Pump testing - An application report -

Vogelsang & Benning GmbH Hansastr. 92 Tel. +49 (0) 2327 – 547-0 D-44866 Bochum Fax +49 (0) 2327 – 547-100 P.O Box 60 02 62 info@vogelsangbenning.de D-44842 Bochum www.vogelsangbenning.de

State of the art pump testing

The quality assurance of pumps is essential and the requirements on manufacturers are highly demand-ing. Analysis of efficiency factors and energy effi-ciency classes take place in accordance with ISO 9906 and EN 60030-2. This is no simple task, even for a renowned traditional company such as “Speck Pumpen” from Roth (GER). The manufacturer pro-duces approx. 250,000 liquid and vacuum pumps every year. In order to continue satisfying the in-creasing quality demands of the market, the compa-ny is now investing in a new test field for centrifugal and side channel pumps. In doing so, “Speck Pumpen” is once again calling upon the ex-pertise of “Vogelsang & Benning”.

Test stand for the acquisition of QH characteristic curves "Due to positive past experiences, we opted for Vogelsang & Benning. They possess extraordinary know-how in design and construction of testing facilities and test systems for drive and pump tech-nology" says Dr.-Ing. Marc Stricker - managing direc-tor of “Speck Pumpen” - in explaining the company's decision, before adding that not only the technology

but also the automation used constituted a decisive advantage here The constructive cooperation between “Vogelsang & Benning” and “Speck Pumpen”, with mutual plan-ning, design and execution, therefore led to opti-mum results. The test field enables testing on dry-installation centrifugal pumps. The specimens arrive at the test stand as separate pumps or as a complete unit with their own customer motor.

The supply of the complete unit is assured by a vari-able AC supply with the following performance data: 110 kVA / 0…720 V / 30…90 Hz / max. 250 A. In this way it is possible to reproduce all voltage variants that apply worldwide. The complete system consists of a plant part with open tank system and a plant part with a vacuum-

proof container. The open part facilitates the record-ing of QH characteristic curves on three test stands. The closed part also enables the execution of NPSH tests on a test stand alongside QH measurements. This is a closed, vacuum-proof tank system produced from stainless steel with pressure-side pipe swivel joints. The suction-side pressure is lowered by a vac-uum pump produced in-house. In all, it is possible to realise measurements with the new test field at flow volumes of up to 700 m³/h, as well as maximum pressures of 40 bar.

The installation includes three test trolleys, which are highly flexible in use and can be used to fix and drive the pumps. Each is equipped with a height-adjustable test motor, as well as a height-adjustable adapter plate for the pumps. The 5.5 kW, 30 kW and 90 kW test motors are equipped with graded torque measurement shafts according to their output, for the acquisition of the pump input power. Each drive has its own frequency converter for stepless speed adjustment between 0 and 3.000 rpm.

The test field enables the following measurements: Acquisition of the QH characteristic curve, NPSH and endurance testing. All of the requisite parameters are determined here, such as suction and delivery pressure, volumetric flow, speed, torque, shaft pow-er, temperatures, current, voltage, electrical power and power factor. Calculations include the overall and individual efficiency factors for the motor and pump, and comprehensive test logs are generated.

Configuration and functionality of the plant Control is implemented via a central operating com-puter. This is subordinate to a PLC, which is respon-sible for the activation of the actuation and control elements, the drive supply and all further digital control commands. The electrical supply is guaran-teed by a frequency converter with downstream transformer. The sensor system is largely equipped with ProfiBus interfaces. The further scope of supply includes measured value acquisition, switchgear, control technology, as well as connection and system cabinets.

The test processes can be performed manually or automatically according to preference. The modular

configuration of the test and evaluation software (operating system Windows 7) developed by “Vogel-sang & Benning” enables the free configuration of a test plan. The measured values are stored centrally and are available to the customer across the compa-ny.

Test stand for the acquisition of NPSH and QH characteristic curves

I & C schematic for the NPSH and QH test stand