When selecting a fluoroplastic self-priming pump, customers should consider the following aspects to ensure the right choice:
1. Viscosity: The viscosity of the medium significantly affects pump performance. As viscosity increases, the pump's head curve drops; the head and flow rate at the optimal operating point decrease, while power consumption rises, resulting in lower efficiency. Standard catalog specifications usually reflect performance when pumping clear water; conversions are necessary when handling viscous media (correction factors for different viscosities can be found in relevant charts). For transporting high-viscosity slurries, pastes, or thick liquids, a slurry pump is recommended; our company’s UHB-ZK corrosion- and wear-resistant slurry pump is suitable for corrosive media that are viscous or contain particles.
2. Corrosion resistance: Corrosion has long been a major headache for chemical equipment. Even slight negligence can lead to equipment damage or, in severe cases, accidents. Statistics indicate that approximately 60% of chemical equipment failures are caused by corrosion; therefore, the scientific selection of materials is paramount when choosing chemical pumps. A common misconception is that stainless steel is a "universal material" suitable for any medium or environmental condition—a belief that is quite dangerous. In reality, many strong acids and alkalis commonly used in the chemical industry are highly corrosive to materials. While it is impossible to detail every instance here, the key takeaway is to avoid arbitrary or blind material selection; instead, consult relevant technical data and draw upon established industry experience.
3. Sealing: Zero leakage is the ultimate goal for chemical equipment, a requirement that has driven the expanding application of magnetic drive pumps. However, achieving true zero-leakage performance remains a challenge, with issues such as the service life of the magnetic isolation shell, material pitting, and the reliability of static seals still requiring attention. To ensure the correct operation and use of fluoroplastic self-priming pumps, users must adhere to the following guidelines:
First, the pump's trial run must meet these requirements:
① The direction of rotation of the driver must match that of the pump;
② Verify the rotation direction for both pipeline pumps and close-coupled pumps;
③ Ensure all fixed connections are secure, and that the type and quantity of lubricant applied to lubrication points comply with the equipment's technical specifications;
④ Perform pre-lubrication on components requiring it, in accordance with regulations;
⑤ Ensure all indicating instruments and safety protection devices are responsive, accurate, and reliable;
⑥ Ensure the rotor turns freely and smoothly, without any abnormalities;
⑦ For high-temperature pumps, preheat the pump casing before the trial run; the temperature must rise uniformly at a rate not exceeding 50°C per hour, and the temperature difference between the pump casing surface and the process piping at the working medium inlet must not exceed 40°C;
⑧ Install connection devices to accommodate thermal expansion, and set up bypass connections to supply cooling water.
Second, observe the following points during the operation of fluoroplastic self-priming pumps:
① Do not operate without liquid; do not adjust the suction inlet to reduce discharge; avoid operation at excessively low flow rates;
② Monitor the operation closely; completely prevent leakage from the stuffing box, and use new packing material when replacing it;
③ Ensure an adequate flush water flow for the mechanical seal; do not use excessive water flow for water-cooled bearings;
④ Do not over-lubricate;
⑤ Perform inspections according to the recommended schedule. Maintain operational records, including running hours, details on packing adjustments and replacements, lubricant additions, and the timing of other maintenance activities. Regularly measure and record pump suction and discharge pressures, flow rate, input power, temperatures (of the flushing fluid and bearings), and vibration levels.
⑥ The main pump unit relies on atmospheric pressure to lift water from a lower level to a higher one; since atmospheric pressure can support a water column of only about 10.3 meters, the pump unit cannot operate if positioned 12 meters above the water surface.
Selection and usage precautions for fluoroplastic self-priming pumps