High Purity Water Design Parameters
Materials
- Polyvinylchloride (PVC) schedule 80
- Must be cut with an approved PVC cutter all burrs cleaned off. Chamfering tool to be used to round edges.
- Polyvinylidenefluoride (PVDF)
- Polypropylene (PPE)
- Stainless Steel (Heat Sanitizable)
- Use of any other metals other than 316 SS is not permitted.
Installation
- 90 degree turns the turns should be accomplished with 45 degree angles. When at all possible, a return loop should be used to minimize bacterial growth through movement of water in the system.
- Return velocity must by a minimum of 3FPS with averages 4-7 FPS. Much higher than that you can get noise.
- Dead legs must be avoided. The length of an unused portion of pipe should be between 3-5 times of the pipe diameter as a maximum. Best practice is 3 times when at all possible. Dead-leg definition: An unused portion of pipe greater in length than six diameters of the unused pipe measured from the axis of the pipe in use.
- Approved ball true union valves should be used that are less restrictive than gate valves.
Water Storage
- Storage of the water should be in a conical bottom tank if cleaning are to be done on a regular basis. Spray balls or a spray bar have the added advantage of reducing bacterial growth in theory.
- A hydrophobic vent filter should be installed on the tank and a sealed system otherwise. This is to control airborne bacteria from entering the tank.
See also our industrial and ultrapure water technical articles and information on industrial reverse osmosis and industrial water softeners.
