Labyrinth seals have been used since 1990 to reduce the flow of compressible fluid between rotating and stationary elements of centrifugal compressors, blowers, turboexpanders, steam and gas turbines and other equipment.
They are used as interstage, intersectional, end seals, as well as seals of unloading devices and are designed for specific operating parameters.
Meets the requirements of API 617 standard
Thrust lever bearings (PUR) are used in centrifugal compressors, gas compressors, steam and gas turbines, generators, pumps and other equipment.
Meets the requirements of API 617 standard
Bearings are designed and supplied to order for specified installation dimensions and operating conditions, both non-reversible and reversible with non-reversible properties. The existing range of bearings covers a load bearing range of up to 60,000 kgf.
Since 1990, damper bearings have been successfully used in the most critical compressors, turbines, gas compressor units, pumps, and multipliers with high reliability requirements.
Meets the requirements of API 617 standard.
The existing range of bearings covers a range of shaft diameters from 40 mm to 500 mm with rotor speeds from 1,500 rpm to 40,000 rpm.
By agreement with the customer, it is possible to develop and manufacture a bearing that differs from the existing series for specified geometric parameters, load-bearing capacity and rotor speed.
Support bearings are the most important components that ensure the stability of rotor rotation in modern high-speed machines: compressors, gas turbines, turbogenerators, multipliers, pumps, etc. In critical positions, it is important to use bearings that can not only withstand self-excited vibrations, but also dampen vibrations for stable expansion working range.
One of the activities of SNT Slovakia s.r.o. is the manufacture and supply of spare parts for gas pumping and turbocompressor units (GPA and TKA), with a capacity from 6.3 to 25 MW with gas turbine and electric drives, used at oil and gas and energy industry facilities in the CIS countries, near and far abroad (including Ukraine, Uzbekistan, Turkmenistan, Kazakhstan, Turkey, Iran, Bulgaria, Argentina), as well as centrifugal gas compressors operated as part of such units.
Possessing production, scientific and technical potential, our partners can manufacture and supply the customer with the required products in the shortest possible time, as well as provide technical consulting support to the customer during the operation of the products.
– Frames of pumping units
– Various types of couplings and components for them: gear, sleeve-pin, cam, plate.
– Oil seal kits
– Mechanical mechanical seals and spare parts for them (rubber products, friction pairs, hardware)
– Kits for converting (upgrading) pumps from gland seal to mechanical mechanical seal and vice versa
– Sliding bearings (liners)
– Rolling bearings (GOST or manufactured in Europe, Japan)
– Bearing housings of various types (rolling, sliding): for bearings with grease lubrication; for crankcase-type lubricated bearings with lubricating rings; for bearings with forced lubrication from an external source)
– Axle boxes for oil seals
– Flanges, gaskets and fasteners
– Shut-off and control valves, fittings, adapters (check valves, control valves, throttling devices, etc.)
– Oil stations and parts of oil stations (oil tanks, oil filters, oil supply pumps, oil coolers, etc.)
Our company has the opportunity to purchase parts for the stator group of pumps, including:
For parts and assemblies operating under pressure, hydrostatic tests are performed in accordance with the requirements of current regulatory documentation.
The production of spare parts is possible both according to the documentation of the original manufacturers and according to the Customer’s documentation.
All products are provided with a manufacturer’s warranty of at least 12 months.
Our company supplies parts for rotary pumps, including:
Upon delivery the following is produced:
The production of spare parts is possible both according to the documentation of the original manufacturers and according to the Customer’s documentation.
All products are provided with a manufacturer’s warranty of at least 12 months.
Network pumps are designed to supply hot water through heating networks. The main parameters of the pumps were regulated by GOST 22465-77.
Depending on the installation location, they are used as pumps:
– the first rise, supplying water from the return pipeline to the heaters;
– second rise to supply water after the heaters to the district heating network;
– recirculation installed after hot water boilers.
Basic requirements for the design of network pumps:
– work under conditions of significant fluctuations in temperature and pressure;
– stable, continuously decreasing shape of the pressure characteristic in the flow range of 20-110% of the nominal, ensuring reliable parallel operation.
