... displacement, degree of axial stretching problems.The material can be made according to different acid, alkali, corrosion ... and maintenance, long life, but to avoid contact with sharp metal instruments, so as not to puncture the ... 1999 or GB/T12777-2008 national standardmaterialcarbon steel , stainless steel , alloy steel , low-temperature steel certificationISO9001:2000 Features large amount of ...