Positive Displacement Pumps

Positive displacement pumps are speciality pumps that provide an approximate constant flow of fluid at the fixed speed. Pump trap a fixed amount of the fluid and then force it into a discharge pipe. Positive displacement pumps can produce the same flow at a given speed (RPM) no matter what the discharge pressure is. These type of pumps cannot operate against the closed valve because they have no shutoff head like centrifugal pumps. Positive displacement pumps constantly produce flow and the pressure built within the blocked line will damage the line, pump or both.
The positive displacement pumps can be divided into two main categories:
A. Rotary pumps are very efficient because they can operate even with highly viscous fluids but require a slow steady speed rotation. If the mechanism rotation is too fast, the fluid can cause erosion, which eventually causes enlarged clearances that liquid can pass through and reduce pressure.
Rotary pumps can be divided into three main types:
• Gear pumps: the simplest pump type that pumps liquid using 2 gears.
• Screw pumps: more complicated pump type where the two screws are positioned against each other to pump the liquid.
• Rotary vane pumps: these pumps have a cylindrical rotary engine. As the rotor circulates, vans trap fluid between the rotor and the engine housing, pushing the liquid through the pump.

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Description Price Pump Type Drive Type Maximum Flow Rate Maximum Head Maximum Working Pressure Input Connection Output Connection IP Rating Series Maximum Fluid Temperature Body Material Supply Voltage Input Power Wetted Materials
RS Stock No. 667-9113
Mfr. Part No.G573215A
MYR1,360.42
Each
units
Diaphragm Air 19L/min - 6.9 bar 1/2 in Hose Barb, 1/4 in Hose Barb 1/2 in Hose Barb, 1/4 in Hose Barb - G5732 +48.9°C PP - - Hastelloy C, Kalrez, PP, Santoprene, Viton
RS Stock No. 705-9333
Mfr. Part No.R3711132A
MYR780.53
Each
units
Diaphragm Electric 5.5L/min 69m 6.9 bar 3/8 in BSP 3/8 in BSP - R371 +60°C Glass Fibre Reinforced Nylon 12 V dc 108W -
RS Stock No. 667-9116
Mfr. Part No.G575215A
MYR1,051.92
Each
units
Diaphragm Air 19L/min - 8.27 bar 1/2 in Hose Barb, 1/4 in Hose Barb 1/2 in Hose Barb, 1/4 in Hose Barb - G5752 - PP - - Hastelloy C, Kalrez, PP, Santoprene, Viton
RS Stock No. 705-9349
Mfr. Part No.R3811142A
MYR804.20
Each
units
Diaphragm Electric 5.5L/min 105m 10.5 bar 3/8 in NPT 3/8 in NPT - R381 +60°C Glass Fibre Reinforced Nylon 12 V 108W -
RS Stock No. 667-9100
Mfr. Part No.D3131H5011AR
MYR902.99
Each
units
Diaphragm Electric 5.3L/min 30m 4.2 bar 3/8 in NPT 3/8 in NPT IP44 D3131 +54°C Glass Filled PP 12 V dc - -
RS Stock No. 667-9104
Mfr. Part No.D3135H7011AR
MYR948.66
Each
units
Diaphragm Electric 8.1L/min 30m 7.1 bar 3/8 in NPT 3/8 in NPT IP44 D3135 - Glass Fibre Reinforced PP 12 V - -
RS Stock No. 705-9343
Mfr. Part No.R3811342A
MYR1,086.50
Each
units
Diaphragm Electric 5.3L/min 105m 10.5 bar 3/8 in NPT 3/8 in NPT - R381 +60°C Glass Fibre Reinforced Nylon 24 V 108W -
RS Stock No. 446-3506
Mfr. Part No.416990
MYR1,705.97
Each
units
Diaphragm Electric 10.8L/min 28m 15 bar 1/2 in NPT 1/2 in NPT IP44 AD +60°C - 230 V 33W -
RS Stock No. 705-9321
Mfr. Part No.RLFP122202D
MYR470.00
Each
units
Diaphragm Electric 3.8L/min 21m 2.5 bar 3/8 in Hose Barb 3/8 in Hose Barb - RLF122 +43°C PP 12 V dc 30W EPDM, PP, Santoprene, Stainless Steel, Viton
RS Stock No. 705-9352
Mfr. Part No.R3811242A
MYR1,313.93
Each
units
Diaphragm Electric 5.5L/min 105m 10.5 bar 3/8 in NPT 3/8 in NPT - R381 +60°C Glass Fibre Reinforced Nylon 230 V - -
RS Stock No. 705-9355
Mfr. Part No.R3521139A
MYR926.58
Each
units
Diaphragm Electric 15.1L/min 41m 4.1 bar 1/2 in Hose Barb 1/2 in Hose Barb IP54 R352 +60°C PP 12 V 108W -
RS Stock No. 705-9327
Mfr. Part No.RLF222201D
MYR499.76
Each
units
Diaphragm Electric 3.8L/min 21m 2.5 bar 3/8 in Hose Barb 3/8 in Hose Barb - RLF222 +43°C PP 24 V dc 30W -
RS Stock No. 705-9359
Mfr. Part No.R3521339A
MYR936.53
Each
units
Diaphragm Electric 7.6L/min 41m 4.1 bar 3/4 in NPT 3/8 in NPT - R352 +60°C PP 24 V 144W -
RS Stock No. 667-9093
Mfr. Part No.R4300143A
MYR1,062.94
Each
units
Diaphragm Electric 19L/min - 3.1 bar 3/4 in Hose Barb 3/4 in Hose Barb IP44 R4300 - PP 12 V dc - Buna, Elastomer, PP
RS Stock No. 763-2480
Mfr. Part No.G70K202A
MYR1,638.33
Each
units
Diaphragm Air 18.9L/min - 100 psi 6 mm Hose 9.5 mm to 15 mm Hose - G70K +49°C PP - - -
RS Stock No. 667-9097
Mfr. Part No.R4300242A
MYR1,378.84
Each
units
Diaphragm Electric 12L/min 40m 2.1 bar 1/2 in Hose Barb 1/2 in Hose Barb IP44 R4300 +54°C Glass Fibre Reinforced PP 230 V ac - -
RS Stock No. 705-9330
Mfr. Part No.RLFP222202D
MYR502.36
Each
units
Diaphragm Electric 3.8L/min 25m 2.4 bar 3/8 in Hose Barb 3/8 in Hose Barb - RLF222 +43°C PP 24 V dc 30W -
RS Stock No. 763-2471
Mfr. Part No.G57C202A
MYR1,463.01
Each
units
Diaphragm Air 19L/min - 100 psi 1/4 in Hose Barb 3/8 in Hose Barb - G57C +49°C PP - - Hasteloy C, PP, Santoprene, Viton
RS Stock No. 705-9324
Mfr. Part No.RLFP122201D
MYR534.78
Each
units
Diaphragm Electric 3.8L/min 21m 2.5 bar 3/8 in Hose Barb 3/8 in Hose Barb - RLF122 +43°C PP 12 V dc 30W EPDM, PP, Santoprene, Stainless Steel, Viton
RS Stock No. 146-6434
Mfr. Part No.R4300342A
MYR1,121.34
Each
units
Diaphragm Automatically Operated 3.7 g/min, 14 L/min - 3.1 bar 1/2 in Hose Barb 1/2 in Hose Barb - QUAD 4000 +54°C PP 24 V dc - Elastomer, Polypropylene (Housing)