BS ISO 4437-3:2014

1   Scope This part of ISO 4437 specifies the characteristics of fusion fittings made from polyethylene (PE) as well as of mechanical fittings for piping systems in the field of the supply of gaseous fuels. It also specifies the test parameters for the test methods referred to in this part of ISO 4437. In conjunction with ISO 4437-1, ISO 4437-2, ISO 4437-4, and ISO 4437-5, it is applicable to PE pipes, fittings and valves, their joints, and joints with components of PE and other materials intended to be used under the following conditions:

       a)  the maximum operating pressure (MOP) is based on the design stress, determined from the compound minimum required strength (MRS) divided by the  C  factor, and taking into account rapid crack propagation (RCP) requirements; 
   
   
     
       b)  a temperature of 20 °C as reference temperature for the design basis. 
   
 


 
   NOTE 1  For other operating temperatures, derating coefficients are given in [ISO 4437-5:2014](/catalog/ISO%204437-5%3A2014). 


 
   NOTE 2  It is the responsibility of the purchaser or specifier to make the appropriate selections from these aspects, taking into account their particular requirements and any relevant national regulations and installation practices or codes. 

This part of ISO 4437 is applicable for fittings of the f...