In circle triangle expression liquid flow direction, if the triangle acme outward, showed the liquid flow outputs outward, expressed this is an oil pump.

圆圈中的三角形表示液流方向，如果三角形尖端向外，说明液流向外输出，表示这是油泵。

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Note: the reason why a flow arrow was not used was for applications such as pump isolation whereas preferred sealing direction and the high pressure side are not necessarily the same.

注意：不采用流向箭头的原因是，在某些应用场合，如泵隔离，其优先密封方向和高压面并一定相同。

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