and high-tech

Distributor (authorized representative) to supply (deliver)

centrifugal pumps to industrial enterprises of Russia

Engineering company ENCE GmbH has been successfully working with different Russian industrial enterprises at the local market for many years having effected over 100 major deliveries of pump equipment to Russian plants.

Today our company is in search of pump equipment producers who consider Russian market attractive and want to boost their sales in the region, as well as expand their field of activities.

We are interested in cooperation with the manufacturers of centrifugal pumps, who are looking for official distributors (representatives) to supply their equipment to the industrial plants in Russia.

Advantages and principles of cooperation with ENCE GmbH:

The company’s employees are a solid team of higher-education professionals available for technical, commercial and legal support of cooperation with the industrial plants of Russia taking into account specifics and mentality of this country.

The company’s managers have a long-term successful track record of operation in the Russian market and extensive customer base, keep in touch with all the customers, frequently visit customer plants for early detection and replacement of obsolete equipment.

Commercial and engineering departments of the company are well-versed in the equipment of Russian industrial plants and know their up-to-date revamping and modernization needs.

Logistics department of ENCE GmbH is capable to deliver equipment on DAP or DDP terms at the discretion of its Russian customers.

Our service engineers are available for supervision and commissioning of pump equipment as well as warranty maintenance in strict compliance with the manufacturer’s recommendations.

ENCE GmbH arranges presentations regarding the latest achievements of its foreign partners - equipment manufacturers - for the staff of Russian plants.

Our company is closely cooperating with many engineering institutes of Russia, which gives us an opportunity to include your centrifugal pumps into prospective projects in different industrial fields.

As your official distributor of centrifugal pumps in Russia ENCE GmbH is responsible for the following:

  • drafting of required documents for participation in bidding procedures
  • technical and commercial negotiations with customers to agree on supplies of your equipment
  • entry into contracts for vortex pump deliveries
  • certification of different types of your pumps in accordance with Russian standards
  • expertise for obtaining local TR CU 010 and TR CU 012 certificates, which will enable your pumps to be used at all the industrial plants of the Customs Union countries (Russia, Kazakhstan, Belarus, Kyrgyzstan).
  • registration of delivery and subsequent customs clearance of centrifugal pumps, registration of transaction certificates for currency control purposes in Russian banks for payments in foreign currency in accordance with legislation of Russia and Customs Union countries.

Centrifugal pumps: description, characteristics and purpose

Centrifugal pumps are the type of equipment pumping water and producing the head by rotation of the impeller resulting in application of centrifugal forces.

The key elements of a centrifugal unit are as follows: the spiral casing and the impeller sat on the shaft. The shaft, in turn, rotates in bearings. Also, the pump design includes: the intake check valve with a mesh (it holds liquid in the casing and in the suction pipe while priming is carried out prior to the pimp run); the gate valve on the suction pipe; the vacuum meter (to measure rarefaction at the suction side).

The characteristics of centrifugal pumps are related to their design, materials used to make parts, and the principles of operation of major operating components. To find the pump characteristics with maximum accuracy, practical tests shall be carried out. Operation of centrifugal pumps is influenced by the vast number of external factors and impacts that cannot usually be covered completely in theoretical considerations.

With the same general operation principle, centrifugal pumps differ in terms of their design, sizes and capacity characteristics. As a rule, these differences exist for impellers and shaft position in the casing. The simplest of centrifugal pumps are single-stage pumps; these pumps are most common. The operating range for these pumps is wide in terms of water flow rate and pressure; however, these pumps produce relatively low water head.

Multistage sectional centrifugal pumps are more perfect. The design of these pumps includes several impellers and stages following each other. In such a case, water flow moves from one stage inlet to the next stage inlet, with the ultimate head being the total of heads produced by each stage in the system. The common shaft can be installed both vertically and horizontally. When you choose the centrifugal pump, please note that the pumps with the end seal of the shaft are more state-of-the-art than obsolete analogs with sealing glands. The major advantage of the former configuration is sustainable tightness and no leakages, as well as good tightness under vibrations and minor shaft movements.

Centrifugal pumps: classification

Centrifugal pumps: classification

The centrifugal pump design versions are as follows:

Single-stage centrifugal vertical or horizontal pumps: the shaft installed horizontally (standard design) or vertically (minimum size of a mounting pad)

Multi-stage centrifugal pumps: not one but several impellers are mounted in the pump casing, and this design is capable to produce much higher heads of pumped liquid at the pump discharge. Vertical and horizontal designs are available.

Semisubmersible centrifugal pumps: vertical design, with the pump volute and casing (partially) submerged into the pumped medium. These pumps are used for installation in sumps.

Submersible centrifugal pumps: the design with the pump and the motor integrated in a single sealed casing. The pump is submerged on a chain into the pumped medium completely. This pump is used to evacuate liquids from sumps and drain pits.

Double-entry centrifugal pumps with inline-type casings: pumps with a suction pipe and a discharge pipe aligned along the same axis. Vertical and horizontal designs are available.

