Pumping Mechanism - Gear Pump vs Centrifugal Pump
A Gear Pump is a "positive displacement" pump, unlike a centrifugal pump which is a "velocity" type pump. As the term suggests, a "velocity" type pump generates pressure and flow from the tangential and angular velocities(kinetic energy) imparted to the liquid by the speed and shape of the impeller. In a "velocity" type pump, pressure and flow can be modulated by throttling a discharge valve.
In a gear pump, a volume of liquid is isolated in each tooth cavity. As the gears mesh, that cavity is reduced in volume. Since liquid is virtually incompressible, the reduced cavity generates pressure nearly independently of the gear speed and forces the liquid out the discharge port. Therefore, with a gear pump flow is relatively constant over varying pressures and throttling a discharge valve will not appreciably affect flow rate. To alter the flowrate with a gear pump, the RPM of the pump must change.
Since the means of generating pressure and flow in "positive displacement" pumps is by compressing a nearly incompressible liquid, extremely high pressures can be generated very rapidly in closed discharge piping. Therefore, it is highly recommended that a pressure relief valve be inserted in the discharge piping, upstream of the first potential blockage (closed valve, pipe obstruction).
Design Advantages of Dynaflow Engineering Alloy GearPumps
Our gear pumps incorporate design features that will extend their accuracy, reliability, and maintainability over many years of service.
Our gear pumps incorporate design features that will extend their accuracy, reliability, and maintainability over many years of service.
FACT: Our pump housings are machined from bar stock and are thick walled. Many competiitors use cast housings, which require thinner wall designs to minimize shrinkage and cracking upon cooling.
RESULT: Our pumps can handle higher system pressures. Additionally, they provide a greater safeguard against unforeseen pitting and general corrosive attack.
FACT: Our G3000 and higher series of gear pumps utilize two housings to retain the bearings, shafts, gears, and wearplates. Competitive pumps utilize three or more housings.
RESULT: With two precisely machined housings, the probability of bearing misalignment and accelerated wear is greatly reduced.
G3000 & G6000 Series Housings
FACT: Our pumps utilize an integral, one piece drive shaft and drive gear machined from bar stock. Competitive pumps, employing an alloy drive gear, typically slide the gear onto the drive shaft.
RESULT:The one piece drive shaft and drive gear provide improved concentricity over the two piece assembly. This provides quieter running and extended gear life.
Integral Drive Shaft/Gear
FACT: Our plastic idler gear is thermally secured to the idler shaft without keying. It is then machined as an integral unit.
RESULT: This construction provides improved concentricity over keyed gearing. Additionally, stress risers, which are induced in keyed gearing and which may lead to fatigue failure, are substantially reduced in our design.
Integral Idler Shaft/Gear
FACT:Our typical configuration consists of an alloy drive gear mated to an engineered plastic idler gear.
RESULT:With two dissimilar gear materials exhibiting substantially different hardnesses, a non-lubricating liquid can be pumped at high speeds without galling or frictional drag. In utilizing engineered plastics, wear of the idler gear is minimized.
Alloy Gear Mated to Plastic Gear
FACT: Our inner magnet assemblies (foreground) use high strength rare earth magnets, permitting compact designs that generate high torque.
RESULT: Our inner magnet assemblies minimize inertial loading on start up and loading on the bearings.
FACT: Our containment cans, which encompass the inner magnet assemblies, are compact as well. They are also relatively thick walled.
RESULT: As pressure vessels, our smaller containment cans will withstand higher internal pressures at lower stress levels than larger size cans. Additionally, they provide a greater safeguard against unforeseen pitting and general corrosive attack.
Inner Magnet Assy's & Containment Cans
New 8000 Series Mag-Drive Gear Pump
Our G8000 series Mag-Drive gear pump can generate over 21 GPM. It shares the same design features as our current line of pumps.
G8000 Series Mounted to Motor
Our G8000 series is machined from bar stock, permitting wall thicknesses unattainable from castings. As with our G3000 - G6000 series, two housings instead of three are used to retain the bearings, shafts, gears and wearplates. This reduces the possibility of misalignment and accelerated wear.
G6000 & G8000 Series Housings
Our G8000 series uses an integral one piece drive shaft and drive gear machined from bar stock. As with our G3000 - G6000 series, the one piece construction improves concentricity over a twopiece (shaft and separate gear) assembly.
G6000 & G8000 Integral Drive Shaft/Gear
Our G8000 series plastic idler gear is thermally secured to the idler shaft without keying. It is then machined as an integral unit. As with our G3000 - G6000 series, this construction improves concentricity and reduces fatigue failure over keyed gears.
G6000 & G8000 Idler Shaft/Gear
Our typical configuration of the G8000 series consists of an alloy drive gear mated to an engineered plastic idler gear. As with our G3000 - G6000 series, running an engineering plastic against an alloy metal permits pumping non-lubricating liquids without galling.
G6000 & G8000 Series
Our G8000 series incorporates a larger inner magnet, providing ample torque for the maximum rated flow and pressure. As with our G3000 - G6000 series, our containment cans are machined from bar stock, where we can generate greater wall thicknesses in areas more susceptible to deformation.
