KNOLL gear pumpThey are self-priming and can be dry lifted, although their starting characteristics are improved if the gears are wetted. Gears need to be lubricated by pumped fluid and should not idle for long periods of time. For example, some gear pump designs can operate in either direction, so the same pump can be used to load and unload containers.

The tight tolerances between gear and housing mean that these types of pumps are prone to wear, especially when used with abrasive fluids or feeds containing entrainment solids. However, some designs of gear pumps, especially internal variants, allow handling of solids. External gear pumps have four bearings in the pumping medium and have very small tolerances, making them less suitable for handling abrasive fluids. With only one bearing (and sometimes two) operating in the fluid, internal gear pumps are more robust. Gear pumps should always have a filter on the suction side to protect them from large, potentially damaging solids.

In general, if the pump is dealing with abrasive solids, it is recommended to choose a pump with a larger capacity so that it can operate at a lower speed to reduce wear. However, it should be remembered that the volumetric efficiency of the gear pump is reduced at lower speeds and flow rates. The gear pump should not be run far from its recommended speed.

For high temperature applications, it is important to ensure that the operating temperature range is compatible with the pump specifications. Thermal expansion of the housing and gears reduces the clearance within the pump, which can also lead to increased wear and, in extreme cases, pump failure.

Despite taking the best precautions, gear pumps often suffer wear and tear on gears, housings and bearings over time. As the clearance increases, the efficiency gradually decreases and the flow slip increases: the pumped fluid leaks from the discharge port back to the suction side. The flow slip is proportional to the cube of the clearance between the gear teeth and the casing, so in practice the effect of wear is minimal until a critical point is reached and performance rapidly declines.

The gear pump continues to pump at back pressure, and if it is blocked downstream, it will continue to pressurize the system until the pump, pipe, or other equipment fails. Although most gear pumps are equipped with relief valves for this reason, it is always recommended to install relief valves elsewhere in the system to protect downstream equipment.

Internal gear pumps operate at low speeds and are usually preferred for shearing sensitive liquids such as food, paint and soap. The higher speed and lower clearance of the external gear design make it unsuitable for these applications. When hygiene is important, internal gear pumps are also preferred because they are mechanically simple and easy to disassemble, clean and reassemble.

The above describes what the limitations of the KNOLL gear pump are. In addition, Shenzhen Oudejie Technology specializes in selling new original German imported KNOLL gear pump, and promises to sell products are new original imported, while providing our customers with quotation, selection, product information and other services.