Safety Factor in polyethylene pipe
Safety Factor in polyethylene single- wall pipe
Safety factor (SF) can be 1 (1.25), 1.6 or 2. Safety factor is indicator of ensure from life span of polyethylene pipe. By increasing of SF, resistance of polyethylene pipe increases at pressures above specified limit. SF of polyethylene pipe is one of characteristics that is presented in the specification table. SF of polyethylene pipe Which is presented in the national standard of Iran, as well as the German DIN standard and all the standards of the PE pipe in the world, is indicator of ensure from life span of polyethylene pipe.
For general use of polyethylene pipe , SF of 1.25 and in cases where there is a higher sensitivity such as main transmission lines or Firefighting lines, SF of 1.6 and 2 are used. For example, if polyethylene pipe is produced with a safety factor of 1.25, this means that amount of pressure real bearing in this polyethylene pipe is 25% higher than its nominal pressure. For example, if the nominal pressure of the polyethylene tube is 10 atmospheres, nominal bearing of its pressure is 12.5 atmospheres.
Note that, in order to select polyethylene pipe, pipe nominal pressure must first be determined, then, on the basis of required safety factor, select desired polyethylene pipe. Conversion of nominal pressure by multiplication of numerical value of safety factor in pressure real bearing amount and then selecting of polyethylene pipe is incorrect. For example, if we need a pipe with nominal pressure bearing of 12.5 atmospheres, it is a mistake work that we choose a pipe with a pressure of 10 atmospheres and safety factor of 1.25. We need to choose a polyethylene pipe with a nominal pressure of 12.5 and required safety factor. It should be noted that thickness and weight of polyethylene pipes varies with different safety factor, and in designing and signing of performance contract, this should be specified and characteristics of polyethylene pipe should be fully mentioned.
Carefully check the specifications table of polyethylene pipe and see safety factor for each pipe. And now a simple solution for determining and detecting polyethylene tube SF, For example, for pipe 200 with PN16, we want to produce a higher safety factor and SF 1.6, what specifications should be considered in the specification table? It is very simple, Specification of the PN20 put as reference, and polyethylene pipe is produced according to this specification.