High Purity Water System for Hospital Medical Device Cleaning
Smith Engineering Inc (SEI) recently custom designed and installed a High Purity Water Treatment System. The water treatment system was engineered to meet AAMI-TIR 34 water Standards for Medical Device Reprocessing. Design considerations included various types of Medical Device Reprocessing and cleaning Equipment with unique individual water quality requirements and specifications used for decontamination processing system standard operational practices (SOP). Equipment design scope included feed water for steam generators, ultrasonic washers, sterilizing washers and pre-wash rinse stations.
The system design included uninterrupted DI tank service during installation and DI Skid design is engineered to allow DI tank exchanges without disruption to processes, allowing uninterrupted high-purity water service supply during DI tank exchanges and service.
This system included alarm set points tied to Hospital Building Maintenance System (BMS). When water quality reached minimum water quality setting, an alarm notification is sent to Hospital maintenance, which then is sent to Smith Engineering DI dispatch (Smith-Link). This program maintains continuous high-purity water supply. An audible alarm and DI Water quality lights are located in the Hospital Decontamination Room in personnel viewable area providing assurance of good water quality should water reach a low limit quality during processing.
The system includes water leak detection and alarm system in equipment area. This leak detection device is tied to an alarm sequence to Hospital BMS. This alarm alerts maintenance staff by email and/or text message. If not acknowledged at equipment control panel in a given time frame when alarming, the system shuts down and an actuated inlet city water supply valve closes to prevent flooding.
Smith Engineering designed a cost-effective method to meet various equipment water purification requirements and maintain AAMI-TIR 34 water Standards in their process including proper Loop design.
Coupled with SEI Purified (Ultra-Pure) Water System is a Loop designed to maintain high purity water to process managed use-points which protects the integrity of Loop water supply by isolating appropriate use-points under SEI use-point management best practices.
The High-Purity Distribution Piping Loop is fed and purity maintained by SEI DI System. Loop materials consist of Teflon (PFA) tubing, flared fittings, zero-dead-leg (ZDL) valves and Air Actuated (AA) ZDL valves. Loop is continuous flow through design and returns to distribution pump inlet for continuous recirculation passing through DI system to maintain water quality to control microbial contamination.
In some areas unavoidable water supply dead-legs to feed equipment that potentially could produce contaminate issues back to the Loop have been isolated from main Loop. These areas have been mitigated through the use of actuated zero-dead-leg diaphragm valves which open when water is supplied to equipment, then close to avoid stagnant dead-leg between equipment inlet and Loop supply open access to main Loop. For instance, flow goes in one direction to the washer final steam rinse, then is closed off to main Loop when flow stops.
Looped High-Purity deionized water is disinfected by Ultra-Violet light system (UV) to render bacteria inactive, then dead cells are removed by final filtration. Water that enters the distribution loop and is not consumed by the process returns to inlet of distribution pump. This circulation keeps water quality and disinfection polished within distribution loop.
This system has an SEI preventative maintenance schedule to ensure reliable consistent water quality to meet or exceed AAMI guidelines. The water quality is verified by NIST traceable monitor and by sanitary sampling points for sampling to test for microbial contamination, to insure purity.