Potable water systems, whether in water filtration, beverage dispensing, life science, bottling or semiconductor are much more than the sum of their individual parts. A thorough analysis of the environment in which the system will be operating -- in addition to the selection of system materials, connectors, tubing, and accessories – is needed to ensure trouble-free, long-term system performance.
The following is a case study of an existing potable water system in a dental office that broke down due to poor planning and component selection and the steps taken to rectify the problems.
The dental office
The service director of a water treatment company received a frantic call from a dental office receptionist explaining that the potable water throughout the office had an unpleasant taste and was releasing a foul odor. The central Reverse Osmosis (RO) system was producing unusable water at the office’s water cooler in the patient lounge, the spigot in the employee break room and in the dental operatories where dental treatments are performed. Further, it was noted that there was a pungent odor emanating from the sink every time the tap water was turned on in the break room, while all the tubing supplying the service locations was turning green.
Diagnostic survey and audit
A diagnostic survey of the entire water system, plus a site audit of the existing installation and plumbing service to the building, revealed many issues, including:
- The static water pressure to the building measured 112 psi with no pressure regulator on the incoming service main.
- A leaky self-tapping valve was in use for the under-sink RO unit installed in a way that was a plumbing code violation.
- The RO drain saddle was mounted downstream of the trap - another code violation.
- Cleaning chemicals and a box of dishwashing compound under the sink were causing corrosion and oxidation to the plumbing.
- Purveyance tubing from the RO system was secured to the wall with small clips and the horizontal runs were drooping. The tubing was routed above the drop ceiling in several locations causing the tubing to be exposed to light and radiant heat from the lighting fixtures and nearby HVAC ductwork.
Following acceptance of a comprehensive proposal to restore high-quality drinking water to the dental office, the water treatment company’s corrective actions included:
- Removal of the condemned existing residential RO and related purveyance tubing
- Repairing the plumbing and sanitary piping under the break room sink
- Cleaning, sanitizing, performance testing and recommissioning of the patient lounge water cooler
- Installation of a code-approved pressure regulator at the main water line set to 60 psi with pressure gauge
- Installation of a light-commercial RO system with a cellulose tri-acetate (CTA) membrane and six-gallon accumulator in the utility closet
- Installation of 0.375-inch ID CPVC rigid piping using mounting and installation best practices
- Installation of service valves at each service outlet for isolation, removal, and replacement of chlorine
- Addition of taste and odor (CTO) POU filters
- Installation of non-translucent, FDA-approved flexible antimicrobial polyethylene tubing connections at each service valve, POU CTO filter and connections off the water cooler, remote RO spigot on break room sink and dental operatories with compatible thermoplastic fittings
- Performance of pressure-test and purge purveyance piping, valves and tubing of air and fill with supplemented chlorinated RO water for disinfection; flush cooler, remote RO spigot and dental operatories
- Attached CTO POU filters and purge of air
- Connection of final filtered water to cooler, remote RO spigot and dental operatories
- Testing of product water for chlorine removal
Subsequent to the plumbing inspector’s sign off, the service director took the customer on an inspection tour to appraise the taste and quality of the water and confirm her satisfaction. The customer approved the new installation and accepted a recommended service schedule for the new potable water system.
Download our White Paper covering two case studies on potable water systems. Learn the importance of project planning, component selection, and understanding environmental conditions in potable water systems.
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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.
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