Masdaf – OMKV vertical multistage pump with a head of up to 400 m
The OMKV multistage pump is a vertical centrifugal pump of the sectional type with split stage casings, designed for an operating pressure of 40 bar. The series has a flow rate of 5 to 180 m³/h, a head of 30 to 400 m, and a speed of 1,500 to 3,600 rpm. The pump is not self-priming and operates with clean or slightly contaminated liquids at temperatures ranging from 0 to 110 °C.
What applications is the OMKV series designed for?
The OMKV covers the high-pressure niche with a low flow rate: 400 metres of head at a flow rate starting from 5 m³/h. This is a typical requirement for pressure-boosting systems in high-rise buildings, boiler feed systems, high-pressure washing systems and industrial water distribution systems, where it is the pressure, rather than the volume, that is important. The vertical design also allows the pump to be installed in a confined space: the unit occupies an area close to that of its own flange.
How to interpret model codes
The notation is based on the following scheme OMKV 40 / 8, where OMKV is the series designation, the first number is the nominal diameter of the pressure flange in millimetres, and the second is the number of stages. In other words, OMKV 40/8 has a DN 40 pressure flange and eight stages.
How is the axial force balanced, and what does the rotor rest on?
The axial force from the wheel assembly is counteracted by balancing holes in each working wheel. Any residual unbalanced force is absorbed by the bearings. The bearing arrangement is asymmetrical: at the top, on the discharge side, there is a 6400 C3 series ball bearing with grease lubrication — this is what bears the axial load; at the bottom, on the suction side, there is a Teflon-coated bronze plain bearing, which is lubricated by the pumped fluid. This imposes a practical limitation: dry starting is not permitted for this series.
OMKV Technical Specifications
| Parameter | Value |
|---|---|
| Type | vertical, multistage, centrifugal, sectional-type pump, non-self-priming |
| Working pressure | 40 bar |
| Capacity | 5 – 180 m³/h |
| Pressure | 30 – 400 m |
| Rotational speed | 1,500 – 3,600 rpm |
| Suction flange | DN 50 – DN 125, DIN 2535 (PN 40) |
| Discharge flange | DN 32 – DN 80, DIN 2535 (PN 40) |
| Fluid temperature | 0 – 110 °C |
| Impellers | single-flow, closed, dynamically balanced, with the option of machining to the operating point |
| Balancing the axial force | balancing holes; the residual force is absorbed by the bearings |
| Bearings | Ball bearing 6400 C3 with grease lubrication at the top, on the discharge side; bronze plain bearing with a Teflon coating at the bottom, on the suction side |
| Wear rings | option |
| Drive | an electric motor mounted on a common base via a flexible coupling |
| Direction of rotation | By default, clockwise from the drive side; other options are available |
| Certification | CE; TSE ‘Centrifugal Pump’, Classes 1 and 2 |
Which seal should I choose based on the ambient temperature?
| Implementation | Working limit |
|---|---|
| Uncooled oil seal housing (standard) | up to 110 °C |
| Standardised single balanced mechanical seal without cooling | up to 140 °C |
The specified temperature range for this series is 0–110 °C; therefore, operation above this limit must be agreed with Masdaf on a case-by-case basis. Please note that the temperature limits for OMKV seals differ from those of the KME and KMEV series: in those series, the standard seal is limited to 90 °C.
What materials are available for the flow-through section?
| Part | Standard | Options |
|---|---|---|
| Suction and discharge casings | GG25 cast iron | GGG40, AISI 304, AISI 316, CuSn10 bronze |
| Stage housing | GG25 cast iron | GGG40, AISI 304, AISI 316, CuSn10 bronze |
| Final-stage housing | GG25 cast iron | GGG40, AISI 304, AISI 316, CuSn10 bronze |
| Impeller | GG25 cast iron | GGG40, AISI 304, AISI 316, CuSn10 bronze |
| Gland | GGG40 high-strength cast iron | CuSn10 bronze |
| Shaft and shaft sleeve | AISI 420 | AISI 304, AISI 316 |
| Bearing housing and cover | GG25 cast iron | — |
The standard version is designed for use with pure water. For treated boiler water, demineralised water and other media that are corrosive to cast iron, the flow path is supplied in stainless steel.
How to position the pipes during installation
In the standard configuration, the discharge casing is located at the top, on the motor side, whilst the suction casing is at the bottom. The pump rotates clockwise when viewed from the drive side. The suction and discharge flanges are offset by 90°, allowing the pump to be integrated into the existing pipework without the need for adaptors. The manufacturer also offers versions with a different direction of rotation.
Where are OMKV pumps used?
- drinking water treatment plants and water distribution systems;
- increasing pressure in high-rise buildings and at industrial sites;
- water treatment and filtration plants;
- boiler feedwater and the condensate system;
- sanitary facilities and washing facilities;
- shipbuilding, the mining and energy sectors;
- irrigation;
- central heating systems.
How does OMKV differ from KMEV and KME?
All three series are Masdaf sectional multistage pumps with closed single-flow impellers and an operating pressure of 40 bar. They differ in their range and configuration. The OMKV is vertical and designed for high pressure at low flow rates: 5–180 m³/h at a head of up to 400 m, with flanges of DN 50–125. The KMEV is also vertical, but ‘wider and lower’: up to 300 m³/h with a head of up to 190 m. The KME is horizontal and the most powerful: up to 800 m³/h and 480 m, but requires more space for the unit. A practical guideline: if you need hundreds of metres of head with a modest flow rate and space is limited, go for the OMKV.
Selection, supply and service from Steiner Ukraine
At a head of 400 metres, the cost of an incorrect selection is higher than with a standard pump: excess stages result in throttling and wasted energy every day throughout the pump’s service life. To carry out the calculation, Steiner Ukraine requires: the nature and temperature of the fluid, the design flow rate and head, the suction pressure, material requirements and the room height. Based on this data, we determine the OMKV model with the required number of stages, agree on the materials, seal type and pipe orientation, and provide a specification. Spare parts — impellers, stage casings, shaft sleeves, wear rings, seals and bearings — are ordered using the pump designation on the nameplate.
