We will consider these types of pumps:
- PUMP WITH GEARS – Internal / External (crescent-shaped)
- PUMP WITH LOBES (Single, multiple)
- Worm screw pump – Progressive cavity
- PUMP WITH PADDLES – Unbalanced
PUMP WITH GEARS – Internal / External (crescent-shaped)
Dry-running not possible, rotating gears and minimal tolerances of the parts in contact with the fluid, relief or bypass valve necessary, cannot transfer abrasive fluids, limited capacity of managing variable, thixotropic or Non-Newtonian viscosity.
What is a thixotropic fluid?
Thixotropy is the property of certain fluids that change their viscosity when they undergo shear stresses or long periods of rest or peristaltic movements. In these conditions, the fluid can change from the pasty, almost solid, grease state to the liquid state or, more in general, from a gel to a liquid, for example: Ketchup, margarine.
What is a non-Newtonian fluid?
A non-Newtonian fluid (or also amorphous fluid) is a fluid whose viscosity varies based on the shear stress applied. Consequently, non-Newtonian fluids have not a set viscosity value. Many polymeric solutions are non-Newtonian fluids.
The AODD Pump?
Dry-running possible, there are no rotating gears and minimal tolerances of the parts in contact with the fluid, does not require a relief or bypass valve, can transfer abrasive fluids, designed to manage different types of flow, viscosity and head.
PUMP WITH LOBES (Single, multiple)
Limited suction capacity, rotating gears and minimal tolerances of the parts in contact with the fluid, relief or bypass valve necessary, cannot transfer abrasive fluids, cannot transfer fluids containing suspended solids.
The AODD Pump?
Dry-running suction capacity up to about 6 meters (depending on the configuration of the materials), there are no rotating gears and minimal tolerances of the parts in contact with the fluid, relief or bypass valve not necessary, can transfer abrasive fluids, can transfer fluids containing suspended solids.
WORM SCREW PUMP – Progressive cavity
Dry running not possible. Rotating gears and minimal tolerances of the parts in contact with the fluid, very expensive parts, relief or bypass valve necessary, cannot transfer abrasive fluids, costly repairs in terms of time, labour and spare parts – only possible off-line, installation requires a lot of space and a solid support base, the screw can slide with water or not very viscous liquids.
The AODD Pump?
Dry-running possible without problems, not very costly spare parts, does not require a relief or bypass valve, can transfer abrasive fluids, fast and not very costly repairs can be carried out directly on the system, installation doesn’t require a lot of space or a support base, the operation is not compromised by pumping water or not very viscous liquids.
PUMP WITH PADDLES – Unbalanced
Limited dry-running capacity, rotating gears and minimal tolerances of the parts in contact with the fluid, relief or bypass valve necessary, cannot transfer abrasive fluids, limited capacity for transferring fluids containing suspended solids, quick wear of the paddles.
The AODD Pump?
Dry-running possible without problems, no rotating gears and minimal tolerances of the parts in contact with the fluid, does not require a relief or bypass valve, can transfer abrasive fluids and can transfer fluids containing suspended solids.
So… What do you think? It is time to replace your pump with an air operated double diaphragm pump.
Debem will surely be your best choice.
