Swapped out the PSL in-line filters in the chiller room. The new filters are 1.0um pleated; replacing 0.5um blown-matt surface filters. The new filters are higher flow with less back pressure. 

   The original filters were causing the operational pressure to rise and were lowering the coolant flow through the system. The posted plots show after the filter change the PSL cooling pressures did drop and the various flows increased. After replacing the manifold (see aLOG #28652) we were able to adjust the pressure regulators in the PSL to bring the line pressure below 4.5 bar. 

   Will continue to monitor flows and pressures until satisfied all is well.