Essential advantages of type G deep-well pumps
- the pump unit may be installed in a suspended, standing or horizontal position without necessity to rebuild foundations
- may be installed in drilled, small-diameter wells without suction jackets
- may be installed in drilled, large-diameter wells and in large tanks, with the use of suction jackets
- pump unit may be installed directly in the pipeline, in a hermetic jacket in a vertical or horizontal position
- may be incorporated with the pump unit by-pass in parallel to the pipe line, in a hermetic jacket in a vertical or horizontal position
- incorporation of the pump unit is simplifi ed by the linear position of stub pipes in the hermetic jacket
- space requirement is minimized due to compact design
- standardized design of the connections and couplings of the pumps and motors according to NEMA, which is accepted and used by all deep-well pump manufacturers in the world
- a splined slide-over coupling enables torque to be transferred effi ciently and durably without any maintenance, for a simplifi ed assembly/disassembly/replacement and facilitated servicing
- the pump/motor bearing arrangement requires no maintenance, it is lubricated by the pumped liquid in the pump and by the liquid that fi lls the motor in the motor, which enables heat of energetic losses to be removed therefrom
- the pump unit, submersed in a hermetic jacket or tank, produces no noise
Deep-well pumps are designed for use in handling raw or treated potable water, sea water, as well as for mineral and thermal applications, with no long fi bers or abrasive content.
Mechanical impurities in the liquids handled may be up to 100 mg/l of water; for pump units where impellers and stators are made of plastic, they may be up to 50 mg/l of water.
Impurities that might cause creation of deposits in the pump and on the motor are inadmissible. If this is unavoidable, the deposits of 0.5 mm maximum must be removed.
Liquids liable to cause accelerated corrosion or erosion of the pump construction materials must never be used.
Liquids other than water may be handled subject to manufacturer’s approval.
- Capacity Q: 0,9 ÷ 420 m3/h
- Delivery head H: up to 642 m
- Liquid maximum temperature t: up to 25oC*
* for higher temperatures, please contact the manufacturer every time
Motors used in deep-well units
Deep-well pumps manufactured by Hydro-Vacuum S.A. are fi tted with wet-type submersible electric motors.
Other types, ones having a fl ange connection and dimensions according to NEMA, may be used, if required.
Cooperation with frequency converters
All deep-well units manufactured by Hydro-Vacuum S.A. and equipped with three-phase electric motors may have a frequency converter drive. Recommendations:
- avoid operation of submersible motors at higher than nominal frequencies, i.e. 50 and 60 Hz;
- the power rating of the submersible motor selected ought to be one magnitude higher than the standard motor power rating, matching a given pump;
- the permissible minimum frequency is 32Hz, provided that a minimum rate of fl ow past the external motor surface of 0.2 m/s is maintained; it is advised to use a suction jacket for the purpose;
- use RC and LC fi lters to protect the motor from harmful over-voltage and interferences;
- select a frequency converter that matches the nominal current rating of the motor;
- the frequency converter ought to incorporate safety devices, protecting the motor from:
- drop of supply voltage,
- phase decay.
- the frequency converter ought to be supplied strictly in accordance with manufacturer’s requirements, specifi cally those in respect of feeder-cable cross-sections and keeping the permissible distance between the frequency converter and the motor.
- please note that the relationship below applies when changing the current frequency / rate of rotation of the pump unit shaft
For details of the cooperation between deep-well pumps and frequency converters please contact our Technical Advisors Department.
General conditions of characteristics validity
For all the characteristics of the pumps shown in this catalogue the following general conditions shall apply:
- the characteristics declared above refer to pump units, with motors supplied with electric current at 50 Hz and power output suffi cient for the entire pump capacity range
- tolerances of pump operation parameters according to PN-EN ISO 9906 Cl. 2 Appendix A
- the characteristics are obtained for handling non-aerated water at 20°C and viscosity v = 1 mm2/s
- the pump characteristics H=f(Q) include hydraulic losses at the pump inlet and the non-return valve which is built in the pump
- power characteristics P=f(Q) show an average power consumption by a single pump stage
- effi ciency characteristics η=f(Q) refer to a single hydraulic stage of a pump with a nominal-diameter impeller; without taking into account any losses at the pump inlet and the non-return valve
- the pump effi ciency for several stages or with trimmed impellers is lower than that shown in this catalogue and the effi ciency characteristics η=f[Q] may be provided by the manufacturer if requested by the client
- the pump works without cavitation if the required NPSH cavitation reserve plus the liquid column 0,5-1m is maintained
- for handling liquids other than water please contact the manufacturer: handling liquids of which the density and viscosity are higher than those of water will cause an increased requirement for power at the pump shaft , therefore, a motor with a higher power output has to be used.
In certain situations, the duty point required may be located between the nominal characteristics of the succeeding pump type dimensions. Th erefore, intermediate characteristics, obtained by the nominal impeller trimming, are introduced in GC, GD and GF deep-well pumps. In the GC and GD pumps having up to 9 stages, the succeeding trimmings are denoted by the letters A, B, C… and in the GF pump the succeeding impeller trimmings are denoted by the digits 1 to 5. Th is enables an optimized selection of the pump unit to match the required operating parameters, reduces power requirement on the pump shaft and enables a motor with a lower nominal power output to be selected.
If you are interested in pumps with more than 9 stages and having trimmed impellers, please contact the pump unit manufacturer. It is recommended to select pumps for operation in their high performance range for a more economical operation and maximized service life of the pump unit.
Th e pump unit may not be operated with the valve on the discharge pipe closed because the absence of fl ow past the motor makes it impossible to cool it. Th e recommended minimum pump capacity is not lower than 0,2*Qmax.
Design of deep-well pumps
Deep-well pumps are a multistage type of pumps, constructed in series. Th ey are installed on submersible motors, therefore, they are also referred to as submersible units. Th e pumping unit is installed vertically, with a submersible motor located at the bottom and the deep-well impeller pump. Th e suction casing, protected with a sieve fi lter, is installed straight on the motor. Th e specifi c pump stages are installed aft er the suction casing. Each of them comprises the casing and the stator fi tted in it, and an impeller (radial or diagonal type). Th e pump is closed with the non-return valve housing and the discharge casing to connect the pump unit to the discharge pipe using either fl anges or a threaded connection. A coupling is provided to connect the rotating parts of the pump and the motor shaft . Distance sleeves are provided to correctly position the impeller in the stator and pump casing.
Th e rotating unit of the pump has steel-and-rubber bearing bushes.
Depending on the deep-well pump type, the pump stages may be connected using either:
- connecting tapes (the GAB, GB, GBC, GC and GCA pumps), or
- double-nutted bolts (the GDB, GDC and GFB pumps) - individual stages.
Underwater deep-well units are special application pumps. Th ey are compact and highly reliable. Th ey have the following advantages:
- low cost (the bore-holes have very small diameters, no buildings over the well are required),
- low operating costs,
- simple operation (no lubrication points),
- fast and simple assembly and disassembly.
Deep-well pumps have been manufactured by HYDRO-VACUUM S.A. since 1939. Experience and ongoing improvement eff ort have resulted in a series of deep-well pumps of which the operating characteristics and service life are comparable to those of European products. Th ey are used in a number of applications all over Poland: in municipal drinking water systems, in villages, in housing estates, in farming and gardening. Th ey proved very well in tests and have been operated on a regular basis in the brown coal strip mine in Bełchatów and Konin (Poland). At present, they are used in other strip mines and in the construction industry, where low subsoil water levels are required in deep foundation trenches.