Camilla C, Brice W, TJ S

Following the procedure written out by Alastair - T1600050 - today we did a full flush of both chiller lines with ~13gal each.

The last time a full flush was done, and not just refills from line leaks or chiller swaps, was back in 2016 (alog30017). This is notably, much longer than the 6mo service interval the manufacturer recommends. Just like back then, after turning off the lasers, power supplies, and AA chassis, we disconnected all electrical and tried to drain the chillers to start. We struggled to get much out of the chiller via the drain pipe, but a trickle would come out of the process input if the ball valve on the back of the chiller is set to a 45deg angle. After the chillers were mostly drained, we tried to wipe the reservoirs to get out any junk that was in there. We then set up a hose with a quick connect and connected it to the process input line and ran it to a bucket below the mezzanine to avoid carrying large quantities of water down those stairs (see attachment 1). The process output was hooked up to the chiller, then with two people on the mezzanine and one below to watch the bucket and hose, we turned on a chiller and filled the reservoir as the level dropped. We put about 13 gal through the system for each before turning off the chiller, which should be more than each system contains (alog30638).

Seperately, I noticed while we were swapping the TCSY laser that some of the 1/4" tubing connected to the RF driver felt softer than others also connected to it. Turns out, 2 of the 8 connected to it are a different type - Tygon 2001 (softer) vs Tygon2475. According to a data sheet I found, the 2001 has a max working pressure of  30psi compared to the 2475 max at 50psi. We should really think about replaing all of these lines post O4, but I'll need to look into how much pressue these lines actually have.