coupling 1) Material:stainless steel 2) Standard:ISO,DIN,JIS,GB ... ,JIS,ANSI/ASME,GB/T12459,GB/TCertificateCE,ISOSurfacerust-proof oil,black painted,vanish,galvnanizing and as per customer requirementApplicationtransportation,lining,petroleum ... ,metallurgy,construction,water conservancyPackageseaworthy packing and as per customer requirement coupling