Network pumps must operate reliably over a wide flow range. Changing the parameters of individual types of pumps can be achieved by trimming the impellers along the outer diameter within the limits specified by the manufacturer. The reduction in efficiency should not exceed 3%.
Since the temperature of the pumped water varies within 120-180 °C, the design of network pumps, unlike general-purpose pumps, ensures free thermal expansion of the pump elements, and the rotor end seals have a cooling system (thermal barrier), like other “hot” pumps.
Depending on the pressure created, network pumps can be one- and two-stage spiral type with a horizontal connector, with double-entry impellers (type D), with synchronous rotation speeds of 1500 and 3000 rpm.
Depending on the size, they can be supplied on either a common or separate foundation slab.
The materials of the main parts of network pumps are gray cast iron and chromium steel.
As examples of design, let’s consider network pumps SE 500-70-16 and SE-1250-140-11.
The basic part of the pump is a housing with a horizontal split in a plane passing through the axis of the pump. The pump casing is a cast iron casting of complex shape, consisting of two parts (pump cover and pump body), in which semi-spiral inlet and double-spiral outlet channels are cast, as well as chambers (thermal barriers) for supplying and discharging coolant to the end seals. Inlet and discharge pipes, support legs and trough-shaped brackets for collecting leaks, as well as mounting the bearing housing, are also cast in the lower part of the housing. The location of the inlet and discharge pipes in the lower part of the housing makes it possible to disassemble the pump without dismantling the pipelines. The pipes are directed horizontally in opposite directions. The horizontal connector is sealed with a paronite gasket. The studs on the connector are tightened with cap nuts to prevent hot water from seeping through the threads of the studs. The housing with four legs, the supporting surfaces of which are as close as possible to the axis of the pump to reduce misalignment when the pump heats up, rests on the pedestals of the foundation frame. To ensure directed thermal expansion of the pump, pins are installed in the lower part of the housing, acting as guide keys. In the upper part of the pump housing (cover) there is a plugged hole for air release. In places where the impeller is sealed in the pump housing, sealing rings are installed.
The pump rotor is an independent unit and consists of a shaft, impeller, oil seal bushings, left bushing, right bushing and fasteners. The impeller consists of two halves and is mounted on the shaft using a sliding fit. Torque is transmitted to the impeller using a key. From axial movements, the impeller is fixed on the shaft by left and right bushings. The oil seal bushings are secured against axial movement with set screws. To compensate for thermal expansion of the rotor parts, thermal gaps are provided between them. The rotor is statically balanced after assembly.
The rotor is relieved from axial forces by using a double-entry impeller.
The shaft seal is stuffing box type. In order to ensure the temperature regime in the stuffing box, coolant is supplied and discharged to the thermal barriers. To unload the seal, an annular throttling slot is made in front of it. Leaks through the stuffing box are collected in a trough and discharged to the drain.
It is possible to install mechanical seals.
The pump rotor is supported by rolling bearings, which are installed in split housings. The support bearing on the drive side absorbs radial loads. The thrust bearing on the side of the free end of the shaft absorbs residual axial forces and radial loads. Bearings are lubricated with liquid, ring (crankcase) lubrication using a spray disc. Oil level indicators are provided to monitor the oil level. The bearing housings are equipped with chambers for water cooling.
Aligning the rotor with the stator carried out by moving the bearing housings with adjusting screws. After final alignment, the bearing housings are fixed relative to the pump housing with tapered pins.
Within the pump there is a system of auxiliary piping for cooling the rotor end seals and bearing units.
An asynchronous motor with a squirrel-cage rotor is used as a drive.
The pump and motor are connected to each other using an elastic pin-sleeve coupling. The coupling is closed by a guard.
The symbol of the pump means: SE – network electric pump; 500 – flow rate in m3/h; 70 – head in m; 16 – inlet pressure in kgf/cm2.
