Electrical Conduit/Electrical Pipe/Electrical TubeElectrical Conduit/Electrical Pipe/Electrical Tube: Outer diameter:21.3-219mm Standard: BS, JIS, GB, ... ,metallurgy,shipbuilding,constructio,etc.SEAMLESS pipe : ISO 9001CERTIFICATE. BUTT WELDED FITTING: Production acc. to the standard of GB /ASTM / ASME / DIN ...