How does Tapflo PT Peristaltic Hose Pump work?
PT Peristaltic Hose Pump is typically used for transfer applications of abrasive, viscous, solids laden and corrosive fluids where a reliable and robust pump which offers high pressure and high flow rates is required. Designed for high flow industrial transfer applications where accurate control and pressures up to 15 bar are required. We have combined the best materials with smart design solutions in order to maximise running time and minimise service intervals.
The principle of operation of the pumping action in the Tapflo PT Peristaltic Hose Pump is achieved by pinching a circular loop of rubber tube with two diametrically opposed rotating wedges. Due to the rotational movement, the fluid in the tubes is pushed ahead of each wedge. When each wedge reaches the end of the loop, the hose is released and the wedge rotates to the start of the loop to begin a new cycle.
As the wedge releases the reinforced tube, it immediately returns to its original shape, thereby ensuring positive suction and priming. This construction makes it a smart and effective choice for a wide range of pump applications.
Construction – PT Series
To protect the bearing of the gearbox against penetration of the lubricant or the pumped liquid we fit a lip seal around a hard shaft ring.
If the hose ruptures, the pumped product damages the seal instead of penetrating the gearbox. Our casting is also fitted with a Leakage Channel, which must be kept open to atmosphere.
Shoe vs Roller Design
- On many hose pumps, rollers are used to compress the hose.
- This design has proven successful in the lower pressure applications (PTL Series), since lubrication is not really necessary between the hose & roller and the radial forces are very low, allowing the rotation.
- In the higher pressure applications, from approx. 3 bar, the rollers do not rotate anymore and the angle at the point of compression becomes fairly steep which acts negatively on the hose. In this case the shoe design has proven to be more effective, since they act more gently on the hose. The PT Series is designed for higher pressure applications and is therefore supplied with shoes as standard.
- By the wave effect produce by the shoe, the particles are pushed before it and cannot be squeezed between the inside of the hose as with rollers
- To protect the hose, the shoes operate in a bath of lubricant. Depending on the application, different oil types or glycerine based fluids can be used.
Easy Wheel Dismantling
The PT Peristaltic Hose Pump Series employs a Vecobloc system which is very easy to dismantle. Done by unscrewing an Expandable Hub. Many of our competitor’s pumps have complex assemblies which means that wheel dismantling is often not possible in situ or by the customer.
Capability of the PT Peristaltic Hose Pump
|Capacity||Up to 150 m³/hr|
|Viscosity||up to 60’000 cPs|
|Fluid Temperature||Up to 135ºC|
|Differential Pressure||Up to 15 Bar|
|Max Solids Passage||Up to 30 mm|
PT Series Capacity Table (l/hr)
|Continuous Use||Intermittent Use||Occasional Use|
Minimum 1 hr Stop after 2 hrs use Maximum 1 Hr / Day
|Type||10 rpm||20 rpm||40 rpm||60 rpm||80 rpm||100 rpm||120 rpm||140 rpm|
|PT 05 (3 Lobe)||3.4||6.8||13.6||20.4|
|PT 10 (3 Lobe)||10||20||40||60|
|Type||10 rpm||20 rpm||30 rpm||35 rpm||40 rpm||45 rpm||50 rpm|
Optional Executions & Extras
- Twin headed – 2 pump heads fixed to the same gear box.
- PTS Versions with extended shaft for long coupled executions. Supplied with removable bearing case for easy bearing maintenance. Can be converted back to close coupled design at any time.
- PTX Models feature Rollers for pumps without Lubricant
- PT CIP Models for Clean In Place (CIP) applications
- Tri-Lobe design for precise dosing
- Special coatings & casing materials for extreme applications
- Heating Coils to maintain fluid temperature
- Various connection options such as SMS, Clamp, DIN, ANSI, coupling and cover.
- Hose rupture detector and revolution counter with digital display or pulsed output
- ATEX II & I certification
- Variable Speed with mechanical or electronic speed variator or variable speed drive with forced ventilation (1 – 100 Hz) or without (15 – 100 Hz)
- Vacuum Assist System for aiding with suction lift for fluids over 12’000 cPs
- Trolley mounted
- Various Drive Options: Diesel Driven, Hydraulically Driven.
|PT100 Twin Headed Unit||PT25, Diesel Driven on carry frame||PT20 Multi-headed, for precise & equal dosing|
PT Peristaltic Pumps vs Air Operated Diaphragm Pumps
- Air-operated diaphragm pumps require a compressed air supply to drive them. If this does not already exist it can be very expensive to install. Even the best-maintained air supply systems are inefficient with at least 30% air leakage. The energy costs of supplying air for an AODD are much higher than for a peristaltic pump.
- Air pressure limits the discharge pressure – it just stops pumping beyond its limits.
- Changing pumped fluid is complex as cleaning an air-operated diaphragm pump is difficult, often requiring a complete strip-down. Tapflo PT Series pumps offer a quick maintenance schedule on their pumping elements. Change the tube, create a new pump.
