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: reciprocating positive displacement pumps and rotary pumps.

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. 705-6662
Mfr. Part No.AU EZ3R16 100 02
BrandVerderflex
HK$3,265.29
Each
units
Peristaltic Electric 0.375L/min 20m 1 bar - - - EZ3R1 +40°C Polyamide 12 V dc 17W -
RS Stock No. 705-6653
Mfr. Part No.AU EZ3R16 150 02
BrandVerderflex
HK$3,265.29
Each
units
Peristaltic Electric 0.562L/min 20m 1 bar - - - EZ3R1 +40°C Polyamide 12 V dc 20W -
RS Stock No. 121-8586
Mfr. Part No.BT4B1601PVT2000U1110000
BrandProMinent
HK$9,879.13
Each
units
- Electric 1.1L/h - 16 bar 3/4 in G 3/4 in G IP65 BT4B +20°C PVDF 100 to 230 V 9.6 (Consumption)W PVDF
RS Stock No. 144-850
Mfr. Part No.BL 10/D
HK$2,061.90
Each
units
Diaphragm Electric 10.8L/h - 43.5 psi - - IP65 BL10/D - Glass Fibre Reinforced PP 220 V, 240 V 200W -
RS Stock No. 705-9324
Mfr. Part No.RLFP122201D
HK$1,027.47
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. 705-6684
Mfr. Part No.AU R2550030 RS1
BrandVerderflex
HK$1,996.19
Each
units
Peristaltic Electric 0.06L/min 10m 1 bar - - - R2550 +40°C ABS, PC 12 V dc 6W -
RS Stock No. 122-6642
Mfr. Part No.TEP130-ANB-D
BrandTecnomatic
HK$10,667.88
Each
units
Diaphragm Air 130L/min 8.5m - 1 in Plain 1 in Plain - TEP130 - Aluminium - - Aluminium Body, NBR Diaphragms, NBR Valve Balls
RS Stock No. 121-8602
Mfr. Part No.DF4A0W004015P0U120001210
BrandProMinent
HK$11,904.33
Each
units
Peristaltic Electric 1.5L/h - 4 bar - - IP65 DF4a +20°C - 100 to 240 V 24 (Consumption)W -
RS Stock No. 122-6644
Mfr. Part No.T240-ANB-D
BrandTecnomatic
HK$19,168.94
Each
units
Diaphragm Air 240L/min 8.5m - - - - T240 - Aluminium - - Aluminium Body, NBR Diaphragms, NBR Valve Balls
RS Stock No. 144-866
Mfr. Part No.BL 15/D
HK$2,061.90
Each
units
Diaphragm Electric 15.2L/h - 14.5 psi - - IP65 BL15/D - Glass Fibre Reinforced PP 220 V, 240 V 200W -
RS Stock No. 121-8600
Mfr. Part No.DF2A0224P00A10W1
BrandProMinent
HK$3,971.52
Each
units
Peristaltic Electric 2.4L/h - 1.5 bar - - IP65 DF2a +20°C - 230 V 5 (Consumption)W -
RS Stock No. 705-9330
Mfr. Part No.RLFP222202D
HK$1,007.63
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. 667-9116
Mfr. Part No.G575215A
HK$1,991.03
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. 705-9343
Mfr. Part No.R3811342A
HK$1,849.46
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. 121-8599
Mfr. Part No.DF2A0216P00A10W1
BrandProMinent
HK$3,971.52
Each
units
Peristaltic Electric 1.6L/h - 1.5 bar - - IP65 DF2a +20°C - 230 V 5 (Consumption)W -
RS Stock No. 705-9359
Mfr. Part No.R3521339A
HK$2,101.52
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. 195-3562
Mfr. Part No.DFXAEU0730SPTU0000U11130EN
BrandProMinent
HK$25,354.99
Each
units
Peristaltic - 30L/h 6m 7 bar - - - DFXA - PVDF 100 → 230 V 45W TPV
RS Stock No. 185-6134
Mfr. Part No.164.0165
BrandVerderflex
HK$1,577.30
Each
units
- - 375ml/min 86mm 1 bar - - - - - Nylon, Polycarbonate 24 V dc - -
RS Stock No. 185-6129
Mfr. Part No.164.0146
BrandVerderflex
HK$1,577.30
Each
units
- - 375ml/min 86mm 1 bar - - - - - Nylon, Polycarbonate 24 V dc - -
RS Stock No. 667-9093
Mfr. Part No.R4300143A
HK$2,144.15
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