Laserfiche WebLink
r <br /> Exhibit A <br /> DESCRIPTION <br /> Task A = CHEMICAL FEED SYSTEM INSTRUMENTATION UPGRADES / IMPROVEMENTS <br /> All items include PLC and HMI modifications , test , verifcation and copy to other sites with <br /> alarm/shutdown setpoints and timer setpoints hardcoded in the PLC unless otherwise stated . All <br /> instruments , hardware , speed controlled chemical pumps and wiring is assumed to be installed now or <br /> by others during implementation of these changes . <br /> 1 Instrumentation permissives to acid pump controls : <br /> a Low permeate pH - time delayed shutdown of plant with flush <br /> b Low low permeate pH instantaneous shutdown of plant with flush <br /> c Low finished water pH alarm <br /> d High finished water pH alarm <br /> e Low raw water pH - operator adjustable time delay to shutdown plant without flush <br /> f Low low raw water pH - shutdown of plant without flush <br /> g Low low raw water pressure - shutdown of plant without flush <br /> h Low blend pH - time delayed shutdown of plant without flush <br /> I Low low blend pH - shutdown of plant without flush <br /> 2 Operation of caustic pumps to be dependent on permissives for flow : <br /> a High pH alarm and time delayed shutdown of pumps <br /> b High high pH shutdown of plant without flush <br /> 3 Operation of chemical pumps should be dependent on permissives for pump skid status : <br /> a Zinc orthophosphate pumps should be flow paced based on permeate flow <br /> b Hydroflousilic acid pump should be flow paced based on finished flow (currently based on high service <br /> pumps ) <br /> c Permissive to run zinc orthophosphate pumps if there is a skid on (currently based on high service <br /> pumps ) <br /> d Permissive to run hydroflousilic acid pump if the high service pumps are on (currently based on raw <br /> water) <br /> Additional Items <br /> 1 Install software switches as required . Plant currently has totalizers only. - 2 days <br /> 2 Programming for automatic proportional adjustment of sodium hydroxide based on pH at degasifier <br /> output . <br /> 3 Programming for silt density index monitor to be installed on raw water feed line . <br /> 4 Raw water turbidity meter - online , high and low alarms with operator adjustable time delays to <br /> shutown the plant without flush . <br /> Task B - PLC INSTRUMENTATION UPGRADES/IMPROVEMENTS <br /> Page 1 File : South Plant SCADA Quotation from CSD <br />