1.CONSTAB PEX,Al raw material 2.AENOR,WATERMARK,EME,ISO Certificates ... the world2.With WATERMARK,AENOR,EME,ISO certificates verify,PEX AL PEX pipe is widely used for underfloor heating.TÜV ... have perfect quality control management system.4.Butt-welded PEX AL PEX pipe is made of 5layers,both inner and outer ... layers are pex,Aluminium in the middle,and two layers of ...