1.See there is no manufacturing license, mainly to see whether the cylinder or shield has a license number, the name of the gas filled, product standard number, actual weight, actual volume and some seal marks, but also to see a product certificate and quality certificate.
2.the coating of the cylinder surface is uniformly uniform, there are no bubbles, flow marks, peeling defects, etc. for the bottle body, mainly to see there is no cracks, damage, the welding site has no cracks, pores, slag clamping, bite edges and other defects, in addition, also to see the bottle seat, bottle valve thread, such as whether there are damage, if there are such problems, can not be used.
3.The gas tightness of the cylinder can be detected, so as to observe the leakage of the valve orifice and stem, if there is leakage, it is not possible to use.
4.the weight of the cylinder is also very important, if the weight is too light or too heavy, all indicate that there is a problem, can not be used.