动背压和静背压怎么翻译? i. back pressure is the pressure that exists at the outlet of a pressure relief device as a result of the pressure in the discharge system. it is the sum of the superimposed and built-up back pressures. j. built-up back pressure is the increase in pressure at the outlet of a pressure relief device that develops as a result of flow after the pressure relief device opens. k. superimposed back pressure is the static pressure that exists at the outlet of a pressure relief device at the time the device is required to operate. it is the result of pressure in the discharge system coming from other sources and may be constant or variable. 自api 520。 查看更多