51吃瓜

??? ???? ??? ?? ??? ???? ???? ??? ????? ???? ????? ?? ? ????? ???? ??????? ?? ????? ??? ?????? ????? ????.

????? ???? ???

pumps petroleum are classified based on their stable oil discharge capacity, which means that the maximum pressure must be limited by a pressure reducing valve. ??? ???? ???? ???? ??????? ???? ???? ????? ?? ??? ?????? ???? ??????? ?? ???? ??? ???? ???? ????? ???.

???? ???? ???? ??? ?? ?? ??? ?? ??? ? ?? ???? ???? ????? ??? ???. ???? ????? ?? ???? ????? ????? ??? ? ?? ????? ???? ??????? ??? ???. ???? ???? ???? ???? ?? ???? ????? ?????? ??????? ???? ???? ??? ??? ??????. ?? ??? ????? ???? ????? ?? ??? ????? ???? ?? ??? ?? ???? ?? ?????? ?? ??? ????? ?? ???? ???? ?? ??? ???. ?? ???? ???? ????? ???? ???? ?? ??? ??? ???? ???? ??????? ??????? ???? ??????? ???? ???? ??? ???????? ????? ???. ??? ??????? ???? ?????? ???? ???? ??? ?? ?? ???? ???? ?????? ????? ???. ??? ????? ???? pump ?????? ??????

????? ?? ???? ????????? ???? ?? ???? ??? ????? ?? ????? ?? ????:

1. ???? ???? ??? ? ???? ??? ?? ???? ???? ?????? ??????;

2. ???????? ????? ????? ???????? ????? ????? ???? ?????

3. ??????? ??? ??? ? ?????????? ???????? ???? ?????? ???? ??? ?? ??????? ???. ???? ??????? ?? ??? ????? ???? ????? ????? ????.