Solution

All newly purchased and installed centrifugal pumps shall undergo a test run after installation. The test run shall be carried out in accordance with the following procedures and precautions.

1. No dry running or no-load test run is permitted before starting the centrifugal pump. A liquid-loaded test run shall be performed in line with the operating procedures specified in the pump manual. For pumps with a forced lubrication system, the temperature rise of the bearing oil shall not exceed 28°C, and the bearing metal temperature shall be less than 93°C.

2. For centrifugal pumps with oil-ring lubrication or splash lubrication systems, the lubricating oil temperature shall not exceed 39°C, and the bearing component temperature shall be less than 82°C.

3. During the test run, check the vibration value of the centrifugal pump bearings. The vibration standards for centrifugal pump bearings may refer to relevant vibration specifications for petrochemical rotating machinery.

4. During the test run, the centrifugal pump shall operate smoothly and quietly. The cooling and lubricating oil systems shall function normally, and no leakage shall occur in the pump and its auxiliary pipelines.

5. During the test run, monitor whether the motor current is within the specified range. If overcurrent occurs, it indicates that the actual operating head is lower than the pump’s rated head. In this case, partially close the discharge valve to control the flow rate and bring the current within the rated range.

6. Leakage from various seals and media in centrifugal pumps shall not exceed the following standards:

(1) Centrifugal pumps for clean water with mechanical seals:

Light oil: 10 drops/min; Heavy oil: 5 drops/min

(2) Multistage centrifugal pumps with packing seals:

Light oil: 20 drops/min; Heavy oil: 10 drops/min

(3) For magnetic drive pumps handling toxic, harmful, flammable or explosive media, no visible leakage is allowed.