Polyvinyl Chloride is a hard plastic solid. It comes in a variety of forms, including pipe. PVC pipe is almost the only type of pipe that is used to move water around a water feature and a filter system. It is easily hidden, cost effective, versatile and can hold a lot of water pressure. PVC pipe comes in a variety of lengths and widths. Most water gardening applications require pipe sizes from .5” – 6” wide. These sizes are easily found at a local hardware store.
PVC was discovered by accident on twice in the 1800’s. Henri Regnault discovered it in 1835 and Eugen Baumann in 1872. The both left containers of Vinyl Chloride in the sun and found that a solid white plastic formed through polymerization. They both thought that there weren’t any industrial applications with this new chemical due to its consistency and its difficulty to produce. It wasn’t until 1926 when a scientist named Waldo Semon discovered a way to make PVC more flexible and easier to process. Nowadays, Polyvinyl Chloride is used in: pipe, vinyl records, electrical conduit, window blinds, bottles, toys, electrical cable insulation, various automobile parts, and much more.
PVC pipe has revolutionized to construction industry in the last few decades. It is not only cost effective, but it is also easy to handle, transport and assemble. Polyvinyl Chloride itself is used in everything from sewage lines to the insulation of electrical cables.
There are a wide variety of fittings and couplings available for PVC pipe. There are also a wide variety of valves, pressure gauges, flow meters, probes and other accessories that are easily added to the pipe.
The most common way to join PVC pipe to various fittings is with solvent welding. This is the process: PVC primer is usually applied to the inside of the fitting and the outside of the pipe. PVC primer softens the Polyvinyl Chloride so it welds together easier. Then, a good layer of glue is applied to the inside to the fitting and the outside of the pipe. The two are then joined together.
The PVC pipe and fitting are then bonded together by a process called chemical fusion. Together, the primer and the glue dissolve the PVC surface, forming a strong weld.
PVC pipe does have hazards though. It should not be used as an air line. If too much pressure builds up in the air line, by getting plugged or having a high PSI air pump attached to it, the pipe can explode and cause great bodily harm. The pieces of shrapnel can become lodged in your skin, or worse, in your eyes.
The manufacture of Polyvinyl Chloride creates health hazards too. Certain chemicals used in the manufacturing process cause liver problems and birth defects. Dioxins, the most powerful carcinogens, are released during the manufacturing process and when Polyvinyl Chloride is incinerated at a waste disposal facility.
Thanks to a wide variety of fittings, any angle is possible. This simplifies the construction of a filter system. When piping a filter system, a minimal amount of sharp angles, like 90 degree angles, should be used. These will restrict the flow of water. Also, use PVC pipe that is large in diameter, not only is more water able to flow through, but it will help reduce the amount of friction.
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