adding a new circuit in a refrigeration rack

[friocold2008]

Hi everyone:

I would like to ask you what would be the best way to add a new refrigeration circuit to an existing rack.
The suction and liquid manifolds are made of 10 cm and 7 cm OD copper pipe respectively. I know that I must shut down all circuits and compressors, recover the refrigerant in each manifold, and then punch a hole and braze a copper pipe with a shut-off valve on it. What I´m not sure about is the correct way of doing this procedure while trying to avoid the entrance of debris into the manifolds.

[Porkington]

The obvious answer is you cant avoid it totally. No matter how careful you are some swarf, debris will enter the system.

The only thing you can do is make sure you clean the system afterwards by changing any filters you have in place.

[tony--1]

You need to know if you have spare capacity on the pack . If you just put extra cases/coldrooms on will they work ?

[Brian_UK]

Before you punch/drill into the pipework pressurise it gently with OFN.

Drill a small pilot hole and then enlarge the rill size until you rach your target size.

You may need to increase the OFN flow to increase the pressure within the pipe.

If you are lucky then the small particles will have been blown out of the pipe.

[smilies]

Before you punch/drill into the pipework pressurise it gently with OFN.

Drill a small pilot hole and then enlarge the rill size until you rach your target size.

You may need to increase the OFN flow to increase the pressure within the pipe.

If you are lucky then the small particles will have been blown out of the pipe.

I agree with this method. For larger lines, I've used snips with luck. Have extra nitrogen handy and make sure there are some felt type filters in all the suction canister shells and then remove/replace after some run time.

[friocold2008]

Thank you for all your guidance. Now I have a better idea on how to approach this job. I thing I might end up using a combination of all of your suggestions. This job is to be schedule for next weekend. I´ll keep you informed. Best regards.