API Petroleum Casing The standard of api petroleum casing is api5l is the American Petroleum Institute standards, general petroleum casing export standards are based on this, so it is called api petroleum casing, api petroleum casing in accordance with the material points mainly k55 petroleum casing, j55 petroleum casing, n80 petroleum casing, p110 petroleum casing, etc., petroleum casing buckle including short round buckle (stc), long round buckle (ltc), partial trapezoidal (btc) the most important and most common on these three kinds of buckle, in addition to airtight buckle, threaded buckle and other special buckle. (ltc), partial trapezoidal (btc) the most important and most common on these three, in addition to airtight buckle, threaded buckle and other special buckle shape. api oil casing main production base in north China, oil casing can be divided into seamless and welded pipe, the price of seamless pipe than the welded pipe is expensive, oil casing material than the…