Should I choose a pump tube with a mechanical seal or a seal-less pump tube?
When selecting a Pump tube, the correct seal type depends primarily on the properties of the pumped medium. The decisive factor is whether the medium is prone to deposits, crystallisation, sticking or hardening.
Pump tube with mechanical seal (GLRD)
Pump tubes with mechanical seals are the preferred choice when pumping media that are prone to crystallisation, sticking, hardening or spoilage. The mechanical seal prevents the pumped medium from entering the shaft guide tube. This reduces the risk of deposits and prevents the Drive shaft from seizing.
A further advantage is the simplified cleaning and flushing of the pump tube, particularly with demanding or changing media.
During operation, a thin lubricating film formed from the pumped medium develops between the sliding surfaces of the Mechanical seal. For this reason, dry running must be avoided at all costs, as this can lead to rapid wear or damage to the seal.
Recommended for:
- crystallising media
- sticky or hardening liquids
- perishable pumped media
- applications with increased cleaning and flushing requirements
Seal-less pump tube (DL)
Seal-less Pump tubes are suitable for all applications where the pumped medium does not cause critical deposits or scaling. As there is no mechanical seal, these pump tubes have a simpler design and are less sensitive to brief periods of dry running.
Brief dry running does not usually cause immediate damage to the pump tube. Nevertheless, dry running should always be avoided to prevent unnecessary wear and to maximise the Pump’s service life. Operation should therefore always be supervised.
Recommended for:
- non-critical, clean or low-viscosity media
- Applications with no tendency to form deposits
- Applications with the possibility of short-term dry running
Conclusion:
If the pumped medium is prone to crystallisation, sticking, hardening or spoilage, a pump tube with a mechanical seal should generally be used. In all other standard pumping applications, a seal-less pump tube is usually the appropriate choice.