Water supply is the process of general requirement for supply of water from public water supply system to individual building and subsequent distribution of water to various parts of the building. The water from public water supply system to individual buildings is supplied through pipes. A large proportion of capital is invested on pipes while designing water supply distribution system. The following factors should be considered in selection of pipes.
Various Types of Pipes
These pipes are extensively used for water supply. They are best suitable for long distance pipe lines of high pressure and provide satisfactory performance during service. These pipes have excellent mechanical properties and are ideally suited for welding. The pipes are made in length more than twice the length of CI pipes; which saves in transport, layout of pipe and joining cost. There is minimum damage to the pipes in transportation. The pipes being light in weight are used for large diameter pipe lines.
Main advantage of cement pipes in place of metallic pipes is their corrosion resistance. These pipes are bulky, heavy and require careful transportation and handling. The layout process of these pipes is costlier than steel pipes.
Un-plasticized PVC (UPVC) Pipes
These pipes are rigid PVC pipes. They are light in weight, tough, resistant to chemical attack and large in length. Due to large in length the cost of handling is much whereas transportation and installation cost is less. Smooth internal surface of pipes provide less friction which results in saving of energy. These pipes are not suitable for the area which is very hot.
Installing gas piping
Proper sizing of the pipe is important so that each gas appliance receives enough gas to perform properly. Each appliance has a minimum input demand in BTUs per hour. Black iron and corrugated stainless steel (CSST) are commonly used approved materials. CSST requires certification from the manufacturer for anyone who is going to purchase and install the material. If you are cutting iron pipe, you must ream the cut of your pipe so you maintain the full inside diameter of the pipe. Do not use ground joint unions except directly at the meter or after the shutoff valve at the appliance. Each place where you will have a gas appliance must have a gas shutoff valve. Within the City of Seattle only, any person who installs gas piping on property not under their ownership must possess a Seattle Gas Piping Mechanic License. All gas piping installations require a permit and inspection. Testing the system is your responsibility. The inspector does not perform the test or provide any of the equipment necessary for the test, including test gauges.
An air pressure test is required. The test pressure shall be at least 1 ½ times the working pressure, but no less than 3 pounds per square inch (psi). The test duration shall not be less than 10 minutes. The piping system shall withstand the test pressure specified without showing any evidence of leakage or other defects. Mechanical gauges used to measure test pressures shall have a range such that the highest end of the scale is not greater than five times the test pressure. For instance, a 3 psi test will require a maximum 15 pound gauge. A 10 psi test could be performed using a 50 pound gauge, but not a 100 pound gauge. The piping system shall be under test (pressurized) and the test gauge visible at the time of inspection. Where the gauge does not indicate the minimum pressure required for the test, or any reduction of test pressures as indicated by pressure gauges during inspection shall be deemed to indicate the presence of a leak.
If there is a drop in pressure, check for leaks. Check for leaks by filling a spray bottle with soapy water and spraying the solution on the pipe, where it meets the fittings. Bubbles show a leak and you should repair it appropriately. Continue this process until you have no leaks. Do not use an open flame to test for leaks.