I have a chiller replacement application where the existing unit is actually 2 chillers. The name tags identify them as "section A' and "section B" of the same unit, but they have separate piping and electrical feeds. They must have interlocking controls so that at least one compressor from each is running in order not to bypass water through a non-operation chiller. All not really relevant to my question.
I am planning to replace this (2 piece) chiller with a single chiller. It will be dual-fed electrical so that I can use the same circuits, but the piping will only have a single supply and a single return connection. This is my dilemma. 6" supply and return lines leave the mechanical room and drop underground. These lines Tee underground, and 4 pipes pop up at the chiller location. One set of pipes is 6" and the other 5". See attached
My flow rate is 650 GPM with 30% EG. A single pair of 6" lines leave the mechanical room now, so I only really need a single pair of 6" lines at the new chiller. I am verifying pressure drop of old versus new to make sure I have the pump capacity. So my question is, can I cut, cap, and abandon the 5" lines above the ground? This will leave dead-legs where the current underground piping Tees off. Otherwise, I would have to tie the 5" and 6" lines together before connecting to the new chiller. That would mean connecting the 1st and 3rd pipes in the photo and connecting the 2nd and 4th pipes. A lot of extra cost if not necessary. I am just leery of abandoning lines that will still be live and connected to the system. I would have to dig up the parking lot to do it correctly.
Thoughts?
I am planning to replace this (2 piece) chiller with a single chiller. It will be dual-fed electrical so that I can use the same circuits, but the piping will only have a single supply and a single return connection. This is my dilemma. 6" supply and return lines leave the mechanical room and drop underground. These lines Tee underground, and 4 pipes pop up at the chiller location. One set of pipes is 6" and the other 5". See attached
My flow rate is 650 GPM with 30% EG. A single pair of 6" lines leave the mechanical room now, so I only really need a single pair of 6" lines at the new chiller. I am verifying pressure drop of old versus new to make sure I have the pump capacity. So my question is, can I cut, cap, and abandon the 5" lines above the ground? This will leave dead-legs where the current underground piping Tees off. Otherwise, I would have to tie the 5" and 6" lines together before connecting to the new chiller. That would mean connecting the 1st and 3rd pipes in the photo and connecting the 2nd and 4th pipes. A lot of extra cost if not necessary. I am just leery of abandoning lines that will still be live and connected to the system. I would have to dig up the parking lot to do it correctly.
Thoughts?
