Individual test run of screw pump

If the manufacturer has the accompanying documents, why can’t they take a look themselves?

This post was last edited by Zhongheng Pump Industry on 2020-3-20 at 10:20. Hello, original poster! Please confirm how many screws there are. Single-screw pumps, twin-screw pumps, and triple-screw pumps are all different from each other. Please specify.

1. First of all, you must understand the working principle of screw pumps. Screw pumps are not centrifugal pumps; rather, they are positive-displacement pumps. Without backpressure, its pressure can’t rise. II. The principle of a screw pump is to transport materials through the compression of screws; there is a gap between the screws, and certain requirements exist regarding the viscosity of the materials. If the viscosity is too low, the outlet valve of the pump closes, resulting in low pressure at the pump’s outlet. III. Ensure that the viscosity of the medium meets the required standards; if the outlet valve is closed during testing, it will cause the pressure at the outlet of the screw pump to become excessively high, thereby damaging the pump. Therefore, pumps are equipped with pressure relief valves, and the outlet valve must not be closed when starting or operating the pump under normal conditions.

Commissioning and Acceptance of Screw Pumps 4.1 Preparations before Commissioning 4.1.1 Check the maintenance records to ensure they meet quality requirements. 4.1.2 The quality and quantity of lubricating oil in the bearing housings must be satisfactory. 4.1.3 The seal and cooling water pipes must not be blocked or leaking. 4.1.4 Check the rotation direction of the motor. 4.1.5 The pump should rotate smoothly without any abnormal noises. 4.1.6 It is necessary to fill the pump with the liquid to be transported. 4.1.7 The inlet and outlet valves should be opened to at least 30% of their full opening. 4.2 Commissioning 4.2.1 Screw pumps must not be tested under no-load conditions. 4.2.2 When operating properly, the following mechanical performance and operational parameters must be met: a. Smooth operation without any abnormal noises. b. Vibration levels must comply with the requirements specified in SHS 01003 2004 (Standards for Vibration in Rotating Machinery in the Petrochemical Industry). c. The cooling water and oil systems must function properly without any leaks. d. Flow rate and pressure must remain stable. e. Bearing temperature rises must meet relevant standards. f. Current levels must not exceed the rated values. g. Sealing leakage must not exceed the following limits: For mechanical seals used with heavy oils, the leakage rate must not exceed 5 drops per minute； For light oil, the rate should not exceed 10 drops per minute; for filler-sealed heavy oil, the rate should also not exceed 10 drops per minute ； The flow rate of light oil should not exceed 20 drops per minute. 4.2.3 The backflow from the safety valve should not last more than 3 minutes. 4.2.4 After 24 hours of testing and confirmation that everything is satisfactory, the acceptance procedures shall be carried out as specified, after which the equipment can be put into use. 4.2.5 During the testing period, maintenance and inspection personnel should increase the frequency of their inspections. 4.2.6 The outlet valve must not be closed first when stopping the equipment. 4.3 Acceptance: 4.3.1 The quality of the maintenance work must meet the requirements specified in SHS 01001–2004 (Standards for the Condition of Petrochemical Equipment); the maintenance records must be complete and accurate, and in compliance with the requirements of these regulations. 4.3.2 The technical specifications of the equipment must meet the design requirements or be sufficient to meet production needs. 4.3.3 The condition of the equipment must meet the standards for being in good working order. Thank you to Baidu