Figure 1
The basic part of the pump is a housing with a horizontal split in a plane passing through the axis of the pump. The pump casing is a cast iron casting of complex shape, consisting of two parts (pump cover and pump body), in which the channels of semi-spiral inlets and spiral outlets are cast. Inlet and discharge pipes, support legs and trough-shaped brackets for collecting leaks, as well as mounting the bearing housing, are also cast in the lower part of the housing. The location of the inlet and discharge pipes in the lower part of the housing makes it possible to disassemble the pump without dismantling the pipelines. The pipes are directed horizontally in opposite directions. The horizontal connector is sealed with a paronite gasket. The studs on the connector are tightened with cap nuts to prevent hot water from seeping through the threads of the studs. To supply water from the first to the second stage of the pump, a transfer pipe is provided in the upper part of the housing (lid). To reduce leaks, a diaphragm is installed between the stages. There are holes for air release in the upper part of the transfer pipe and the pump housing (cover), and holes for draining water from the pump in the lower part of the pump housing. When the pump is running, the holes are closed with plugs. To reduce possible vertical temperature movements of the housing, the supporting surfaces of the feet are as close as possible to the axis of the pump and with them the pump rests on the pedestals of the foundation frame. To ensure directed thermal expansion of the pump, pins are installed in the lower part of the housing, acting as guide keys. In places where the impellers are sealed in the pump housing, sealing rings are installed.
The pump rotor is an independent unit and consists of a shaft, impellers, protective sleeves, bushings, bearing sleeves, oil deflectors and fasteners. Double-entry impellers, mounted on the shaft using a sliding fit, rest against protective bushings and are fixed axially through the oil seal bushings with round nuts. To compensate for thermal expansion of the rotor parts, thermal gaps are provided between them. The rotor is dynamically balanced after assembly. The rotor is relieved from axial forces by using double-entry impellers.
The shaft seal is an stuffing box type with cooling. In order to ensure reliable operation of the gland seal, gland bushings are installed in the pump housing, forming chambers (thermal barrier) into which coolant is supplied. The coolant supplied to the oil seal is divided into two streams. One flow washes the outside of the stuffing box and is discharged into the drain pipeline, the other flow through the hole in the stuffing box enters the lantern ring and is supplied to the packing. Leaks through the stuffing box are collected in a trough and discharged into the leakage pipeline. The design provides for unloading of the second stage gland by draining water from the gland through the unloading pipe into the first stage inlet. Leaks through the stuffing box are collected in a trough and discharged to the drain.
It is possible to install mechanical seals.
The pump rotor is supported by rolling bearings, which are installed in split housings. The bearing housings are made of two halves with a horizontal split. A roller bearing is installed in the support bearing housing on the drive side, which absorbs radial loads. In the thrust bearing housing, on the side of the free end of the shaft, two angular contact ball bearings are installed, which absorb residual axial forces and radial loads. Bearings are lubricated with liquid, ring (crankcase) lubrication using lubricating rings. Oil level indicators are provided to monitor the oil level. There are chambers in the bearing housings, and also refrigerators are installed into which coolant is supplied to cool the oil.
Alignment of the rotor with the stator is carried out by moving the bearing housings with adjusting screws. After final alignment, the bearing housings are fixed relative to the pump housing with tapered pins.
Within the pump there is a system of auxiliary piping for cooling the rotor end seals and bearing units.
An asynchronous motor with a squirrel-cage rotor is used as a drive.
The pump and motor are connected to each other using an elastic pin-sleeve coupling. The coupling is closed by a guard.
The symbol of the pump means: SE – network electric pump; 1250 – flow in m3/h; 140 – head in m; 11 – inlet pressure in kgf/cm2.
Figure 2
Condensate pumps of the Ks, KsD, KsV types represent a special group of energy pumps characterized by specific operating conditions: operation in conditions of high vacuum and minimal geometric head. This margin is determined by the difference in the vertical marks of the level of the free surface of the liquid in the condenser and the center of gravity of the inlet opening of the impeller of the first stage of the pump (geometric support) and losses in the inlet path of the pump.
