Introduction to the factors affecting the life of peristaltic pump hoses

The peristaltic pump hose is the main working component of the peristaltic pump, and its performance directly affects the accuracy and stability of the peristaltic pump flow. As a flexible moving part, the hose is a part that has a certain service life and needs to be replaced regularly.

There are many factors that affect the life of a peristaltic pump hose. The main factors are the running speed of the pump head, the material of the hose, and the pressure tube gap between the pump head roller and the arc.

The damage of the hose is mainly caused by fatigue damage. Therefore, the operating speed of the pump head has a very large effect on the life of the hose. For example, if the pump head is running at 600 rpm, if the actual test life of the hose is 200 hours, then the operating life of the pump head can be reduced to 300 rpm, and the hose can have a service life of at least 400 hours. Therefore, when selecting a peristaltic pump, the pump head with a large flow rate should be selected as much as possible, so that the required flow rate can be achieved at a lower speed, and the service life of the hose can be maximized.

The material of the hose has a very large effect on the life of the hose. Different hose materials have a very long life span under the same operating conditions. The domestically produced hose is generally a food grade silicone tube, and the universally calibrated life is 200 hours (uninterrupted operation at 600 rpm); under the same conditions, the imported long-life hose can easily reach more than 1200 hours. Of course, the price of imported hoses will be much higher than that of domestic hoses. It is necessary to determine whether it is necessary to use imported hoses according to actual use. It should also be noted that not all imported hoses have a long service life. The inlet life of some materials may be much shorter than that of domestic hoses. It is only suitable for some special occasions.

Let's talk about the effect of the pressure tube gap between the roller head and the arc of the peristaltic pump on the life of the hose. Our company has done a comparative experiment in this aspect, the pressure of one of the pump heads is increased to 0.3Mpa, and the pressure of the other pump head is 0.15Mpa. The result is a hose life of 280 hours at 600 rpm with a pressure of 0.15Mpa. The 0.3Mpa pump head has a hose life of only 50 hours. It follows that the effect of the pressure tube gap on the life of the hose is very large. Because the damage of the hose is mainly caused by fatigue damage, the pressure gap is small, the pump head squeezes the hose, and the hose is more likely to cause fatigue damage. Of course, the outlet pressure of the pump head is larger. . Our peristaltic pump heads are pressure-adjustable and can be adjusted to the appropriate outlet pressure for different occasions to achieve a balance of pressure and life.

Factors affecting the life of a peristaltic pump hose. In addition to the size of the pressure tube gap, the uniformity of the pressure tube gap is also considered. For example, whether the curve of the arc is uniform, the processing error of the roller and the wheel, and the assembly error of the center of the roller and the center of the arc. The above example is to adjust the pump head to 0.3Mpa and 0.15Mpa respectively. Although the pressure value is doubled, the pressure tube gap is only less than 0.3mm, so the small dimensional error or assembly error will be seriously reduced. The service life of the hose. This is because if the pressure tube gap is not uniform, in order to ensure the airtightness of the pump head, the position at the minimum pressure will not be leaked, so that the rest will be overpressured (the gap is smaller than the normal value). This will reduce the local life of the hose.

Finally, two small methods of how to determine whether the pressure tube gap is uniform are introduced. Method 1: Run the peristaltic pump at 100 rpm and connect a barometer at the hose outlet (the full scale should not be too large, generally 0.6 Mpa maximum). When the pressure is stable, the pump speed is reduced to 1 rpm. Start and stop the peristaltic pump, so that one of the rollers stops at each position of the arc and stays for a period of time. Observe whether the barometer has a decrease in air pressure during the operation of the pump head, and the minimum is reduced to the number of indications. Generally, if the pump head is measured at 100 rpm and the air pressure is 0.15 MPa, the lowest point pressure should not be lower than 0.1 MPa. Method 2: Run a peristaltic pump at 100 rpm and record the pressure value. Then, increase the pump speed to 600 rpm, observe and record the pressure value again, and compare the pressure difference between the two pressures to determine whether the pressure tube gap is uniform. In the most ideal case, 600 rpm is also slightly higher than the pressure at 100 rpm. Because the speed is high, the pump head will slightly increase the pressure of the system because it is too late to leak gas. If the pump head is measured at 100 rpm and the air pressure is 0.15 MPa, then at 600 rpm, the pressure should be maintained within 0.18 MPa.