- The difficulty in accurately controlling air supply makes the AODD a poor choice for metering duties.
- Even double diaphragm pumps have a high level of pulsation.
- As with all diaphragm pumps, AODDs generally rely on ball valves. These do not work well unless there is positive back pressure to close them between cycles. They are prone to abrasive wear and can clog with crystals, fibres or solidifying fluids such as inks and powders.
- Whilst the initial purchase cost is lower, cost of ownership can much higher due to energy and maintenance costs.
PT Peristaltic Pumps vs Piston Pumps
- Piston pumps rely on ball valves, which must be protected with strainers and yet more valves: back-pressure valves, for example. Foot valves are needed to maintain prime. Valves are prone to clogging and breakdown.
- Piston pumps are expensive to maintain, requiring disassembly for cleaning, which can still be difficult to achieve properly; with the result that contamination is a common problem.
Tapflo PT Series Peristaltic Pumps score on all counts.
- No valves
- No ancillary equipment
- Low maintenance
- Low cleaning
PT Peristaltic Pumps vs Progressing Cavity Pumps
- Progressing cavity pumps cannot run dry, for more than a few seconds. They can self-prime but if the fluid takes time to get to the pump then the rotor/stator must either be manually lubricated or the pump needs initially priming.
- Progressing cavity pumps suffer from wear if particles drop out of the solution or if an abrasive suspended solid lodges within the cavity. Wear increases by the square of the speed.
- Progressing cavity pumps have a large stator in alternating in with the rotor and the duty fluid. Stator particles easily become detached and entrained within the fluid flow.
- Progressing cavity pump rotor replacement is a skilled task requiring a long downtime. Pump selection is also a skilled task and many pumps are badly specified which can lead to premature failures in rotors, stators and mechanical seals.
- Once installed a Progressing cavity pump requires a lot of floor space.
Tapflo PT Series Peristaltic Pump score on all counts:
- Unlimited dry running and fully self-priming
- Excellent abrasive fluid handling
- Low spares costs and simple maintenance
- No Mechanical seals
PT Peristaltic Pumps vs Lobe Pumps
- Lobe pumps are not good for metering duties because fluid slips between the lobes and the casing. Peristaltic Pumps have a true positive displacement action – fluid is pushed in front of a tube pinched closed & precise volumetric efficiency.
- Lobe pumps are known for low shear pumping, but Peristaltic Pumps produce an even lower shearing effect.
- Lobe pumps are generally not good with abrasive fluids or with hard solids. These wear the lobes and can get trapped in the space between the lobes and casing, causing scoring. Worn or damaged lobes reduce capacity through increased slip.
- Lobe pumps have two shafts and so two sets of mechanical seals. These are expensive to maintain and the timing gears need careful resetting after maintenance to ensure lobes do not clash. The fluid does not contact a Peristaltic Pump and vice versa, so abrasives are handled with ease.
- For CIP applications, lobe pumps require by-pass pipework to divert some of the flow. Peristaltic Pumps have a full flow path through the tube for CIP duties. Installation costs are also lower.
- Industrial Lobe pumps are difficult to clean because of dead spots in the casing. Mechanical seals need swabbing to verify cleaning procedures have been effective.
- Lobe pumps are not flexible and must be specifically designed for the application. Changing parameters can cause pumping problems. Temperature changes, for example, can result in “galling”, where flakes of metal from the lobes are released into the fluid, causing contamination.
Tapflo PT Series Peristaltic Pump score on all counts:
- Accurate metering
- Low-shear pumping
- Good abrasive and hard solids handling
- No mechanical seals
- Low cost and simple maintenance
- Simple installation
- Flexible operation
PT Series Hosing
Tapflo only utilise the highest quality compound rubbers which are reinforced with 2 – 6 layers of braided polyamide and an outer layer conforming to the strictest tolerances to ensure perfect and repeatable compression every time.
For the Hose Liner, 7 Materials are available:
- NR: Natural Rubber (White marking): High abrasion resistance, the most flexible.
- NR Food: Natural Rubber certificate CE 1935-2004 and FDA approved, black or white inside: appropriate for the food industry.
- NBR: Nitrile Buna (yellow marking): Appropriate for oils, greases & polymers.
- NBR Food: Nitrile Buna certificate CE 1935-2004 and FDA approved, black or white inside: appropriate for the food industry.
- EPDM: Ethylene Propylene Diene Monomer(red marking) : High chemical resistance
- HYPALON / SYNTHETIC RUBBER: Chlorosulfonated Polyethylene (blue marking): High chemical resistance to fluids like sodium hypochlorite, chromic, nitric, sulfuric acids.
- VITON / FKM: (purple marking): High chemical resistance, especially to solvents, lubricants, petrol’s & fuels. Good temperature resistance.