The Challenge

A Boston-based surgical center required an upgrade of its reverse osmosis (RO) water system feeding various central sterile applications. The surgical center was eager to achieve AAMI TIR 34 recommendations for central sterile water. The center realized that its legacy high purity water system installed by a former vendor was incapable of generating the desired water quality. Frustrated by these results, the customer sought to replace the entire system and contacted Pure Flow for an evaluation. Upon completing its evaluation, Pure Flow determined it would be possible to achieve AAMI TIR 34 water quality by making modifications to the existing equipment, and consulted the customer to pursue an upgrade rather than replacing the entire system.

Our Solution

Pure Flow determined that it was possible to upgrade the system rather than replace it entirely. The existing system had a handful of design flaws that would need to be addressed:

  • UV was sized for only 50% of the required distribution flow rate
  • Loop plumbing had 6″ dead legs at each point of use, creating an ideal environment for bacteria growth
  • Ball valves at points of use also promoted bacteria growth
  • Final filters were neither tight enough nor not absolute rated, and did not have 222 O-ring style connections. As a result, bacteria could easily flow through final filters.

Pure Flow renovated the entire distribution system adding a properly sized 254 NM UV for disinfection. Pure Flow also removed all loop dead legs, adding sanitary needle valves rather than ball vales. A 0.2 micron absolute final filter was installed to restrict bacteria entry to the loop. The entire system was disinfected and tested for bacteria and endotoxin prior to start up to ensure that TIR 34 requirements were met. Finally, Pure Flow worked with the customer to implement a sampling and preventative maintenance schedule to ensure that AAMI TIR 34 water quality requirements would be continuously met going forward.

Pure Flow is experienced in the design, installation, and servicing of ultrapure water systems that exceed the stringent water quality requirements for standards such as AAMI TIR 34, USP, and ASTM Type 1.

AAMI TIR 34 Water Quality Standards