Design:

The hydraulic accumulator sets are systems of several pumps that usually have the same size and which are connected in parallel to the supply and delivery manifolds by non-return and cut-off fittings. The set pumps are installed on a support structure made of steel sections. The support structure features vibration dampers that allow setting the set directly on floors.

The ZHN and ZHM hydraulic accumulator sets are based on parallel connections of NHV and MVA/B single-stage centrifugal pumps.

Pumping units: The NHV pumps are installed on separate base plates and connected via flexible couplings to standardised induction motors of a defined size. The MVA and MVB pumps are monoblock designs with the motor cage and pump impeller installed on the same shaft.

Support structure and manifolds: The support structure of the ZHN and ZHM sets is always specified with the customer. This is required by the large overall dimensions of the compact pumping system. The manifolds and the support structure of pumps and manifolds are made of welded structural carbon steel with dip zinc coating. They are also available made of austenitic steel. The sets feature high quality non-return and cut-off fittings.

It is always possible to customise the solutions to detailed requirements concerning every aspect of the offered set.

Features of the microprocessor controller used in standard ZHM, ZHN set control systems:

• Pump speed control depending on the delivery manifold pressure (in an FC system, h = 1). The control system maintains a constant pressure or its specified values in a defined interval by switching various pumps on and off, and adjusting the RPM of the pump that is currently connected to the frequency converter.
• Switching the pumping unit on and off depending on the delivery manifold pressure (in a cascade system, h = 2). The control system maintains a constant pressure or its specified values in a defined interval by switching various pumps on and off.
• Starting of successive pumping units in the set (by a frequency converter or directly from the mains, or optionally by a thyristor soft starter).
• Pump running time balancing: equalisation of the usage rate and test running of pumps in a set that provides fire water supply (all identical pumps of the set). In this function the first pump to be started is the pump with the shortest running time or with the longest standstill.
• It also prevents starting of more than one pump at the same time. It is possible to set a time delay after which the next pump in the set will start.
• Stopping and switching the set to standby in periods of zero demand.
• Stopping of pumps at programmed permissible pressure setpoints.
• Adjustment of the system's performance of the supplied pipeline characteristics by discrete adjustment of pressure setting values in relation to the number of running pumps or preset measured flow rate (optional connection to a flow meter).
• Readouts of all measured operating parameters.
• Adjustment of parameter settings in relation to time interval settings (option).
• The control system automatically switches to cascade operation when the frequency converter fails.
• The control system enables switching to manual mode when the controller fails.

Features of the controller software:

• Collection of data about the values measured in the last seven days.
• Memory of all operating state changes of the set with precise event times (storage capacity: 1000 events).
• Collection of data about individual pump running times.
• Export/transmission of data packages over a serial link in an agreed format to external devices (radio modems, phone modems, GSM modems, PCs).

Dry run protection

The set pumps are protected as standard from dry running by conductive measurement probes installed in the main bodies of pumps (ZHM, ZHN). In addition, a set that is operated with an open reservoir can feature float switches or a system of conductive measurement probes, or work with a hydrostatic probe that controls the reservoir filling. In this version the set has no pressure transducer on the supply manifold. A set operated on a water supply system has the pump dry run protection with the aforementioned conductive measurement probes and a pressure transducer on the suction/supply manifold. The available optional protection includes an LCA pressure switch installed on the suction/supply manifold of the set.

Installation site considerations:

• The room area should enable installing the hydraulic accumulator set with clearances that enable free access to individual components.
• The ambient temperature at the installation site should be between +5^oC and + 40^oC.
• The room should feature a ventilation system with an air exchange rate of 1/hour or higher.
• Due to the foundation of the set on vibration dampers with levelling, no extra foundation works are necessary for the installation.
• The room floor should have a slope towards floor drains for effective water discharge from the installation site. The running hydraulic accumulator set must be protected from flooding with water.
• If the set is fed by an open storage reservoir, the hydraulic accumulator set should be located to ensure a minimum static flow of 1.0 m at the set connection point. Otherwise contact the manufacturer to select and install a suitable flooding adapter.

Features of sets:

• The design (shape, form and materials) of the set and its control functions is fully adapted to detailed requirements of the customer.
• The applied pumps (up to the capacity Q = 600 m^o/h) comply with PN-EN-733 and assure full interchangeability.
• The traditional single-stage centrifugal horizontal pumps increase durability and operating life of the set with significant simplification of maintenance and servicing.
• The set design enables servicing without stopping the entire pumping unit.

Hydro-Vacuum S.A. Pump Selection Progam.

Quick and simple online tool for pump selection based on set criteria.

Thanks to the PDP, by means of the "Hydraulic Selection" function, specific pumps can be selected by configuring, among other things, the area of application, pump type, pump design, medium to be pumped, operating point, etc. Alternatively, by using the "Product Catalogue", you can conveniently browse through the pump catalogue which is Hydro-Vacuum S.A. 's production offer.

The result of the selection is a data sheet for the pump containing all the necessary hydraulic (characteristics), electrical, material, construction, dimensional, etc. data.

The first thing to do is to register a new account. After entering some necessary data and approving the form, an activation link will be sent to the e-mail address provided. After clicking on the link, you will be able to make full use of the Hydro-Vacuum S.A. Pump Selection Software.

We encourage you to create an account and try our program.
Technical assistance in the operation of the program tel. 56 45 07 545 (working days 7:00-15:00)

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