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. 121-8588
Mfr. Part No.BT4B0708PVT2000U1110000
BrandProMinent
HK$10,302.17
Each
units
- Electric 7.1L/h - 7 bar 3/4 in G 3/4 in G IP65 BT4B +20°C PVDF 100 to 230 V 15.2 (Consumption)W PVDF
RS Stock No. 667-9100
Mfr. Part No.D3131H5011AR
HK$1,731.15
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. 195-3563
Mfr. Part No.DFXAEU0530SPTU0000U11130EN
BrandProMinent
HK$25,354.99
Each
units
Peristaltic - 30L/h 5m 5 bar - - - DFXA - PVDF 100 → 230 V 45W TPV
RS Stock No. 195-3560
Mfr. Part No.GXLAEU1020PVT20000U11130EN
BrandProMinent
HK$25,274.90
Each
units
- - 20L/h 10m 10 bar - - - GXLa - PVDF 230 V 78W PVDF
RS Stock No. 185-6135
Mfr. Part No.164.0126
BrandVerderflex
HK$1,577.30
Each
units
- - 375ml/min 86mm 1 bar - - - - - Nylon, Polycarbonate 24 V dc - -
RS Stock No. 185-6148
Mfr. Part No.164.0001
BrandVerderflex
HK$1,577.30
Each
units
- - 375ml/min 86mm 1 bar - - - - - Nylon, Polycarbonate 24 V dc - -
RS Stock No. 185-6127
Mfr. Part No.164.0130
BrandVerderflex
HK$1,577.30
Each
units
- - - - - - - - - - - - - -
RS Stock No. 126-0254
Mfr. Part No.PA5120-F04
BrandSMC
HK$7,048.64
Each
units
- - - - - - - - - - - - - -
RS Stock No. 185-6137
Mfr. Part No.164.0011
BrandVerderflex
HK$1,577.30
Each
units
- - - - - - - - - - - - - -
RS Stock No. 121-8589
Mfr. Part No.BT4B0413PVT2000U1110000
BrandProMinent
HK$10,302.17
Each
units
- Electric 12.3L/h - 4 bar 3/4 in G 3/4 in G IP65 BT4B +20°C PVDF 100 to 230 V 15.2 (Consumption)W PVDF
RS Stock No. 185-6155
Mfr. Part No.169.6021
BrandVerderflex
HK$820.22
Each
units
- - - - - - - - - - - - - -
RS Stock No. 146-6434
Mfr. Part No.R4300342A
HK$2,185.88
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)
RS Stock No. 121-8603
Mfr. Part No.DF4A0W003060P0U120001210
BrandProMinent
HK$11,452.53
Each
units
Peristaltic Electric 6L/h - 2.5 bar - - IP65 DF4a +20°C - 100 to 240 V 24 (Consumption)W -
RS Stock No. 196-1155
Mfr. Part No.PA3110-F03
BrandSMC
HK$7,378.96
Each
units
- Automatically Operated 200L/min - 0.7 MPa - - - PA3000 +60°C - - - ADC12 (Aluminium)
RS Stock No. 180-9204
Mfr. Part No.S1CBH04120PVTS070UA110S0EN
BrandProMinent
HK$32,032.23
Each
units
Diaphragm Electric 120L/h - 4 bar DN 15 1 in G IP55, IP65 S1Cb +100 °C @ 15 min (2 bar) PVDF 100 → 230 V ac - PVDF
RS Stock No. 185-6130
Mfr. Part No.164.0147
BrandVerderflex
HK$1,577.30
Each
units
- - 375ml/min 86mm 1 bar - - - - - Nylon, Polycarbonate 24 V dc - -
RS Stock No. 185-6110
Mfr. Part No.162.1103
BrandVerderflex
HK$3,217.62
Each
units
- - - - - - - - - - - - - -
RS Stock No. 185-6139
Mfr. Part No.164.0013
BrandVerderflex
HK$1,577.30
Each
units
- - - - - - - - - - - - - -
RS Stock No. 185-6133
Mfr. Part No.164.0164
BrandVerderflex
HK$1,577.30
Each
units
- - 375ml/min 86mm 1 bar - - - - - Nylon, Polycarbonate 24 V dc - -
RS Stock No. 185-6126
Mfr. Part No.164.0129
BrandVerderflex
HK$1,577.30
Each
units
- - - - - - - - - - - - - -