Air Cooled McQuay Scroll Discharge Line Failure

[trozum]

I have had multiple discharge line crack failures on both circuits on this machine since installation approximately one year ago. It is a 90(?) ton machine serving several airhandlers in a HVAC situation. We have verified charge, repaired cracks, checked all bracing and mounts but the cracks keep happening. The crack has occurred at a tee every time.
My question is to whether any service bulletins exist that address this problem.

[cperk]

I have had multiple discharge line crack failures on both circuits on this machine since installation approximately one year ago. It is a 90(?) ton machine serving several airhandlers in a HVAC situation. We have verified charge, repaired cracks, checked all bracing and mounts but the cracks keep happening. The crack has occurred at a tee every time.
My question is to whether any service bulletins exist that address this problem.

Install the bolt on weights to discharge line, like the new Trane CGAM's use. LOL! But it would probably really work.

[Tech Rob]

There are two things that I know of that cause "cracks" in a discharge line. Overheated and/or overstressed pipe/fittings, and not enough mass in the piping to counteract the pulsation of the discharge gas.

Weights might not be a bad idea.

[Bklyntek]

Add vibration eliminators onto the discharge line to condenser barrel or if its air cooled,be sure to add stabilizing hanger to the outlet side of eliminator. We had this happen to several units in so.florida.

[ga1279]

trozum- How are the compressors circuits mounted ? If they are all mounted on a flat plate that all four feet attach to, make sure the shipping bolts are removed. If they are mounted on 2 parallel base plates leave the shipping bolts in or re-install bolts in those openings, 4 bolts per compressor. The vibration of a running compressor to an idle compressor is what is causing your cracked discharge line.=GEO

[Six]

I have had multiple discharge line crack failures on both circuits on this machine since installation approximately one year ago. It is a 90(?) ton machine serving several airhandlers in a HVAC situation. We have verified charge, repaired cracks, checked all bracing and mounts but the cracks keep happening. The crack has occurred at a tee every time.
My question is to whether any service bulletins exist that address this problem.

Ive had that issue with a couple of 20 ton ICMs with tandem scrolls,

The compressor mounting hardware starts to back out and it causes excess vibration and cracks the discharge line.....at the T.

Vibration is the primary cause of leaks on a discharge line on any machine.

I had to add locktight because even with lock washers they would back out.

Haven't had any issues since and that was 3 years ago.

[freonrick]

most of the cracks I have found was caused by a compressor that had excessive vibration. I do not repair the tee I replace it.

[steveoo]

secure discharge line to the lifting bracket on top of compressor with some kind of clamp.