NDD Series Between-Bearings Single/Two Stage Double Flow Axially Split Volute Casing Pumps

Applications: Designed for handling refined products at the process plants in the oil-refining industry.

May be also used to pump over industrial water through processing trains in the oil-refining industry as well as for handling water and condensate in the steam and water circuit systems.

Design: АNDD series pump units consist of a centrifugal pump and an induction motor in the explosion-proof version, which are mounted either on a common base plate (if the nominal power of the motor is less than 400 kW) or on separate base plates. The pump and motor shafts are connected by means of a flexible coupling. The pump units shall be rigidly anchored to the foundation, and piping shall be also rigidly connected to the pumps. The pumps as components of the pump units are electrically driven horizontal, between-bearings, single- or two-stage centrifugal pumps with double entry impellers.

The pump casings are:

  1. axially split, with a semi-spiral inlet hydraulic passage and a spiral outlet hydraulic passage (in case of NDD  140-140, NDD  420-100, NDD  420-200, NDD  800-30, NDD  800-60, NDD  1100-60 and NDD  1200-70);
  2. radially split, with a tangential semi-spiral inlet hydraulic passage and a circular outlet hydraulic passage (in case of NDD 600-320 U2, NDD 500-290 U2, NDD 800-230 U2 and NDD 850-180 U2).

Flanged nozzles are integrally cast with the pump casing and are oriented:

  1. horizontally (discharge) and vertically to the bottom (suction) in the NDD 140-140 model pumps;
  2. tangentially (the suction nozzle is on one side and discharge nozzles is on the other side of the shaft centerline), facing opposite directions, in the NDD 420-100, NDD 420-200, NDD 800-30, NDD 800-60, NDD 1100-60 и NDD  1200-70 pump models;
  3. radially at side (suction) and vertically to top (discharge) in the NDD 600-320 U2, NDD 500-290 U2, NDD 800-230 U2 and NDD 850-180 U2 pump makes.

Counter flanges have a weld neck.

The rotor axial thrust is hydraulically balanced. The residual axial forces arising as a result of an uneven wear of sealing surfaces in the running clearances are taken up by the bearings.

Casings of the pumps for hot refined products are supported in the horizontal plane near the shaft centerline to accommodate thermal expansions. In order to allow for free expansion of static components whilst maintaining coupling alignment, the pump feet on the drive side are rigidly dowelled to the base plate pedestal and the other end is pinned so that it should be axially moveable.

The rotor in the NDD 140-140, NDD 420-100, NDD 420-200, NDD 800-30, NDD 800-60, NDD  1100-60 and NDD 1200-70 pump models is carried by the oil-bath lubricated antifriction bearings with forced cooling.

The rotor in the NDD 600-320 U2, NDD 500-290 U2, NDD 800-230 U2 and NDD 850-180 U2 pump makes is carried by the pressure lubricated plain bearings, with lube oil supplied by a pressure lubrication installation.

Shaft sealing is by mechanical seals:

  • in tandem arrangement, which utilizes a pressurized barrier fluid, neutral to handled medium, and is provided with a cooling system in case of the pumps for hot refined products;
  • single seals provided with a liquid cooling system in case of the pumps for industrial water.

Upon the Customer’s request, pumps intended for handling industrial may be furnished with packed glands.

Handled medium near the shaft seals is cooled by cooling liquid supplied into the thermal barrier chambers.

Sense of rotation of pump shaft is shown with a rotation arrow attached to the pump casing or to the bearing housing on the drive side.

Г
DN
mm
100 - 350
200-350
Q
m3/h
1440
1020
H
m
238
325
p
kg/cm2
4
10
t
oС
+80
+400
n (sync)
rpm
1000, 1500
3000

Coverage chart of the NDD Series Pumps:

Performance of the NDD Series Pumps:

Pump make

Pump parameters

Capacity, m3/h Head, m Speed of rotation, rpm Power input (r=907 kg/m3), kW Efficiency, % NPSH required, m

NDD 140-140 U2

NDD 140-140-1 UKhL4

140

140

1500

77

69

2,8

NDD 420-100 U2

NDD 420-100-1 UKhL4

420

100

143

80

4,5

NDD 420-200 U2

NDD 420-200-1 UKhL4

200

286

79

NDD 800-30 U2

NDD 800-30-1 UKhL4

800

30

1000

83

79

4,0

NDD 800-60 U2

NDD 800-60-1 UKhL4

60

1500

166

79

NDD 1100-60 U2

NDD 1100-60-1 UKhL4

1100

60

1500

222

81

7,5

NDD 1200-70 U2

NDD 1200-70-1 UKhL4

1200

70

280

82

NDD 600-320-h U2

600

320

3000

805

65

6,0

NDD 500-290-h U2

500

290

620

64

NDD 800-230-h U2

800

230

655

77

NDD 850-180-h U2

850

180

560

75

 

Handled Media:

NDD XX-XX U2 - Refined products to 80 oС

NDD XX-XX-h U2 - Refined products to 400 oС

NDD XX-XX-1 UKhL4 - Water to 80 oС

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