Regarding the pressure rating of threaded pipe fittings
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I would like to ask about the pressure rating standards for pipe fittings. ASME B16.11, which is part of the American standards, is a standard for forged threaded and socketed pipe fittings. It specifies three grade standards for threaded pipe fittings: 2000lb, 3000lb, and 6000lb, corresponding respectively to Sch80, Sch160, and XXS. Although the standards allow for a combination of different grades and wall thicknesses for piping fittings, I would still like to ask whether there is a corresponding pressure grade for threaded fittings that matches Sch40 pipes Which standard should be looked up?
NOTE: (1) This Table is not intended to restrict the use of pipe of thinner or thicker wall with fittings. The pipe actually used may be thinner or thicker in nominal wall than that shown in Table 7. When thinner pipe is used, its strength may govern the rating. When thicker pipe is used (e.g., for mechanical strength), the strength of the fitting governs the rating. When using thinner pipes, it is their strength that determines the pressure rating. At the same time, check whether the thread machining depth has reached the wall thickness of the tube, which could cause the tube to be cut in half.
In practice, we usually use Sch40 pipes, and for fittings, we commonly purchase B16.11 threaded fittings; however, the lowest price is 3000. In reality, our operating conditions don’t require such a high level. Are there any more comprehensive standards for threaded pipe fittings, either domestically or internationally? There is no issue with machining threads for Sch40.