BUTT WELDING 18648 PUBLISHED
Iranian national standard with the number 18648 published in 1393. This standard describes polyethylene pipes and fittings Butt welding methods.
German DIN standard
Deutsches Institut für Normung (DIN) is German national standard organization built in 1917. This standard has over 30.000 technology standard. DIN website address is : http://www.din.de/en