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Products  |  Fluid Mechanics  |  Hydraulic Fluid Energy Machines  |  HM 285
HM 285 Experiments with a Piston Pump Show data sheet (pdf file) Print page
Technical Description

  Piston pumps belong to the group of positive displacement pumps. They transport the medium by a reciprocating motion of a piston in the pump working space, called stroke. The stroke creates a suction respectively vacuum effect used to deliver the water. Piston pumps are used when high pressures are to be generated. The flow rate of piston pumps is independent of the head and is determined only by speed. Its good suction performance is outstanding.

  The experimental unit provides the basic experiments to get to know the operating behaviour and the important characteristic variables of piston pumps.

  HM 285 features a closed water circuit with water tank, a piston pump with variable speed via frequency converter and an air vessel. The piston of the pump is mounted in a transparent housing and can be observed during operation. The cycle that takes place (intake and discharge of water) can be shown clearly in the p-V diagram. The pulsating pressure curve of the pump can be damped with the aid of the air vessel. Flow rate and head are adjusted via needle valve and overflow valve.

  The experimental unit is fitted with sensors for pressure and flow rate. One pressure sensor measures the pressure at the outlet of the pump, another one measures the pressure in the inside of the cylinder. The position of the piston rod is measured by an angle sensor. This allows the determination of the cylinder volume.

  The microprocessor-based measuring technique is well protected in the housing. All the advantages of software-supported experiments and evaluation are offered by the GUNT software and the microprocessor. The connection to a PC is made by USB.

  The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.


Learning Objectives / Experiments

- principle of operation of a piston pump
- recording of pump characteristics
- pressure curves of delivery pressure and

  cylinder pressure
- influence of pulsation damping

- p-V diagram
- determination of efficiencies



* Illustrative model of a typical positive displacement

* Closed water circuit1
* GUNT software for data acquisition, visualisation

  and operation1

* Part of the GUNT Labline fluid energy machines

Alternative products
HM 365.17 -- Piston Pump Module

[1] functioning and operating behaviour of a piston pump

[2] closed water circuit contains piston pump with variable speed via frequency converter, transparent water tank and air vessel

[3] transparent housing for observing the pump piston

[4] needle valve for adjusting the flow rate

[5] overflow valve for adjusting the head

[6] pulsation damping of the delivery pressure using air vessel with bleed valve

[7] sensors for pressure on delivery side and in the cylinder of the pump, flow rate and crank angle

[8] microprocessor-based measuring technique

[9] unit-specific GUNT software for data acquisition and operation via USB under Windows XP,  Windows Vista or Windows 7 


Technical Data

Piston pump
- speed: 30...180min-1 

- max. flow rate: 135L/h
- max. head: 40m
Drive motor

- power: 180W
- speed: 1.360min-1

Gear transmission ratio: i=7,5

Overflow valve: 1...4bar


Measuring ranges

- pressure (cylinder): 0...5bar

- pressure (delivery side): 0...5bar

- crank angle: 0...360

- flow rate: 0,2...6L/min


Dimensions and Weight

LxWxH: 670x590x740mm

Weight: approx. 49kg

Required for Operation
230V, 50/60Hz, 1 phase or 120V, 60Hz/CSA, 1 phase
Scope of Delivery
1 experimental unit

1 GUNT software CD + USB cable
1 set of instructional material

Order Details

070.28500  HM 285  Experiments with a Piston


© 2005 G.U.N.T. Gerätebau GmbH