Describing Sizing of Plumbing Piping

Sizing of Plumbing Piping

Plumbing must he sized enough to allow fixtures to operate properly and for proper draining and venting. The size of water supply piping is based on these conditions:

Amount of water needed.

Supply pressure.

Pipe length.

Number of stories to be supplied.

Flow pressure needed at the farthest point from the source.

The size of drainage piping is based on standards established for the type of fixture and the average amount of waste that can be discharged through the fixture in a given amount of time. The size of vent pipes is based on the number of drainage fixture units that drain into the waste portion of the vent stack.

American National Standard taper pipe threads are the standard thread used on pipes and pipe fittings. These threads are designed to provide pressure tight joints or not, depending on the intended function and materials used. American pipe threads are measured by the nominal pipe size, which is the inside pipe diameter. For example, a 1/2" pipe size has an outside diameter of Bier. Pipe threads are identified using a thread note such as 3/4 I4NPT, where the 3/4 is the nominal inside diameter of the pipe. 14 is the number of threads per inch. and S: r stands for National Pipe Thread.