Purging with Nitrogen

[summerblues]

the condensing unit I'm disconecting does not have king / service valves, they are very old.

I need to purge the lines with nitrogen to clean them out.

So when I cut the lines there will not be any conections for the nitrogen hook up,

do they sell rubber type connection like that found in a Gallow Gun ?

I assume this type of rubber connection should work for purging.

[coolguysfl]

Your NEW condenser will have all the fittings required to clean the system & restore cooling.

Your EPA qualified contractor will have the skill set, tools and refrigerant recovery equipment to handle this in a snap.

Willful venting of refrigerant is a federal offense.

[summerblues]

I am the Tek on this job.
We are recovering the charge,
but afterwards I thought it may safer to purge the excess oil
or debris before brazing the joints.

[corny]

Why are you blowing out the lines...??? Give a few more details of what you are doing and why and you will get better answers....

[comfortdoc]

Originally posted by summerblues
I am the Tek on this job.
We are recovering the charge,
but afterwards I thought it may safer to purge the excess oil
or debris before brazing the joints.


You really should register as a professional. Most of your posts belong in that area and most of your questions have been answered there already.

[coolguysfl]

Sorry - I did'nt pick up that you were in the trade. Then I'd use a flush kit, followed by a nitrogen flush, evacuate & break with nitrogen. If you're cleaning up a burn out, you might be well off removing the metering device.

The presence of a small nitrogen amount being vented while brazing is a 1st class procedure to avoid oxidation from the heat whole brazing.

I know of no rubber connections to facilitate the nitrogen flush, you'll have to weld a schader in.

[corny]

Originally posted by summerblues
I am the Tek on this job.
We are recovering the charge,
but afterwards I thought it may safer to purge the excess oil
or debris before brazing the joints.


You must have posted this as I was posting my previous answer.....

anywho.... get some schrader valve access fittings from the supply house...get some caps to fit your line at the supply house...solder fittings into a hole in the caps...attach cap to line...dont have to solder...and connect nitrogen bottle to fitting and purge...hold cap with access fitting on pipe just in case it wants to blow off....but it shouldnt if you are just blowing thru the copper...

just blowing nitrogen thru wont do much...oil sticks to the sides of the tubing and you really need to push a solvent thru to clean the tube walls.... if the oil is not burnt and the same type as whats in the new equipment I wouldnt worry about cleaning the lines...

a good evacuation and a liquid line filter drier should be plenty of protection for a non burn out equipment replacement.

[summerblues]

I'm installing a new condensing unit only.

I am blowing out the lines with 100 PSI Nitrogen, mostly to clear out old oil, or as much of it as I can.We are talking a bout a 35 year old unit , 2 tons, residential.

would it make more sense to just connect the new condensing unit, without opening the service valves of course, and blow out oil through the schrader port ?

[coolguysfl]

That's how I'd do it - but remove the schader cores for best flush & evacuation.

But if you suspect contamination or you want to remove oil - a flush kit is required.

[summerblues]

Thank you

I'll look into getting into the Pro section

[mark beiser]

I recommend you blow the system out before brazing up the lines to the new condensor...

If you don't have a fitting that will make a decent seal against the end of a line, you could try butting the end of a refrigerant hose up to the line and wrapping a bunch of tape around it. Rollmastic would hold it.

[RoBoTeq]

Originally posted by summerblues
I am the Tek on this job.
We are recovering the charge,
but afterwards I thought it may safer to purge the excess oil
or debris before brazing the joints.


This kind of discussion should really not be done in this area. You really should regester as a pro member so issues like this can be discussed in a pro forum.

[jrbenny]

Summerblues...

Follow the link (http://www.hvac-talk.com/vbb/showthread.php?threadid=116113) for professional membership instructions.