Sealed centrifugal pumps: pumps made with sealed casing. Two versions are available. In the first version, the impeller is fastened on the motor shaft; in the second version, the magnetic clutch is used to couple the pump with the motor. In both versions, the pump casing is completely sealed, and no leakages are possible for pumped medium. This type of pumps is used predominantly in chemical industry for chemically poisonous, dangerous, toxic or highly volatile liquids.

Three major classifications of centrifugal pumps exist: by the design principle details; by the head level and the impeller speed; by the pumped liquid type.

  1. By the design principle details, the common types of centrifugal pumps are as follows. By the number of impellers, centrifugal pumps are classified into two types: with a single impeller (single-impeller) and with several impellers (multiple-impeller). In single-impeller (aka single-stage) pumps, cantilever-type shaft positioning is used; so, the term cantilever pump is also applicable to these pumps. Multiple-impeller (aka multi-stage) pumps have several impellers mounted one after another, increasing the equipment capacity. In terms of their design, centrifugal pumps may be made with a single-directional or double-directional water inlet, the shaft mounted horizontally or vertically, and the horizontal or vertical casing joint. Depending on the way used by the operating substance to enter the spiral passage, these pumps are classified into the spiral pumps (liquid is delivered into the spiral passage) and the turbine pumps (liquid flows initially through the static wheel with blades).
  2. By the head level and the impeller speed, centrifugal pumps are classified into the low head pumps, moderate head pumps and high head pumps, and into slow, high-speed and normal pumps.
  3. By the pumped liquid type, pumps can be classified into water supply units, sewerage units, units for acid liquids etc.

Centrifugal pumps: major components (elements)

The major components in centrifugal pumps are the spiral casing and the impeller mounted in the casing and fastened on the shaft by a key. The shaft rotates in bearings. Glands are used to seal the passage opening used for the shaft running through the casing. Liquid runs through the suction pipe into the pump casing and, subsequently, into the impeller center; the impeller rotates. The substance rotates, driven by the blades and thrown from the impeller center to the periphery, enters the spiral part of the pump casing (in spiral pumps) and flows in the pressure pipeline through the discharge pipe. In such a way, blades impact water molecules; as a result, the motor’s kinetic energy is transformed into the velocity head of the pressurized liquid jet.

Pumped substance column meters are the units of measurement used to measure the liquid jet head delivered by the pump. Liquid is sucked due to rarefaction in front of the impeller blades. Blades are convex-shape to make the liquid head ber and the flow smoother; the impeller rotates with its blades facing the discharge direction by their convex sides.

As a rule, the equipment and valves used in centrifugal pumps are as follows:

  • the intake check valve with a mesh to holds water in the pump casing suction pipe while the pump priming is carried out before activation. The mesh removes suspended particles from water;
  • the gate valve;
  • the vacuum meter used to read rarefaction at the suction side. It is installed at the pipeline between the casing and the gate valve. The centrifugal pump is also equipped with a tap used to bleed air while the priming is in progress (the tap is at the casing top) and a check valve installed on the pressure pipeline to prevent water from running back through the centrifugal pipeline if necessary;
  • the gate valve installed on the pressure pipeline. The gate valve initiates the process, stops it and controls the capacity of a heading produced by the centrifugal pump;
  • the pressure gage used to read the liquid head produced by the centrifugal pump. The manometer is installed on the pump discharge pipe;
  • the safety valve protecting the centrifugal pump against water hammers. This valve is installed on the discharge pipe behind the gate valve protecting the pump. Also, priming devices and various automation equipment units are often installed on centrifugal pumps.

Single-stage centrifugal pump drawing (standard schematic)

1. Spiral casing (the volute) with the suction pipe and the discharge pipe, standard version (the suction pipe is horizontal, the discharge pipe is vertical)
2. Impeller
3. Shaft sealing unit
4. Shaft
5. Labyrinth sealing for the bearing oil chamber
6. Bearing support unit
7. Load-bearing support unloading the shaft
8. Level gage eyehole used to monitor the oil level in the bearing unit chamber

Multi-stage centrifugal pump drawing (standard schematic)

Centrifugal pumps: operation principle

The centrifugal pumps principle of operation is based on centrifugal forces emerging in the pump casing during operation due to the impeller rotation. The key joint is used to fasten the impeller on the pump shaft; the torque, produced by the pump drive, is transferred from the shaft to the impeller. The elastic coupling is used to connect the pump shaft with the electric motor drive shaft.

Centrifugal pumps are the most common pipes used to move liquid substances.

Centrifugal pumps operate only when the unit casing is filled with water. These pumps are driven by the centrifugal force produced by the impeller rotation. One or several impellers are installed in the pump casing; they are rigidly fastened on the shaft. If several impellers are used, each impeller has convex blades connecting the pair of disks. Liquid enters through the suction pipe. Upon the unit activation, the shaft coupled with the electric motor is used to run an impeller. The impeller captures water and throws it from the impeller center to the periphery. Growing centrifugal force contributes to liquid movement into the discharge pipeline implemented by the guiding chamber. With the space emptying, pressure between the blades grows, allowing the new amounts of liquid to flow from the pipeline. Usually, the filter is installed in the suction pipe preventing the suspensions and debris from entering the pump casing. The principle of operation is similar for single-stage and multiple-stage pumps. The difference is that in multi-impeller pumps pressure grows at each next impeller.

