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Piston Dosing Pump 180 L / Hour at 20.0 Bar

Piston Dosing Pump TAP25-38 with PVC head

TAP25-38 Piston Dosing Pump available with a choice of 3 gearbox sizes and either Stainless Steel or PVC head materials.

TAP25-38 Piston Dosing Pump Introduction

The TAP25-38 Piston Dosing Pump works on a cavity displacement principle with a reciprocating piston, causing a linear volumetric displacement enabling steady, even and continuous chemical metering.

As a process device, the TAP25-38 is designed to deliver a defined amount of chemical reagent with high precision. Manufactured with an aluminium body and foot mounting stand, the TAP25-38 is designed to be horizontally mounted and connected to a process using the 1/2" BSP connections.

The TAP25-38 is driven from a 3 phase 0.37kW 400VAC motor and is also available with a single phase 0.55kW 230VAC motor.

TAP25-38 Piston Dosing Pump Head Options

The TAP25-38 Dosing Pump is available with a choice of two head material types, either all manufactured in 316 Stainless Steel or manufactured in PVC with a ceramic piston.  The piston has a 25mm stroke length and a diameter of 38mm.

As well as the head material, the other liquid end components, otherwise known as wetted parts, which constitute the materials in contact with the solution to be dosed, are available in a choice of materials, to provide greater compatibility with a range of chemicals.

Head MaterialPiston MaterialSeal MaterialBall Valve MaterialValve Seat MaterialConnections
PVC Ceramic Viton / EPDM Ceramic PTFE 1/2" BSP
Stainless Steel 316 Stainless Steel Viton / EPDM 316 Stainless Steel 316 Stainless Steel 1/2" BSP

The TAP25-38 makes use of a double ball valve for both the suction side and discharge side of the pump, to aid both priming of the pump and to ensure precision chemical delivery during operation.

The valve seats are available in either EPDM or Viton (© DuPont / Chemours) and we recommend checking our chemical compatibility database and your chemical supplier to ensure that all the parts of the liquid end are compatible with the chemical to be dosed.

TAP25-38 Gear Box Options

As with all the pumps in our TAP range, the TAP25-38 is available with a fixed speed gear box to give either 58 strokes per minute, 78 strokes per minute or 116 strokes per minute.

By increasing the number of strokes per minute, the output flow rate of the pump changes as per the following table:-

Model NumberStrokes / MinuteLitres / HourMax Pressure (316 SS)Max Pressure (PVC)Connections
TAP25-38-58 58 0 - 90.0 20.0 Bar 10.0 Bar 1/2" BSP
TAP25-38-78 78 0 - 120.0 20.0 Bar 10.0 Bar 1/2" BSP
TAP25-38-116 116 0 - 180.0 20.0 Bar 10.0 Bar 1/2" BSP

Piston Dosing Pump Adjustable Flow Rate

The TAP25-38 has a micrometer stroke length adjustment dial, mounted at the side of the pump.  This allows the stroke length to be reduced from the maximum length of 25mm so that the flow rate can be set to anywhere between 0 - 100% of the strokes full output.  To maintain accuracy we don't advocate running the pump below 20% of the rated output.

TAP25-38 Features & Benefits

The TAP25-38 piston dosing pump is a foot mounting piston dosing pump, designed to be secured onto a horizontal surface to deliver a chemical reagent to a process.  With accurately machined and assembled components, the TAP25-38 is designed to meter a defined volume of chemical steadily and evenly into a process, with high precision.

The TAP25-38 can be fitted with either a 0.37kW 3 phase 415 VAC motor or a 0.55kW 3 phase 230 VAC motor.

Each motor drives a gearbox which either outputs 58, 78, or 116 strokes per minute, with an output of 90.0 Litres / Hour, 120.0 Litres / Hour, or 180.0 Litres / Hour respectively. Each option has a maximum pressure output of 20.0 Bar when using a 316 Stainless Steel Head or 10.0 Bar with the head material in PVC.  Both options have 1/2" BSP connections for easy connecting directly into a process.

The TAP25-38 includes a range of options for the liquid end or wetted parts, including options for 316 Stainless Steel, or PVC with a ceramic piston and either Viton or EPDM seals / O-rings.

With a micrometer adjustment, the output rate of the pump can be user adjusted between 0 - 100% of the flow rate, to give greater control over your chemical dosing.

The TAP25-38 is fully compatible with a range of dosing accessories including: pulsation dampeners, anti-syphon, back pressure and safety valves.

TAP25-38 Specifications

  • Specifications


    Piston Dosing Pump

    Model Number:- TAP25-38

    Pressure (PVC):- 10.0 Bar (20.0 Bar PVC version available)

    Pressure (Stainless Steel):- 20.0 Bar

    Max Flow Rate 58 Strokes / Min:- 90.0 Litres / Hour

    Max Flow Rate 78 Strokes / Min:- 120.0 Litres / Hour

    Max Flow Rate 116 Strokes / Min:- 180.0 Litres / Hour

    3 Phase Motor:- 0.37kW 400VAC

    Single Phase Motor Option:- 0.55kW 230VAC

    Piston Diameter:- 38mm

    Stroke Length:- 25mm

    Connections:- 1/2" BSP 

    Head Material Options:- 316 Stainless Steel or PVC with ceramic piston

    Dimensions PVC:- 

    • X:- 147 mm
    • Y:- 258 mm
    • W:- 80 mm
    • Weight:- 15.6 Kg

    Dimensions Stainless Steel:- 

    • X:- 160 mm
    • Y:- 268 mm
    • W:- 88 mm
    • Weight:- 18.4 Kg
  • Ordering Information

    Model NumberStrokes / MinHead MaterialBalls & PistonSealsFlow (L/Hr)Pressure (Bar)Connections
    TAP25-38-58-PVC-D 58 PVC Ceramic EPDM 0 - 90.0 10.0 1/2" BSP Male
    TAP25-38-58-PVC-V 58 PVC Ceramic Viton 0 - 90.0 10.0 1/2" BSP Male
    TAP25-38-58-SS-D 58 316 SS 316 SS EPDM 0 - 90.0 20.0 1/2" BSP Male
    TAP25-38-58-SS-V 58 316 SS 316 SS Viton 0 - 90.0 20.0 1/2" BSP Male
    TAP25-38-78-PVC-D 78 PVC Ceramic EPDM 0 - 120 10.0 1/2" BSP Male
    TAP25-38-78-PVC-V 78 PVC Ceramic Viton 0 - 120 10.0 1/2" BSP Male
    TAP25-38-78-SS-D 78 316 SS 316 SS EPDM 0 - 120 20.0 1/2" BSP Male
    TAP25-38-78-SS-V 78 316 SS 316 SS Viton 0 - 120 20.0 1/2" BSP Male
    TAP25-38-116-PVC-D 116 PVC Ceramic EPDM 0 - 180 10.0 1/2" BSP Male
    TAP25-38-116-PVC-V 116 PVC Ceramic Viton 0 - 180 10.0 1/2" BSP Male
    TAP25-38-116-SS-D 116 316 SS 316 SS EPDM 0 - 180 20.0 1/2" BSP Male
    TAP25-38-116-SS-V 116 316 SS 316 SS Viton 0 - 180 20.0 1/2" BSP Male

    Please use our chemical compatibility checker to ensure that the wetted parts are compatible with your process. If you're unsure please don't hesitate to contact our friendly sales team.

    Single phase and 3 phase motors are available - for corresponding part numbers please speak with our friendly sales team.


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