Pump tube PVDF

When selecting the appropriate drive type for a Pump tube, the question often arises in practice as to whether an impeller or a rotor should be used. The decision depends largely on the hydraulic requirements of the specific application.

Application 1: High delivery pressure and greater delivery heads required

Requirement
If long hose or pipe runs need to be overcome, the fluid has increased Viscosity or density, or higher overall pressure losses occur, a greater delivery head is required.

Typical influencing factors are:

• Long hose lengths
• Viscous or heavy fluids
• Required pressure build-up in the system

Recommended solution
Impeller (L) = Radial impeller

The impeller is designed for applications where a stable pressure build-up is required. The pump tube thus enables reliable delivery even with increased resistance in the system and ensures a constant delivery capacity under demanding operating conditions.

Application 2: High flow rate with free discharge

Requirement
Where there is a free discharge and no significant Pressure losses in the delivery system, the priority is often to achieve the highest possible flow rate.

Typical influencing factors are:

• Short hose lengths
• Low flow resistance
• Focus on flow rate rather than delivery head

Recommended solution
Rotor (R) = Axial impeller

The rotor is designed for maximum flow rates at minimum back pressure. It is ideal for applications with a free outlet where large flow rates need to be delivered efficiently and economically.

Conclusion:
The choice between an impeller and a rotor depends primarily on the hydraulic requirements of the application. For higher pressure requirements and greater delivery heads, the impeller is the appropriate solution. For free discharge and where high flow rates are required, the rotor is recommended.

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.