The development of bags has resulted in a wide variety of types today, among which we commonly see backpacks, briefcases, cosmetic bags, ice bags, schoolbags, wallets, belt bags, pen cases, CD bags, and so on. Our company specializes in making wallets, which include short wallets, long wallets, hinge wallets, zipper wallets, shredded silver bags, key bags, etc. The short wallets are further categorized into horizontal or upright single bags, mother-child bags, flip-top bags, and triple-fold bags. The main materials used in making wallets include various genuine leather, artificial leather, nylon, etc.Bag Pattern Knowledge and Methods

API is the abbreviated English name for the American Petroleum Institute, commonly referred to as API standards.API Standard Lecture Notes

This standard specifies the inspection and pressure test requirements. This standard applies to the inspection and pressure test of metal sealing pairs, elastic sealing pairs, and non-metallic sealing pairs (such as ceramics) for valves, including their , , , and . After the agreement of both parties, it can also be applied to other types of valves. Valve Inspection Standards