G6000 & G8000 Inner Mag & C’ Can
G4000R Mag-Drive Gear Pump
Our G4000R series Mag-Drive gear pump, where conditions permit (pressure and temperature), can be a lower cost substitute for our G4000 series in Alloy C276. Although not as rugged as an alloy pump, construction in 40% glass reinforced PPS (polyphenylene sulfide) provides mechanical strength and chemical resistance not found in other plastics used for pumps. Machining from bar stock permits wall thicknesses of housings and containment cans that are unattainable through molding. With shafting in Alloy C276 or Titanium, the G4000 R series is capable of handling such chemicals as hydrochloric acid, sodium hypochlorite, and ferric chloride.
G4000R Pump Mounted To Motor
Standard Materials of Construction
G3000S, G4000S, G4500S, G5000S, and G6000S
316 SS Series
| Component | Material |
|---|---|
| Housings | 316 Stainless Steel |
| Drive Shaft/Integral Drive Gear | 316 Stainless Steel 17-4 PH |
| Idler Shaft | 316 Stainless Steel |
| Integral Idler Shaft/Gear | 316 Stainless Steel 17-4 PH Nitronics® 60 |
| Idler Gear(Plastic) | PEEK (Polyetheretherketone) Torlon ® (Polyamide-imide) |
| Bearings/Wearplates | Rulon® Carbon PEEK (Bearing grade) PPS (Polyphenylene Sulfide Brg. grade) Polyethylene (U.H.M.W.) Teflon® Composite |
| Inner Magnet Assembly (Mag Drive) | Rare Earth Magnets Enclosed in 316L Stainless Steel |
| Containment Can (Mag Drive) | 316 Stainless Steel |
| Elastomer | Viton® EPDM Buna N Silicone Kalrez® |
G8000S
316 SS Series
| Component | Material |
|---|---|
| Housings | 316 Stainless Steel |
| Drive Shaft/Integral Drive Gear | 316 Stainless Steel |
| Idler Shaft | 316 Stainless Steel |
| Integral Idler Shaft/Gear | Nitronics® 60 |
| Idler Gear (Plastic) | PEEK (Polyetheretherketone) |
| Bearings/Wearplates | Carbon PEEK (Bearing grade) Polyethylene (U.H.M.W.) Teflon® Composite |
| Inner Magnet Assembly (Mag Drive) | Rare Earth Magnets Enclosed in 316 L Stainless Steel |
| Containment Can (Mag Drive) | 316 Stainless Steel |
| Elastomer | Viton® EPDM Buna N Kalrez® |
Specifically for Sulfuric Acid
G3000A, G4000A, G4500A, G5000A, and G6000A
Alloy 20 Series
| Component | Material |
|---|---|
| Housings | Alloy 20 |
| Drive Shaft/Integral Drive Gear | Alloy 20 |
| Idler Shaft | Alloy 20 |
| Integral Idler Shaft/Gear | Alloy 20 |
| Idler Gear (Plastic) | PPS(Polyphenylene Sulfide) |
| Bearings/WearPlates | Carbon PPS (Polyphenylene Sulfide Brg. grade) Polyethylene (U.H.M.W.) Teflon® Composite |
| Inner Magnet Assembly (Mag Drive) | Rare Earth Magnets Enclosed in Alloy 20 |
| Containment Can (Mag Drive) | Alloy 20 |
| Elastomer | Viton® Kalrez® |
G3000H, G4000H, G4500H, G5000H, and G6000H
Alloy C276 Series
| Component | Material |
|---|---|
| Housings | Alloy C276 |
| Drive Shaft/Integral Drive Gear | Alloy C276 |
| Idler Shaft | Alloy C276 |
| Integral Idler Shaft/Gear | Alloy C276 |
| Idler Gear (Plastic) | PEEK (Polyetheretherketone) PPS (Polyphenylene sulfide) |
| Bearings/WearPlates | Rulon® Carbon PEEK (Bearing grade) PPS (Polyphenylene Sulfide Brg. grade) Polyethylene (U.H.M.W.) Teflon® Composite |
| Inner Magnet Assembly (Mag Drive) | Rare Earth Magnets Enclosed in Alloy C276 |
| Containment Can (Mag Drive) | Alloy C276 |
| Elastomer | Viton® EPDM Buna N Kalrez® |
G4000R
PPS Series
| Component | Material |
|---|---|
| Housings | PPS (polyphenylene Sulfide Glass Filled) |
| Drive Shaft/Integral Drive Gear | Alloy C276 Titanium |
| Idler Shaft | Alloy C276 Titanium |
| Idler Gear | PEEK (Polyetheretherketone) PPS (Polyphenylene Sulfide) |
| Bearings/WearPlates | Rulon® Carbon PEEK (Bearing grade) PPS (Polyphenylene Sulfide Brg. grade) Polyethylene (U.H.M.W.) Teflon® Composite |
| Inner Magnet Assembly (Mag Drive) | PPS (Polyphenylene Sulfide Glass Filled) |
| Containment Can (Mag Drive) | PPS (Polyphenylene Sulfide Glass Filled) |
| Elastomer | Viton® EPDM Buna N Kalrez® |
Metering With A Gear Pump
As "Positive Displacement" pumps, gear pumps can provide relatively constant flow over a wide range of pressures.
