多级泵必须满足介质特性的要求。

  （1）对输送易燃、易爆有毒或贵重介质的泵，要求轴封可靠或采用无泄漏泵，如磁力泵（无轴封，采用隔离式磁力间接驱动）；

  （2）对输送腐蚀性介质的多级泵，要求对流部件采用耐腐蚀性材料。如氟塑料耐腐蚀泵；

  （3）对输送含固体颗粒介质的多级泵，要求对流部件采用耐磨材料，必要时轴封用采用清洁液体冲洗。

   3、机械方面要求多级泵可靠性高、噪声低、振动小。

   4、正确计算多级泵采购的投入成本，包括采购成本和安装维护成本。

Multistage pumps must meet the requirements of medium characteristics.

(1) For pumps transporting inflammable, explosive, toxic or precious media, reliable shaft seals or leak-free pumps are required, such as magnetic pumps (without shaft seals, driven indirectly by isolated magnetic force);

(2) For multi-stage pumps transporting corrosive media, the convective components are required to be made of corrosion-resistant materials. For example, fluoroplastics corrosion resistant pump;

(3) For multi-stage pumps containing solid particles, wear-resistant materials are required for convection parts, and cleaning liquid is used for shaft seals when necessary.

3. In mechanical aspect, multi-stage pumps are required to have high reliability, low noise and low vibration.

4. Calculate the input cost of multi-stage pump purchase correctly, including purchase cost and installation and maintenance cost.