German ETP pump ETP model ETP price

ETP pumps are rotary pumps that transport liquids or increase their pressure by relying on the change and movement of the working volume formed between the pump cylinder and the meshing gears. Two enclosed spaces are formed by two gears, the pump body, and the front and rear covers. When the gears rotate, the volume of the space on the disengaging side increases from small to large, creating a vacuum that draws in the liquid, while the volume of the space on the meshing side decreases from large to small, squeezing the liquid into the pipeline. The suction chamber and the discharge chamber are separated by the meshing line of the two gears. The pressure at the discharge port of a gear pump depends entirely on the magnitude of the resistance at the pump outlet.

ETP pump operating principle

The concept of a gear pump is very simple. Its most basic form consists of two gears of identical size meshing and rotating within a closely fitted housing. The interior of this housing resembles a "8" shape, with the two gears installed inside; the outer diameter of the gears and their sides fit closely with the housing. Material from the extruder enters between the two gears at the suction inlet and fills this space. As the teeth rotate, the material moves along the housing and is finally discharged when the teeth mesh. Gear pumps are also known as positive displacement devices. Like a piston in a cylinder, when one tooth enters the fluid space of another tooth, the liquid and the tooth cannot occupy the same space simultaneously because the liquid is incompressible; thus, the liquid is mechanically squeezed out. Due to the continuous meshing of the teeth, this phenomenon occurs continuously, providing a continuous discharge volume at the pump outlet. With each revolution of the pump, the discharged volume remains the same. As the drive shaft rotates uninterrupted, the pump discharges fluid without interruption. The pump's flow rate is directly related to its rotational speed. In practice, there is a small amount of fluid loss within the pump because this fluid is used to lubricate the bearings and the sides of the gears, and the pump body cannot have a gap-free fit. Therefore, the fluid cannot be discharged from the outlet 100%, making some fluid loss inevitable. This prevents the pump's operating efficiency from reaching 100%. However, the pump can still operate well, achieving an efficiency of 93% to 98% for most extruded materials. This type of pump is not significantly affected by changes in the viscosity or density of the fluid in the process. If there is a damper, such as a filter screen or a restrictor placed on the discharge side, the pump will push the fluid through them. If this damper changes during operation—i.e., if the filter becomes dirty or clogged, or if the back pressure of the restrictor increases—the pump will maintain a constant flow rate until it reaches the mechanical limit of the weakest component in the system (a torque limiter is usually installed). There is actually a limit to the rotational speed of a pump, which mainly depends on the process fluid. If oil is being transported, the pump can rotate at high speeds, but this limit increases significantly when the fluid is a high-viscosity polymer melt. It is crucial to fill the space between the two teeth on the suction inlet side with high-viscosity fluid. If this space is not completely filled, the pump cannot discharge an accurate flow rate. Therefore, the PV value (pressure × flow velocity) is another limiting factor and a process variable. Due to these limitations, gear pump manufacturers offer a range of products with different specifications and displacements (volume discharged per revolution). These pumps are matched to specific application processes to optimize system capacity and price.

ETP pump usage precautions

Gear pumps are suitable for various industries and handle a wide range of media. These gear pumps offer advantages such as robust structure, easy installation, easy disassembly, simple maintenance, uniform and continuous flow, slight wear, and long service life. 1) During the use of gear pumps, frequent greasing is required. Since grease evaporates relatively easily, attention must be paid to replenishment and replacement. Additionally, keep the bearing area clean; 2) When using or after using the electric oil pump, place it in a dry, non-corrosive, and clean environment; 3) Frequently inspect and maintain the gear pump during use. Check the electric oil drum, including the power cord, internal wiring, plug, and switch, to ensure they are functioning normally. Inspect bearing components for any damage; 4) Preserve every component of the gear pump. During disassembly and inspection, keep all parts clean and stored properly.

ETP pump maintenance

When using a gear pump, wear on the gear pump is inevitable, leading to various issues. Therefore, it is essential to master the most common maintenance techniques for gear pumps. This enables accurate diagnosis of problems. The routine maintenance techniques are as follows:1) Maintenance of the working surface: If the wear on the pump cover's working surface is minor, you can manually remove the wear marks by lapping. Place a small amount of valve grinding compound on a surface plate or thick glass plate, then lap the pump cover on it until the wear marks are removed and the working surface is flat. If the wear depth on the pump cover's working surface exceeds 2 mm, machining followed by lapping is required for repair.3) Maintenance of the drive shaft bushing bore: The repair method for wear on the drive shaft bushing bore in the pump cover is the same as that for the housing's drive shaft bushing bore. Repair of the pump housing bore: After wear occurs in the pump housing bore, it is repaired by inserting a sleeve. This involves boring out the bore to a larger size and fitting a cast iron or steel sleeve. After sleeve insertion, bore the inner cavity to the required dimensions, and grind the protruding end of the sleeve flush with the pump housing mating surface. Maintenance of the valve seat: Pressure-limiting valves come in two types: ball valves and plunger valves. After wear on the ball valve seat, place a steel ball on the valve seat and gently tap the steel ball with a metal rod until the ball valve seats tightly against the valve seat. If the valve seat is severely worn, ream to remove the wear marks, then use the above method to achieve a tight seal. After wear on the plunger valve seat, apply a small amount of valve grinding compound for lapping until a tight seal is achieved. The above describes basic component-level maintenance for gear pumps. During application, other different issues may arise, requiring careful analysis to identify the root causes of these problems.

Weidou Intelligent Technology specializes in selling German ETP manual pumps, ETP gear pumps, ETP diaphragm pumps, ETP centrifugal pumps, ETP piston pumps, ETP vacuum pumps, ETP screw pumps, ETP submersible pumps, ETP peristaltic pumps, ETP lubrication pumps, ETP vane pumps, ETP metering pumps, ETP hand pumps, ETP barrel pumps, ETP cam pumps, ETP booster pumps, ETP liquid pumps, and ETP air pumps. Original imports from Germany. Welcome inquiries and orders from users.