor oil.

When the niddle in the discharge gauge is instable > very instable, it tells you something of the condition of the valves and piston rings.

Rubbish in the system is totally a different story.....:D

[NoNickName]

Hope he doesn't have rubbish in the system.

[Sandro Baptista]

Air in the system? If its the high pressure gauge i'd say the discharge service port is open too much but air contamination will cause that needle to wind over somewhat!

Why? Please give me a physics explanation.


Hi do you mean the discharge or suction guage?

1: Is it slowly moving up and down.?
2: Or is it moving fast?

Look forward to seeing your reply

Steve

No problem with any gauges. It's just sometimes I heard talk about the instability of the gauges associated to the presence of the air.




No, it's plain rubbish. That is only true in a water system, when bubbles flow. In a refrigeration circuit, air just stands in the highest point, that is the generally the condenser manifold of top half of the coil.

Yes, I also agree.

[dane mccarthy]

This would be the discharge port is open to much which causes the gauge to flutter, if air is in the system it will sit in your condenser i dont belive air would cause your gauge to flutter, your head pressure would be very hight but if you had air in the system.

if a water system has air in it the gauges will move all over the place but it will sit in the highest point which there should be auto bleads at this point.

[shieldcracker]

My first post...

If your gauges are fluttering I would suspect that you need to get new ones or at least ones that have liquid damping. Otherwise you have a reciprocating compressor which has either no attenuator or an improper sized one. Try measuring the pressure as far away from the compressor.

The fluttering is proportional to the number of pistons, rpm, compression ratio

[Sandro Baptista]

My first post...

If your gauges are fluttering I would suspect that you need to get new ones or at least ones that have liquid damping. Otherwise you have a reciprocating compressor which has either no attenuator or an improper sized one. Try measuring the pressure as far away from the compressor.

The fluttering is proportional to the number of pistons, rpm, compression ratio

"...have liquid damping."

Yes typical they are fill with glycerin. However at this moment no problem I have with gauges. Read my first post. thanks.



"Otherwise you have a reciprocating compressor which has either no attenuator or an improper sized one."

An oil separator will help a lot.


"The fluttering is proportional to the number of pistons, rpm, compression ratio"

Not necessary proportional to the number of pistons. Depending of the conception of the crankshaft more pistons could give less pulsations.


Thanks Shieldcracker

[razor007]

As chemicool said the guage needle moving up and down rapidly on the high side would indicate that the compressor valves or piston compression is faulty. air will not move around with the refrigerant it will just sit in the highest point of the system.

[Sandro Baptista]

As chemicool said the guage needle moving up and down rapidly on the high side would indicate that the compressor valves or piston compression is faulty. air will not move around with the refrigerant it will just sit in the highest point of the system.

I'm plenty agree.

[Old cooler]

I guess you must mean the discharge/high side then?
Rapid pulsating is certainly the influence of a recip compressor