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Sumit
22-07-2011, 03:45 AM
Hi Friends ,

To ensure that there is no further leakage in the chiller , we do pressure testing with Nitrogen.

Firstly, for how much time we should stand this pressure to ensure that there is no further leakage ?

Secondly , how much pressure should be given to the chiller working on R134a and R22 (High limits of pressure are mentioned on the chiller by the manufacturer)

james10
22-07-2011, 06:52 PM
without trying to sound crass i really thimk you should get a professional in to do this for you there is so much that can go wrong.

Josip
22-07-2011, 09:01 PM
Hi, Sumit :)


Hi Friends ,

To ensure that there is no further leakage in the chiller , we do pressure testing with Nitrogen.

Firstly, for how much time we should stand this pressure to ensure that there is no further leakage ?

Secondly , how much pressure should be given to the chiller working on R134a and R22 (High limits of pressure are mentioned on the chiller by the manufacturer)



Just for leak test it is enough to pressurize complete system with nitrogen up to 10-12 bar.

Leave it for 24 hours or 48 hours i.e. from noon time today to noon time tomorrow/day after tomorrow. Write down air temperature and check it again tomorrow.

You need temperature readings in case of different pressure readings .... maybe is not leak in the system just different temperature.

Be careful with safety devices and gauges connected to your unit ... maybe devices or gauges cannot resist that pressure ... it is better to disconnect or isolate them with valves, if ...

You must be very careful and use pressure reducing valve on nitrogen bottle, otherwise you can injure yourself or some other person or ruin chiller.

Please, read carefully my signature ... especially, the last row ....

Best regards, Josip :)

Sumit
23-07-2011, 03:30 AM
Hi Josip,

Thanks for your reply.

I do pressure testing of chiller at least once in a week.But I am unaware about the significance of writing down the " Air Temperature " . As you said, sometimes there is no leak , its just a pressure difference. I will be thankful to you , if you will explain it in.

Josip
23-07-2011, 02:11 PM
Hi, Sumit :)


Hi Josip,

Thanks for your reply.

I do pressure testing of chiller at least once in a week.But I am unaware about the significance of writing down the " Air Temperature " . As you said, sometimes there is no leak , its just a pressure difference. I will be thankful to you , if you will explain it in.

Sorry, this I do not understood ...... why and how you make a pressure testing of chiller at least once in a week .... can you explain that, please ...


Please, carefully read again my answer ;)
You need temperature readings ...just different ..... . if we have a pressure difference -/+ (you can have even higher pressure next day, or the same but still with the leak/s) we have to know why .... due to leak or due to temperature change ....
It is not a good way to tell you all ... I had to learn and you must too :cool: nowadays is easy .... very easy .... in my time there were not internet and not enough books end even not so much knowledge as todays ... so what you learn is yours forever and then you can transfer your knowledge to new generation/s ... agree:)

... there are some formulas to calculate P, V or T for ideal gas ... in your case the V volume is the same .... P pressure must be the same in case of no leak .... but can be different due to environment temperature T ... i.e. air temperature in your room ... that is the reason why we need temperature readings to calculate state of our gas ... nitrogen ....

Be careful .... P and T in formula for calculation are in absolute units ....

Here you can read more about ...
http://en.wikipedia.org/wiki/Ideal_gas_law

hope this will be of some help to you .... if not, come back again, please.

Best regards, Josip :)

Sumit
24-07-2011, 06:36 AM
Hi Josip ,

I got it now, the significance of considering room temperature in pressure testing.

Actually , i work for a maintenance company ; we have contracts of operation, maintenance and commissioning of chiller plants.I usually work on YORK chillers and I found that they are more prone to " GAS LEAK " as compared to other chillers like Trane,Carrier etc.

Thanks for your help and have a great weekend.

Sumit