It is equipped with asphalt return tube, anti-puffing pressure vent valve, anti-aging overhead nitrogen valve, thermometer, volumeter and output asphalt rapid discharge valve and coupling.

配备沥青溢流管、防冒液呼吸阀、防老化顶置充氮阀、温度计、容量计和输出沥青的快速卸料阀及接耦。

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Intercept the fluid medium upstream of the valve to be inspected with a shut-off valve and ensure that the subject valve is not under pressure (vent downstream, if necessary).

截取阀门上游的流体介质，用一个关闭阀门来进行检测，确保相关的阀门不处在压力下(如果必要的话，排除下游的流体介质)。

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Relief valve or vent valves permit a small pressure to be maintained on the vapor over the oil in the tank (except when the tank is being emptied).

卸压阀或通气阀使罐内油面上方的蒸汽保持微正压(油罐正在排空时除外)。

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These valves use a screw type valve instead of a simple flap, and they have a pressure regulating mechanism that will vent water to the ground if the intake pressure exceeds a set level.

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