London 1999 Dunham Bush Chiller 407C 300kw 2no compressors,discharge pipework 2 1/8

Fault, fracture on this pipework 2n/d 3rd year working
Could not get answers to the problem via the manufacturer.very high frequency vibration from pipework when fully loaded.Approx 2mtr run pipework to air cooled condensing coil.
On the same site is an Airedale air cooled chiller R22 200kw 1 7/8 discharge pipework approx 4mtr run to condensing coil hanging from threaded rod ie allowed extensive movement. Decided to extend pipework on DB chiller to approx 4mtrs.Sometime later one of the coils was replaced the engineer decided to return the discharge pipe work to its original length when a couple months later the pipework fractured followed by a serious malfunction compressor pistons.
I have heard that reciprocating compressors of this duty should not run on 407c please advise , as far as i know its an on going problem,To be continued ie an interesting problem with the Airedale !!!