BS ISO 4437-4:2015

1   Scope This part of ISO 4437 specifies the characteristics of valves made from polyethylene (PE) 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 4437-3:2014, and ISO 4437-5, it is applicable to PE valves, their joints, and to 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 MRS divided by the C factor and taking into account RCP requirements; 
   
   
     
       b)  temperature of 20 °C as reference temperature; 
     
       
         NOTE 1  For other operating temperatures, derating coefficients are given in [ISO 4437-5:2014](/catalog/ISO%204437-5%3A2014). 
     
   
   
     
       c)  operating temperature between −20 °C and +40 °C. 
   
 

This International Standard covers a range of maximum operating pressures and gives requirements concerning colours and additives.

   NOTE 2  It is the responsibility of the purchaser or specifier to make the appropriate selections from these aspects, taking into account their particular requir...