1. The medium used shall be similar to water, with kinematic viscosity of less than 150mm2 / s, no hard particles and no corrosive properties; 2. The environmental altitude of multistage centrifugal pump shall be less than 1000m, which shall be put forward in order when exceeding, so that our factory can provide you with more reliable products; 3. The medium use temperature shall be - 15 ℃ ~ 120 ℃; 4. The system working pressure shall be ≤ 2.5MPa; 5. The ambient temperature shall be lower than 40 ℃, The relative humidity is less than 95%.