Measuring services (2)
Measurements on centrifugal pumps
One of the main activities of our measuring service department is the testing of centrifugal pumps. During the design phase extensive measurements are made on (scale) models of the impeller and the pump housing. Existing pumps are tested to ensure their compliance with customer requirements.
The measurements comprise the measurement of vacuum, delivery pressure, flow rate and shaft speed and torque. The Q-H diagram and pump efficiency curve can then be determined from these data. Extension of these measurements affords information concerning the cavitation behaviour of the pumping installation.
Measurements of pipeline losses are used for the validation of models for pipeline slurry flow. This leads to more accurate prediction of actual pipeline losses, which has great influence on the production of a dredge and the amount of power that has to be installed.
The resistance encountered in straight sections, bends, ball joints, swan-neck bends and other components of a pipeline can be measured as a function of the flowrate and density of the mixture and the characteristics (e.g. grain size) of the soil.
Wear measurement
These consist of measuring the wall thickness of pump housings, pipelines, etc. by means of ultrasonic equipment. Faults in cast components can also be traced with this equipment.
Noise measurements
Using high-precision equipment, the noise level produced by machinery is measured according to various national standards. The level can be determined in dB A or for a wide-frequency spectrum.
Vibration measurements
The source of the vibration is localised with the aid of electronic equipment the direction and level of the vibration being determined as well. Radial vibration from revolving shafts is measured by means of two inductive sensors.
Measurement of forces, stresses and elongation
The Measuring Department is extremely well equipped, both in terms of experience and equipment, to perform stress measurements in all kinds of structures, such as the legs of a self-elevating platform, cranes, diesel engine beds, dredgepump covers and winch foundations.
Bollard pull test:
Towing forces are measured by means of specially calibrated tensile force gauges. The power delivered to the propeller shafts can be simultaneously measured. The measurement signals are dynamically registered.
Data acquisition:
Data loggers and recorders are available for the acquisition of data covering complete processes. The data obtained are elaborated with the aid of computer programmes specially developed for this purpose.
Calibration of measuring equipment:
The MTI laboratory has a wide range of calibration equipment at its disposal. Some of the basic measuring equipment is regularly checked according to international standards.
Troubleshooting:
Years of experience in the field of measurement and the availability of a wide range of measuring and recording devices provide a unique service for identifying and analysing the cause of malfunctions or breakdowns.
Some of the measuring equipment was specially developed for the use in exceptional circumstances, which are common in a dredging environment. Typical examples are the measurements on submerged equipment and the measurements in pipeline systems carrying sand/water mixtures.