Centrifugal pumps: advantages

The advantages of centrifugal pumps can generally be subdivided into design-related and function-related advantages.

As for their design, centrifugal pumps have small sizes due to the direct coupling that connects the unit itself with steam turbines and the electric motor. As a result, these units have small weight and dimensions, while their capacity is high and they require small room and relatively light foundation for installation. Centrifugal pumping units are easy to dismantle and install. They are reliable, have long service life, their operation is cost-effective, and their maintenance is easy.

Function-related advantages include the pump capability to be activated quickly and its easy adjustment. These pumps deliver water smoothly and continuously, because the hydraulic hammers are eliminated in the pressure pipeline.

Centrifugal pumps are widely used to pump substances containing suspended particles, debris or pollutants.

Relatively cheap materials, such as cast iron, polymers and steel, are used to make these pumps, resulting in their reasonable cost.

Centrifugal pumps: application in industry

Centrifugal pumps can work with water at any temperature, highly-viscous liquids, waste water, substances containing various admixtures (such as sand, slag, soil, peat or coal). Therefore, these pumps are widely used in chemical and petroleum industry, at mines and in utilities.

Centrifugal pumps intended for operation with water are used for heating systems, in cooling and conditioning plants. These models of pumps provide continuous circulation of liquid in a closed loop to keep the constant temperature. These types of pumps are often used at household land plots.

Submersible pumps are used to evacuate clear or moderately contaminated water. These pumps are used to extract clear water from a well or a borehole, or to remove water from flooded rooms. A submersible pump can operate continuously over a long time.

A self-suction pump is actively used as a component of a pumping plant. This pump can be used for any work involving liquids with a very wide range of contamination levels.

Centrifugal pumps are used quite intensively in petrochemical plants, in chemical processing, and in food industry.

Centrifugal pump application: more information

Centrifugal pumps: operation and service life extension

The specific set of instrumentation must be installed on centrifugal pumps to ensure their trouble-free operation.

To protect the pump impeller against debris that can accidentally occur in the pipeline with pumped medium, a gate valve and a filter should be installed at the pump inlet line.

To prevent cavitation resulting from the pumped medium outflow, a check valve and a pressure gage should be installed to control the flow pressure at the pump inlet.

To prevent possible hydraulic hammer resulting from the closed gate valve at the discharge line, a check valve and a pressure gage should be installed immediately downstream from the pipe to control pressure produced by the pump.

When you select a centrifugal pump from the range of sizes, choose a pump with the major operating characteristics (capacity and head) corresponding to the middle of the operating range on the plots of curves describing the major operating characteristics for the chosen series.

When you select the pump dimensions, consider the maximum values of the required major characteristics, such as the capacity and head levels required to be provided by the pump, and pay attention to the resistance of the system in which the pump will be installed.

For effective trouble-free pump operation, cavitation must be prevented. For this purpose, the condition as follows must be observed: for the pump, the positive suction head must be less than the positive suction head of the system in which the pump is installed.

The materials for the pump flow channel and for the pump parts operating in contact with the pumped medium must be chosen, taking into consideration the corrosiveness of pumped medium.

For materials chosen correctly, the permissible corrosion rate in the pump flow channel is ≤0.1 mm/year.

For chosen steel, the corrosion rate in the pump flow channel must be less than 0.1 mm/year.

The design and type of sealing unit used in the pump shall be chosen in accordance with physical and chemical properties of liquid moved by the pump. Gland seals or various types of mechanical seals can be used in centrifugal pumps.

Use the plots of major pump operating characteristics (for maximum capacity) to find the pump power consumption.

Typically, such plots exist for water; if the density of pumped liquid differs from that for water, the pump power consumption resulting from the plot must be multiplied by the pumped liquid to water density ratio.

Motors for centrifugal pumps: how to select and calculate the motor parameters

Motors for various types of centrifugal pumps shall be chosen in accordance with the density of a medium to be pumped.

The required motor power shall be calculated as follows: Nmotor=KN(Pliquid/1000),

N is the pump power consumption;
Pliquid is the pumped liquid density;
Nmotor is the motor power;
К is the safety factor assigned in accordance with the motor power:
<4 kW: К=1.3;
4…20 kW: К=1.25;
20…40 kW: К=1.2;
>40 kW: К=1.15.

In accordance with the resulting power, the nearest greater size from the range of motor sizes shall be chosen.

Various types of motors can be used for centrifugal pumps. AC electric motors and diesel motors are standard solutions. The version of design of the electric motor installed in the pump depends on the safety classification of the room in which the pumping unit shall be installed.

A clutch, a reducing gear, a multiplying gear or a V-belt drive is used to couple the centrifugal pump and the motor.

We are convinced that our company ENCE GmbH will become your reliable and efficient distributor (authorized representative) of your centrifugal pumps in the Russian market.