Double-check on check valves
I particularly enjoyed reading April’s Letters to the Editor and would like to expand on a letter sent in by Dave Judy of Water System Services, Oxford, Ohio. Dave very astutely pointed out (in reference to: Beauchamp, John, “Groundwater: Custom Plumbing for Wells—A Valve for Every Occasion,” WC&P, December 1999, pp. 50-53) that the installation of check valves and pressure regulators after water softeners requires the installation of proper expansion equipment on the hot water heating equipment, among other things. This is just the tip of the iceberg.
As a plumbing professional first and foremost, I am constantly amazed with the complete disregard (or ignorance) of many of the residential water conditioning and purification system installers for their locally adopted codes. This has been true in my experience from installation of check valves without any consideration for hot water expansion to connection of water conditioning and purification systems’ waste water drain piping into the building drainage system without the use of approved backflow or airgap devices… to the undersizing of equipment inlets and outlets as they relate to the actual required supply pipe sizing… to use of unapproved piping materials to and from the water conditioning and purification equipment, to… I could go on. These installations have been and will continue to be the downfall of the industry that this magazine represents.
There’s no industry in the history of modern civilization that has had a greater positive impact on the health of our country, in my opinion, than the plumbing professional. These illegal installations not only serve to aggravate the homeowner when he/she tries to sell his/her house, but are also potentially dangerous to the heath and well being of the homeowner that they were initially installed to protect. They serve only to damage the reputation of our combined industries as well. Until these installers are properly trained (and held accountable) for their work, the residential water conditioning and purification industry will be looked upon by their peers in the plumbing industry as second class citizens.
Jim Ellison, Senior Estimator
Back to iron removal in Saudi Arabia
Don’t forget ‘Coke’
As I read the answer to you Ask the Expert column item “Iron and Saudi Arabia” (WC&P, January 2000, p. 20), I kept hoping your expert would get around to coke tray aeration and suggest anthracite instead of sand. Once in operation, no additional chemical treatment is required and no resin regenerates are needed.
A coke tray aerator is three or four platforms (trays with holes in the bottom) stacked on top of each other with a few inches of space between each tray. The trays are filled with foundry coke. Iron-containing water is allowed to flow through each tray and, on the way, the dissolved iron precipitates. The water is then collected in some sort of tank to be re-pumped through a filter. Properly designed, you can do the whole job with gravity.
At start-up, the darn thing doesn’t seem to work; but within a few days, it will. The reason is the iron that precipitates on the coke is the catalyst that causes the dissolved iron to come out of solution (along with oxygen) and it takes a few days for enough iron to develop.
I’d say water is precious in Saudi Arabia and, therefore, they should be thinking graded anthracite instead of sand because anthracite is about half the weight of sand so it only requires about half as much backwash water. Good idea to collect the backwash water, let the suspended solids drop out and recycle this water, too.
Frederic Friar, President
What about RO?
The item “Iron and Saudi Arabia” in the Ask the Expert column (WC&P, January 2000, p. 20) caught my eye. I’m surprised that reverse osmosis and other membrane systems are not mentioned as the most efficient treatment modality. We have made great progress in using low dosages of appropriate antiscalants to treat feed waters to RO systems that contain more than 7 ppm of iron. In central Canada, and many areas around the world where municipalities have to deal with high iron and other contaminants in well waters, simple membrane systems with antiscalant injection have efficiently and economically replaced traditional treatment methods mentioned in the column. In addition to iron, these systems also remove a host of other contaminants in water and make possible, through blending, the meeting of a wide range of water quality requirements. This modality of purification also presents the least burden on the environment and maintenance of the plant.
Robert Y. Ning, Ph.D., Vice President, Science and Business Development
King Lee Technologies
San Diego, Calif.