Pipe sizingThe recommended pipe diameter is based on the calculation of the pressure loss in the pipes. Besides the diameter, the pressure loss depends on the length of the pipe, the pipe material, the flow rate, and the quantity and size of the fixtures to which the pipe is connected. Due to the strength of the fused joints, as well as the minimal friction caused by the Fusiolen® material, it is recommended that the system run at 8 ft/sec rather than the standard 3-5 ft/sec for metal pipe. Principles of calculationTo determine the pipe diameter in potable water systems of buildings, there are many factors to be considered, including:
This section includes charts on the head loss of SDR 7.4 and SDR 11 systems, as well as the estimated GPM based on a flow speed of 8 ft/s. It is important to note the differences between the SDR 7.4 and the SRD 11, as the actual ID’s for both vary slightly. Having a flow speed of 8 ft/s can sometimes allow for downsizing of the pipe when compared against other piping systems (for example, in an application where a six-inch copper pipe would have been used, a four-inch aquatherm greenpipe pipe may be sufficient). However, this is more common when using SRD 11 climatherm® (recommended for heating and cooling distribution and other non-potable applications) and the SDR 11 Fusiotherm® (recommended to cold potable water systems) because the SDR 11 pipes have a higher water content per foot. The following tables contain the pipe sizing: |