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Pump type
SE 1250-70-11

Model: SE 1250-70-11
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Pump type
SE 1250-70-11

The SE 1250-70-11 pump and the unit based on it are designed for pumping water in heating networks. The water must not contain solid particles larger than 0.2 mm or with a concentration exceeding 5 mg/l.

The pumps are manufactured in the UHL climate version — intended for macroclimatic regions with moderate and cold climates, placement category 4 — operation in rooms (volumes) with artificially controlled climatic conditions according to GOST 15150-69.

Pump designation FLOW RATE, m3/h Pressure, m ROTATION SPEED, rpm ALLOWABLE NET POSITIVE SUCTION HEAD, m Pump efficiency, % Motor power, kW Pump weight, kg Unit weight, kg
SE 1250-70-11 1250 70 1500 7,5 83 315 1400 4000

APPLICABILITY OF THE SE 1250-70-11 NETWORK PUMP

The network pump belongs to a special group of power pumps, whose operation is characterized by fluctuations in the temperature of the supplied water across a wide range of flow rates, and is designed for pumping water at temperatures up to 180 °C in heating networks.

TECHNICAL SPECIFICATIONS

Nominal pump parameters

  • Flow rate, m³/h: 1250
  • Head, m: 70
  • Allowable cavitation margin, m*: 7.5
  • Efficiency, %: 83
  • Temperature, °C: 10–180
  • Rotation speed, rpm: 1500

*This is an important parameter to consider when designing the external network (piping and valves) and selecting pump equipment.

DIMENSIONS AND WEIGHT

  • Weight, kg
    • pump: 1400
    • unit: 3600
  • Dimensions (widthlengthheight), mm
    • pump: 116016101160
    • unit: 116034201660

The SE 1250-70-11 network pump is driven by an asynchronous squirrel-cage rotor electric motor with a power of 315 kW. The overall efficiency of the system (η) is 79 %.

MAIN REQUIREMENTS FOR THE DESIGN OF THE SE 1250-70-11 NETWORK PUMP:

  • High reliability and cost-effectiveness
  • External tightness and absence of internal leakage at rotor and stator joints
  • Long service life — average time to major overhaul not less than 35,500 hours (with full maintenance compliance)
  • Dynamic stability across the entire operating range
  • Stable, continuously decreasing head curve to ensure stable operation in parallel operation
  • Ease of assembly, disassembly, maintenance, and high maintainability under operating conditions

CONSTRUCTION FEATURES OF THE SE 1250-70-11 NETWORK PUMP:

  • Horizontal design, providing high vibration resistance, reducing shaft misalignment, and increasing the service life of components
  • Spiral type with a horizontal split along the pump axis, ensuring high maintainability, easy technical service, installation, and simple operation
  • Inlet and discharge nozzles at the bottom of the casing for assembly and disassembly without disconnecting pipelines
  • Single-stage with a double-suction impeller
  • Pump casing is a complex cast iron casting in two parts (pump cover and pump body) with semi-spiral suction and spiral discharge channels, inlet and outlet nozzles, bearing supports, and trough-shaped brackets for leak collection. Bearing supports are positioned close to the pump axis to reduce misalignment during heating. Two pins fix the casing to the foundation frame to allow controlled thermal expansion
  • Rotor is a separate assembly consisting of the shaft, double-suction impeller, bushing, spacer bushing, stuffing-box bushings, bearings, and half-coupling. Axial movement of the impeller is fixed via stuffing-box bushings with nuts. Thermal gaps are provided to compensate for thermal expansion
  • Rotor is axially unloaded via the double-suction impeller
  • Rotor supported by external rolling bearings: drive side (cylindrical roller bearing) handles radial loads; opposite side (double-row angular contact ball bearing) handles radial and residual axial loads. Bearings are lubricated with liquid, ring (crankcase) lubrication, with cooling chambers and coils for water cooling
  • Stuffing-box type mechanical seals with a sealing ring. Cooling passages are provided for seal fluid circulation under pressure, preventing air ingress
  • Torque transmitted from motor to pump via flexible sleeve-pin coupling

MATERIAL SPECIFICATIONS OF THE SE 1250-70-11 NETWORK PUMP (CHT Slovakia s.r.o.):

  • Pump casing, impeller, sealing rings, bearing housings made from SCh200 cast iron — high strength and corrosion resistance
  • Pump shaft made from heat-treated 40X steel — high strength and wear resistance
  • Stuffing-box bushings made from stainless steel 20X13 — efficiency and durability

ADDITIONAL SUPPLY OPTIONS:

  • Mechanical seal — reduces volumetric leakage, improves energy efficiency, easy to maintain
  • Higher-class materials and coatings for flow parts to increase erosion resistance
  • SKF rolling bearings — high precision, low friction, high-speed operation, low noise, wear, heat generation, and energy consumption
  • Flexible disc coupling between motor and pump — improved vibration characteristics and reliability
  • VDS monitoring system — includes vibration, speed, and temperature sensors for real-time monitoring, analysis, and maintenance planning

PURCHASE SE 1250-70-11 NETWORK PUMP FROM CHT Slovakia s.r.o.

To order a specific unit or get consultation on selection, contact our sales department via phone or submit a request through the feedback form. Delivery is available to all CIS countries (except Russia and Belarus) and European countries.