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SECONDARY REFRIGERANT SYSTEM IMPROVEMENTS General Substantial corrosion has deteriorated parts of the secondary refrigerant or brine system including the brine pumps, piping, valves and supports. Regardless of which chiller option is selected the improvements to the brine system recommended in this section are necessary to provide a safe, efficient and long lasting system. Some improvements to this systeEn were completed 'm or around 2001 and include changing six relief valves (should be replaced every 5 years in an ammonia system). Several of the puinps impellers were trimmed to eliminate the need to throttle valves to adjust for the actual head or flow conditions in the rink floor. This improves the eff"iciency of the pump motors. lf a calcium chloride solution is again used in this system and given the long downtime o f the systen3 during the off season, an evaluation should be perfarmed to determine whether ar not the existing brine system piping can be modified to allow for continuous or periodic circulation of the solution within the mechanical room when the oval is shut down. This may assist in bleeding air from the system and ininimize the corrosion inside the piping system. The temperature of the brine would have to be considered since the refrigeration system will not be operating. Recommended Improvements The following improvements are recommended: I. Remove and dispose ofthe existing calcium chloride mixture. 2. Replace all butterfly valve inseits to assure proper operation. 3. Recondition all check valve inserts to assure proper operation. 4. lnstall pup pieces on tre 16" diameter pipe on each end of the chiller. This will allow easier removal of the chiller end bells when service or access to the chiller is required. 5. Replace all auto air vents on the system to assure proper operation and release of air in the system. 6. Recondition the rink pumps. This includes replacing the seals, bearings and re-insulating the units. lf ethylene glycol is used in place of the existing calcium chloride solution it will cost approximately the same amount to replace the pumps in their entirety cornpared to replacing parts of #he pumps including the impellers. 7. Replace and install thermometers and pressure gauges for monitoring the system 8. Replace the valves ot� the drain line to assure proper operation. 9. Replace the flow switch at on the pump discharge line to assure proper operation. 10. Replace the support columns for the header pipes. They are in poar shape and should be replaced for safety reasons. 11. Evaluate ��- feasibility of modifying the brine piping system to allow for continuous or periodic circulation during the off scason.