Condensate pumps are designed for pumping condensate in steam-water networks of thermal power plants operating on fossil fuels, as well as liquids similar to condensate in viscosity and chemical activity. The main parameters of the pumps were regulated by GOST 6000-88.
Condensate pumps are divided into pumps of the first and second lifts of the main condensate and drainage ones. The first lift pumps pump condensate from the turbine condenser through a block treatment plant to the inlet of the second lift pumps, which supply the condensate through low-pressure heaters to the deaerator.
Condensate pumps must operate reliably in the presence of initial or developed stages of cavitation in the impeller area, and in some cases, in the presence of supercavitation flow around the impeller elements.
The specific operating conditions of condensate pumps determined the basic requirements for their design:
– ensuring reliable and long-term operation (at least 10,000 hours) with partial cavitation in the pump;
– absence of air leaks through operating and idle pumps;
– a stable, continuously decreasing form of the pressure characteristic in the supply range from 20% to 110% of the nominal to ensure stable parallel operation in the general network.
To expand the range of use of condensate pumps, it is allowed to trim the impellers along the outer diameter by no more than 10% of its original value. In this case, the reduction in efficiency should not exceed 3%.
In order to reduce the harmful effects of cavitation and ensure reliable operation of condensate pumps, the following operating times in the flow ranges are recommended:
– from 0 to 0.2Qnom – no more than 3 minutes;
– from 0.2 to 0.5Qnom – up to 5% of the total pump operating time;
– from 0.5 to 0.85 Qnom – no more than 15% of the total pump operating time;
– from 0.85 to 1.05Qnom – without limitation
– over 1.05 Qnom – according to the load conditions of the electric motor and the cavitation reserve at the input.
All manufactured condensate pumps can be combined into several structurally similar groups. Within each group, pumps have many common design features and solutions with minor differences in the design of individual components.
The materials of the main parts of condensate pumps are gray cast iron, carbon and alloy steels. Chromium steels are used for first-stage impellers and pre-engaged axial wheels.
For small flows, Ks type pumps are used.
As an example of a design of this type, consider the condensate pump Ks 32-150-2.
Condensate pump Ks 32-150-2 (Figure 1) – centrifugal, multistage, horizontal, sectional type with one-sided impellers.
Figure 1
The pump body consists of inlet and discharge covers, between which a set of standardized sections is installed.
One section includes a guide vane, which performs the functions of supplying fluid to and removing it from the impeller, and the section housing. In places where the impellers are sealed in the sections and guide vanes, replaceable sealing rings are installed.
The package of sections and covers are centered together on cylindrical grooves and tightened with pins, forming a pump housing. The tightness of the joints is ensured by the “metal” contact of the sealing bands of the sections and covers, as well as by the installation of rubber sealing rings made of heat-resistant rubber.
The inlet and discharge covers are made of cast parts. Together with the covers, pipes and support legs are cast, with which the pump is installed on the base slab pedestals. The pressure pipe is directed vertically upward, and the inlet pipe is directed horizontally to the side (to the right of the horizontal axis of the pump, when viewed from the drive side). The design of the pipes is flanged. To remove vapors and release air, there is a hole in the upper part of the inlet cover. When the pump is running, the hole is closed with a plug. The pressure cover has a threaded hole for connecting the discharge drum chamber to the inlet pipeline.
End seal housings and bearing housings are attached to the covers.
To ensure directed thermal expansion of the housing along the pump axis, the lower part of the covers is provided with: a longitudinal keyway in the inlet cover, and a hole for installing a pin in the discharge cover.
The pump rotor is a separate assembly unit and consists of a shaft, impellers, an upstream wheel, a discharge drum, bushings, sealing parts and fasteners. To increase the suction capacity of the pump in front of the first stage impeller a pre-engaged wheel is installed. The parts are installed on the shaft using a sliding fit. All impellers, except the first stage, have the same flow path. The impellers, the upstream wheel, the discharge drum, and the bushings are fixed on the shaft with keys, and in the axial one with round nuts. There is a gap between the last stage wheel and the drum, which serves as a compensator for thermal expansion when the impellers are heated by the pumped condensate.
