Piping and Plumbing
Piping the Swimming pool system
The plumbing system is designed to circulate all the water from the pool through the filtration system. Normally, water is drawn from the pool through the main drain and the surface skimmer; passes through suction lines to the pump, filter, and heater; and then returns to the pool via return lines.
The main outlet or drain is a precast concrete or plastic sump, either covered with a grill or designed with an anti-vortex feature to lessen the chance of a child being trapped by the suction.
Located in the deepest part of the pool, the main drain serves as a collecting point for debris and draws off dirt that settles in the bottom. It also allows for complete draining of the swimming pool. Another intake can bee the vacuum line for the cleaner, though in most pools this connection is part of the skimmer.
Suction and return lines must be of adequate size if the filter system is to work properly. The number and location of the return lines and inlets required for proper circulation of the water in the pool depend on the pool's size and shape. Swivel fittings at the ends of the return lines allow the water flow to be direct the surface water toward the skimmers. Proper circulation is essential for complete filtration of the pool water and for thorough mixing of the chemicals.
In Thailand *, the arrangement should encourage a clockwise movement in the pool water. In pools of complex shape, the inlets should be located so that there are no dead spots. It's desirable to maintain equal flows through the inlets. This can be done by progressively reducing the pipe size of the return line between one inlet and the next.
Though copper pipe is acceptable, most pool builders use one of several types of plastic for piping and fittings. Plastics' low cost, complete resistance to corrosion, good flow characteristics, flexibility, and ease of installation make it practical for all pool piping. The plastics are joined with a solvent welding compound and the flexible types can be formed easily without kinking. (Caution, plastic pipes and heaters do not mix well).
Some local building codes have not yet accepted plastic pipe; most that do specify the plastic types and wall thicknesses they allow. Be sure to check the codes in your area.
Some types of automatic pool cleaners require piping that is built into the pool wall or installed while the pool is being built. Decide what cleaner you will use before you build your pool.
Hooking up the Spa
If you've decided on a spa as part of your swimming pool, or if you've located one close by, you can use the pool support system for the spa. If your pool relies on solar heat, you'll want a gas or electric heater for the spa.
* For swimming pool builders in the Northern Hemisphere they should encourage a clockwise water movement in the pool, for pool builders in the Southern Hemisphere they should encourage a counter clockwise water movement.