When mounted to a variable speed motor and controller, a gear pump offers several advantages over "reciprocating type" metering pumps. Unlike the aforementioned pumps, gear pumps offer non-pulsating flow. Piping is simplified, because pulsation dampeners and back pressure valves are not required. Liquids, which have a tendency to "gas off", create priming difficulties with the "reciprocating type" pumps. Since gear pumps are inherently self priming and their non-pulsating flow does not agitate the liquid, they may be better choices for these applications.
Metering System: Ext. Signal Capable
Metering with gear pumps can be adjusted by manual and by external means, such as a 4-20 mAmp signal.
The simple construction of our gear pumps afford long term reliability. Additionally, our gear pumps with variable speed motors and controllers are very cost competitive.
NEMA 4X AC & DC Controllers
Representative Applications
The following is a small sample indicating the capabilities of our Mag-Drive gear pumps.
- G3000 Series transferring 98% Sulfuric Acid from a 55 gallon drum; self priming required.
- G3000 and G4000 Series for metering various solvents, including MEK, Methanol, Diacetone Alcohol, and Butylacetate for an ink manufacturer; manual control; replaced competitor's gear pumps which could not handle the low viscosities.
- G3000 Series for metering herbicides in a pilot plant; pump incorporated flush plugs and a drain plug to clean the pump without disassembly; manual control; pump was mounted to an air motor.
- G3000 Series for metering pigment which included titanium dioxide; differential pressure 15 PSI; .02 GPM; mounted to a 4:1 ratio in-line gear reducer.
- G3000 Series for metering 25% Sodium Hydroxide for a scrubber system; external control via 4-20 mAmp signal; replaced a hose pump due to chronic hose failures.
- G3000 Series for metering surfactants for dust suppression in mining; differential pressure 40 PSI; 3-10 GPH.
- G3000 Series for metering alpha and gluco amylase in an ethanol plant.
- G4000 Series for transferring hot vegetable oil at 275°F; pump was heat traced to prevent solidification of oil when pump was not in use.
- G4000 Series for metering 50% sodium hydroxide for a wastewater neutralization system; system uses on-off control; self-priming up to 10' required.
- G4000 Series for metering 75% Phosphoric Acid at a remediation site; external control via 4-20 mAmp signal.
- G4000 Series for metering 2 Megohm de-ionized water; differential pressure 80-100 PSI; up to 12 GPH; external control via 4-20 mAmp signal; mounted to a 2:1 ratio in-line gear reducer.
- G4000 Series for metering 35% hydrogen peroxide; differential pressure 40-65 PSI; up to 9 GPH.
- G4000 Series for metering 50% citric acid; differential pressure 20 PSI; up to 1 GPM.
- G4000R Series for metering up to 15% Sodium Hypochlorite at various municipal waste water treatment facilities. Flows ranged from 40 to over 1000 gallons per day; manual and external controls; replaced diaphragm metering pumps from several manufacturers.
- G4000R Series for metering 32% hydrochloric acid for a PH control system; differential pressure 10-20 PSI; .5 GPM.
- G3000 and G4000 Series for metering detergent from drums into a water stream for commercial truck wash systems.
- G3000 and G4000 Series for metering toluenesulfonic acid in binding core sand for foundries.
- G3000 and G4000 Series for recirculating various "used" refrigerants through a distillation column for purification and reuse.
- G5000 Series for metering polymer for a water treatment plant in a steel mill.
- G5000 Series for recirculating glycol solution as a barrier fluid for a double mechanical seal; suction pressure 700 PSIG; differential pressure 40 PSI; 5 GPM.
- G5000 Series for recirculating barrier fluid for a test rig for a double mechanical seal; suction pressure 1500 PSIG; differential pressure up to 50 PSI; up to 5 GPM.
- G5000 Series for transferring hot vegetable oil at 240°F; pump was heat traced to prevent solidification of oil when pump was not in use.
- G5000 Series for metering 1-1.5 GPM dielectric oil under 29" Hg vacuum.
- G5000 Series for metering 1-1.5 GPM silver nitrate for silver recovery.
- G5000 Series for metering polymer in a chemical plant.
- G6000 Series for metering sodium bisulfite in a wastewater treatment plant.
- G6000 Series for recirculating liquified CO2 at ambient temperature; 900 PSIG suction pressure; 1-1.5 GPM.
- G6000 Series for metering 98% sulfuric acid for a consumer products facility; differential pressure 45 PSI; 4-7 GPM.
- G6000 Series for metering 50% sodium hydroxide at 230F; differential pressure 22 PSI; up to 4 GPM.
- G6000 series for density sampling of various hydrocarbons for custody transfer; suction pressure up to 1350 PSIG; up to 2 GPM.
G4500/G5000 Performance Curves
G6000/G8000 Performance Curves
G4000R Performance Curves