The assembled pump rotor is dynamically balanced.
The axial force of the rotor is perceived by the unloading piston (drum).
The end seals of the pump are stuffing box type with a water seal ring, to which cold condensate is supplied under pressure to cool the stuffing box and prevent air from leaking into the pump. The stuffing box is also cooled by cold condensate entering the chamber made between the seal housing and the bushing.
It is possible to install mechanical seals.
The rotor supports are rolling bearings with grease lubrication. A roller bearing is installed at the end of the shaft on the drive side, and a ball bearing at the free end of the shaft. The inner races of the bearings are fixed on the shaft with round nuts, the outer races with the end caps of the bearing housing, which are secured with through bolts. Tubes are provided in the bearing housings to drain leaks from the end seals.
Alignment of the pump rotor in the stator (pump body) is ensured by moving the bearing housings using adjusting screws. After the rotor is aligned, the position of the bearing housings is fixed with pins.
The pump housing is covered with a protective and decorative casing made of sheet metal, which is attached to the inlet and discharge covers.
An asynchronous motor with a squirrel-cage rotor is used as a drive.
The pump and motor are installed on a common foundation frame and connected to each other using an elastic pin-type coupling. The coupling is closed by a guard.
The pump symbol means: Ks – condensate; 32 – flow rate in m3/h; 150 – head in m; 2 – second modernization.
With increasing parameters of condensate pumps, mainly supply, their dimensions and weight increase. Due to the convenience of layout and reduction of the occupied space, in domestic practice, condensate pumps of thermal power plants with a flow rate of 200 m3/h and higher are manufactured in a vertical version of the KsV type.
The vertical design not only saves space, but also provides the maximum possible head pressure according to the installation conditions and the most favorable cavitation conditions, since the first stage impeller is located at the lowest point of the pump. In addition, this arrangement makes it possible to eliminate the shaft seal and external bearing on the suction side, replacing them with an internal bearing that operates on the pumped liquid.
Also, to ensure acceptable mass and dimensional characteristics of the pumps, they are designed at a relatively high rotation speed for condensate pumps, which in turn required the creation of first-stage working bodies with high suction capacity. For this purpose, pre-engaged axial wheels or double-entry wheels are used for the first stage.
As a rule, most domestic vertical condensate pumps have a double-casing design with one external sealing joint.
A distinctive feature of pumps of this type is that they can be assembled and disassembled without disconnecting the pipelines, and it is also possible to rotate the suction pipe relative to the vertical axis, which facilitates the placement of the pump unit.
The materials of the main parts of vertical condensate pumps are gray cast iron, carbon and alloy steels. Chromium steels are used for first-stage impellers and pre-engaged axial wheels.
As an example of the design of KsV type pumps, consider the KsV 320-160-2 condensate pump.
Condensate pump KsV 320-160-2 (Figure 1) – centrifugal, vertical, double-casing, multi-stage, sectional type internal casing with single-sided impellers.
The basic part of the pump is the outer casing, which is a welded structure and consists of two parts: receiving and pressure. The inlet and pressure pipes are welded to the outer casing and are located horizontally in opposite directions (at the Customer’s request, an option in one direction is possible). Also welded to the upper part of the housing are the pump support feet with stiffeners, in which there are holes for transporting the pump. In the receiving part of the outer casing of the pump there is a threaded hole for removing vapors into the air space of the condenser during startup and operation of the pump.
The inner housing (removable part) is a separate assembly unit consisting of the following components: rotor, end seal, thrust bearing and parts: pressure cover, section housings with guide vanes, supply to the first stage. The parts of the inner body are centered among themselves on cylindrical sharpenings and connected to each other with tie rods. The joints are provided with seals made of heat-resistant rubber rings.
Seal rings for impellers are installed in the section bodies, and interstage seal rings are installed in the guide vanes.
In the inlet to the first stage there is a sliding bearing on the pumped liquid.
