Back Pressure Valve, Pressure Maintaining Valve Europe?

[CG43]

Hello HeXx

Found an test from the air of an 2 stage Tuxing compressor on youtube .
In the video you can see the pressure gauge during the sample is 40 bar (588 psi) .
Thats is my answer on youtube .

www.youtube.com/watch?v=temmPJsm7qc

Tuxing TXEDM042 for Scuba?​

Air samples from Tuxing TXEDM042During the test the pressure was only only 40 bar . You can see the gauge .A two stage compressor can run up to 60 bar (588 psi) without burning to much lubriacant oil .But if you fill your tank up to 3000 psi the compressionratio of every stage must be about 14,3and the air in the zylindes become to hot . That's the reason for your bad air and not the fve hour runtime .Sorry but the air you send for the test must be taken at least while the compressor is running a few minutes at 3000 psi or highter pressure , otherwise it is worthless for a two stage compressor without a pressur maintaining valve like your Tuxing .

 

[HeXx]

Hello HeXx

Found an test from the air of an 2 stage Tuxing compressor on youtube .
In the video you can see the pressure gauge during the sample is 40 bar (588 psi) .
Thats is my answer on youtube .

www.youtube.com/watch?v=temmPJsm7qc

Tuxing TXEDM042 for Scuba?​

Air samples from Tuxing TXEDM042During the test the pressure was only only 40 bar . You can see the gauge .A two stage compressor can run up to 60 bar (588 psi) without burning to much lubriacant oil .But if you fill your tank up to 3000 psi the compressionratio of every stage must be about 14,3and the air in the zylindes become to hot . That's the reason for your bad air and not the fve hour runtime .Sorry but the air you send for the test must be taken at least while the compressor is running a few minutes at 3000 psi or highter pressure , otherwise it is worthless for a two stage compressor without a pressur maintaining valve like your Tuxing .

That's how I was intending to send it.
I have filled a scuba tank with 240 bar, now I'm going to send it for analysis even without filtration.
What worries me the most is CO.
By the way, for anyone needing a pmv, the hydraulic sequence valve works flawlessly and costs a fraction of the others on the marker.

 

[CG43]

Hello HeXx

That's how I was intending to send it.
I have filled a scuba tank with 240 bar, now I'm going to send it for analysis even without filtration.
What worries me the most is CO.

Ok , that's fine .

Because the two stage compression don't work well , at least is not good for the air purity,
it is possibel to first run the compressor to a large storage tank (50 L tank) up to 60 bar.
During this the pressure after the first stage must be limited to 8 bar.
After that, only the second compressor stage can be fed from this tank down to a storage tank
pressure of 30 bar.
With a 50 L tank this is 1500 L air , so that you only have to do the process twice.
I know this is a lot of effort, but in this way you have a three-stage compression that never
exceed the pressure ratio of 8 per stage.
From what I have seen from you so far, you are able to build and operate such a plant.

Please post us where and which pmv you bought. Thank you .

Greetings Rainer

 

[Gone for diving]

might be hard on the compressor.
But you could input 100psi into the intake. From your shop air. Will definitely pump more volume but probably hard on the first/ second stage piston.... of the Tuxing

 

[CG43]

Hello

The entrance port of the Tuxing second stage has to be connected to the
(60 bar down to 30 bar) storage tank pressure and the Tuxing output port has to be connected to the
air filter system . It only needs four cheap ball valves and some piping to change from store tank fill
to let's call it "Third Stage Run ".
The second stage is calculated for 300 bar. Inlet pressure 60 bar at 240 bar outlet pressure is not a high load, but there may be a problem with less lubrication if the air from the storage tank contains too little oil mist because the air in the tank is cold.

 

[HeXx]

Hi.
I understand the idea but why not feed 4 to 7 bar on the input of the first stage?
Cheers

 

[CG43]

Hello

Normally you design in such a way that each stage increases the pressure by the same factor. How high the pressure is after the first stage depends on how much the second stage pumps away. In the construction, therefore, a certain ratio is chosen by which the stroke capacity of the second stage is smaller than that of the first stage . This ratio is fixed .
For two-stage compression to 300 bar, I choose a pressure ratio of P2/P1 = 18 per stage. At a pressure of 300 bar at the exit of stage two, the pressure between the stages is then 16.7 bar.
This is the pressure for which the first stage is calculated and you can't increase it without overloading the compressor.
If you fed the first stage with 4 bar, then it delivers much more air. However, the second stage can only pump this amount away at a higher inlet pressure. The pressure between the stages increases with it, which overloads the first stage. This also happens if the last stage no longer pumps enough, e.g. due to wear .
For this reason, pressure relief valves are usually built between the stages.