Having potable water at our fingertips is something many of us take for granted. For those in facility management, this can be a significant challenge. Water pressure, temperature, environmental conditions and hostile environments can all affect a facility’s water. Only with the proper water solutions will a facility be able to count on dependable, treated potable water.
Following is a case of an existing system that eventually broke down due to poor planning and component selection, and the steps taken to rectify the problems.
Case: The community center
This case involved a community center that was used by residents and businesses for various events and activities. A service director from a water treatment company was dispatched to the community center to investigate a complaint of “bizarre-smelling water” from a central RO system. Upon inspection of the entire potable water system, the service director discovered the root cause of the offensive smell in the water was directly related to hostile environmental conditions that contaminated the system and purveyance plumbing.
The centralized RO system was installed in the center’s mechanical room, which was separated by an open breezeway to the main structure that housed the kitchen area, ice makers, steamers, pot fillers, coffee makers, soda machines and drinking fountains.
The accumulated RO water entered a bank of activated carbon filters and then exited the mechanical room through a hole in the outside wall and then to direct burial of the tubing in the ground, where it continued for 90 feet (27.4 meters) before rising out of the ground to enter the back wall of the community center for access to the kitchen area. The purveyance tubing was clear 0.75-inch (19.05-mm) ID-braided, reinforced PVC hose, connected with plastic barb fittings and hose clamps. There was evidence of damaged hose due to sunlight exposure, as well as damage from grounds maintenance and other routine activities at the facility.
Inside the kitchen areas, inspection revealed algae growth in the tubing branches that serviced the POU connections.
The RO system was in good working order, requiring only the replacement of TFC membranes with commercial-size CTA membranes. Restoration of the purveyance piping would comprise the bulk of the work.
The reconfiguration and restoration consisted of:
- Removing all pre-existing purveyance hose, fittings and clamps
- Replacing TFC membranes with CTA membranes on the RO system
- Installing rigid 0.75-inch CPVC piping for purveying the purified water to the kitchen areas of the community center, with the piping anchored and routed through the block walls above the entry door, encased in double-containment piping in the breezeway and insulated to protect from freezing and damage.
- CPVC piping to continue throughout the community center kitchen areas, with service-valve terminations at each POU outlet
- Installing non-translucent, flexible FDA-approved antibacterial polyethylene tubing at each service valve outlet, POU fixture chlorine taste and odor filter and fixture connections with compatible thermoplastic fittings
- Purging, flushing, pressure-testing and sanitizing of all purveyance piping, tubing and fixtures serviced by the RO water
This case was an actual event that clearly shows what is required to provide dependable, treated potable water service for health-related and food-service establishments. It is also an example of installations where flexible tubing or hose products may only be a part of a total material selection for a given project. The convenience of flexible tubing and hose products may make short work of a project, but in many cases fail because of poor project planning and understanding of environmental conditions that will affect the long-term performance of a potable water system.
The water usage, in this case, is what is referred to as “intermittent usage” where there may be as little as one day or as many as several weeks when there is no water usage. For that reason, it was important to maintain detectable chlorine throughout the accumulated water tanks and purveyance piping. Therefore, the CTA membranes were specified to allow chlorinated water to permeate the (chlorine-tolerant) membranes. Just as in a municipal water system where water is chlorinated to prevent bacterial contamination, these systems benefited from residual chlorine in the purveyance plumbing to maintain bacteriostasis of the RO water. The chlorine is then removed just prior to dispensing at the POU fixture(s) by the CTO filters.
The importance of assessing a project and selecting the right components for any application should never be taken lightly. Final selection of thermoplastic fittings, tubing and accessories is the responsibility of the person(s) specifying them for a particular application.
Author, Gary Battenberg is a technical support and systems design specialist with the Fluid System Connectors Division of Parker Hannifin. He has 35 years of experience in the fields of domestic, commercial, industrial, high-purity and sterile water treatment processes. Battenberg has worked in the areas of sales, service, design, and manufacturing of water treatment systems and processes utilizing filtration, ion exchange, UV sterilization, reverse osmosis and ozone technologies.
Submitted by Traci Simmons, marketing services specialist at Fluid System Connectors Division, Parker Hannifin.