The support lantern of the electric motor, the stuffing box seal housing and the thrust bearing are attached to the pressure cover.
To remove the inner housing, two eye bolts are provided in the pressure cover.
The joint between the pressure cap and the outer casing is sealed with a ring made of heat-resistant rubber.
The separating joint between the receiving and pressure parts is sealed with two rings made of heat-resistant rubber.
The pump rotor is a separate assembly unit and consists of a shaft, impellers, an upstream wheel, a discharge drum, bushings, sealing parts and fasteners. To increase the suction capacity of the pump, an upstream impeller is installed in front of the first stage impeller. The parts are installed on the shaft using a sliding fit. All impellers, except the first stage, have the same flow path. The impellers, the upstream wheel, the discharge drum, and the bushings are fixed on the shaft with keys, and in the axial one with round nuts. There is a gap between the last stage wheel and the drum, which serves as a compensator for thermal expansion when the impellers are heated by the pumped condensate. The shaft is also equipped with bushings with a special screw thread for supplying condensate to the lower and oil to the upper bearings.
The assembled pump rotor is dynamically balanced.
The axial force of the rotor is perceived by the unloading piston (drum), which ensures almost complete balancing only at nominal feed. When the operating mode deviates from the nominal one, an unbalanced force acts on the rotor, which can be directed downward or upward depending on the pump flow and is perceived by two angular contact bearings
nicknames The unloading drum is mounted on a common key with the impeller of the last stage and is fixed in the axial direction with a round nut. To prevent water leakage under the drum along the shaft, a sealing ring made of heat-resistant rubber is installed.
To connect the chamber behind the unloading drum with the supply pipeline of the pump, a unloading pipe with a connecting flange is installed on the stuffing box housing and brought out.
The end seal of the pump is of the gland type with a water seal ring, to which cold condensate is supplied under pressure to cool the stuffing box and prevent air from leaking into the pump. Cold condensate is supplied from the cooling cavity of the seal housing through the holes to the water seal ring. The seal is accessible through windows in the bearing housing.
It is possible to install mechanical seals.
The rotor is supported by two bearings. The upper thrust bearing is made of two angular contact ball bearings installed in an X-shaped pattern and fixes the position of the rotor in the pump, and also perceives radial and residual axial forces. Bearing lubrication is liquid. The design of the upper pump support provides a circulating lubrication system for the bearings. An oil bath is made in the bearing housing, from which oil is supplied through a special hole to the bearings using a screw-threaded bushing. The used oil is drained by gravity into the bath through holes made in the bearing housing. Oil cooling is carried out using a coil, the spiral section of which is located in the oil bath, and the straight sections pass through vertical holes in the bearing housing and form branch pipes for supplying and discharging process water. The oil level in the bath is controlled by the oil level indicator. To drain contaminated oil, there is a special device in the lower part of the oil bath, which is an elbow covered with a cap. In the middle part of the bearing housing there is a threaded hole, closed with a plug, for filling oil. Next to the oil filling hole there is a hole connecting the oil bath to the atmosphere. To control the temperature of the bearings, there is a place on the housing for installing a resistance thermal converter.
The lower journal bearing is lubricated by the pumped condensate, which is supplied from a specially designed chamber to the bearing by a bushing with a multi-thread and, after passing through a gap, is discharged into the suction cavity. The bearing clearance is adjusted using set screws, after which the bearing sleeve is pinned. To protect against the ingress of solid particles, the bearing is covered with a mesh.
Alignment of the pump rotor in the stator (inner pump housing) is ensured by moving the bearing housing using adjusting screws. After aligning the rotor, the position of the bearing housing is fixed with pins.
An asynchronous motor with a squirrel-cage rotor is used as a drive. The electric motor is installed on the pump lantern and connected to it with an elastic sleeve-pin coupling. Alignment of the electric motor and pump is carried out by moving the lantern using adjusting screws. After centering, the position of the lamp is fixed with pins.
The pump symbol means: KsV – condensate vertical; 320 – flow rate in m3/h; 160 – head in m; 2 – second modernization.