A peristaltic pump system consists of three main components: the pump head, the tubing, and the drive unit.
I. Pump Head Selection
1. Pump heads are available in single-channel and multi-channel configurations for fluid transfer.
2. Tubing should be easy to replace.
3. The design should facilitate secure tubing fixation.
4. Fine-tuning mechanisms (such as ratchets) allow for adjustment of the compression gap to accommodate tubing of varying wall thicknesses.
5. Roller selection: A 6-roller design yields slightly higher flow rates; a 10-roller design results in reduced fluid pulsation amplitude.
II. Tubing Selection
1. Factors for selecting peristaltic pump tubing:
a. Good elasticity (ability to quickly regain shape after compression)
b. Good wear resistance
c. Sufficient pressure-bearing capacity
d. Good airtightness (leak-proof)
e. Good temperature resistance, low adsorption, resistance to swelling and aging, strong corrosion resistance, low extractables, etc.
2. Tubing parameters: Wall thickness and inner diameter are the primary specifications.
3. Tubing materials: Rubber, plastic, silicone rubber, synthetic materials, etc.; different materials offer varying performance characteristics and suit different applications.
4. Considerations when selecting tubing:
a. Chemical corrosion resistance / chemical compatibility
b. Chemical compatibility refers to the tubing maintaining excellent chemical performance when transporting specific fluids (e.g., good temperature resistance, resistance to aging/swelling/corrosion, low adsorption, low extractables).
c. Chemical corrosion resistance decreases as temperature rises; chemicals that have no effect on the tubing at room temperature may affect it at higher temperatures.
d. Pressure resistance: The pressure-handling capability of the tubing limits the application of the peristaltic pump.
e. Temperature: Users must consider the tubing's operating temperature range, as different materials exhibit varying temperature performance characteristics.
f. Dimensions: Tubing dimensions directly affect flow rate; wall thickness and inner diameter should be considered during pump design to select the optimal size. The inner diameter determines the flow rate, while the wall thickness determines the tubing's ability to compress and rebound, significantly influencing its service life.
g. Certification: Tubing intended for specific applications should meet the relevant certification standards.
h. Tubing service life/flexibility/elasticity: Service life varies depending on the tubing type, material, pump head, and operating speed; consequently, different types of tubing offer varying levels of resistance to repeated roller compression and friction.
III. Drive Selection
When selecting a peristaltic pump drive, the primary considerations are flow rate requirements, control precision, and the application environment. First, determine the drive's speed range and required power based on the target flow rate, ensuring compatibility with the selected pump head. Second, select the control type based on operational needs: choose a basic variable-speed drive for simple fluid transfer, or a flow-controlled or dispensing drive for applications requiring precise metering or dispensing.