NIB-SEAL on sweat ball valves are shipped unassembled.

在球上，NIB-SEAL在装时处于未组装状态。

The condensability of liquid,the Westphal's effect and the continuous flow condition are not only comprehensively considered,but also the dynamic property of the ball valve being established.

结合现场试验,根据直线电机采油泵特性,综合考虑了液体可压缩性、魏氏效应、液体连续流条件和球力特性,建立了直线电机采油泵球规律精确微分方程组。