PDF Archive

Easily share your PDF documents with your contacts, on the Web and Social Networks.

Share a file Manage my documents Convert Recover PDF Search Help Contact



NMZ Type Horizontal Split Case Centrifugal Pump .pdf



Original filename: NMZ Type Horizontal Split Case Centrifugal Pump.pdf
Author: bt-3

This PDF 1.7 document has been generated by WPS Office / , and has been sent on pdf-archive.com on 26/10/2017 at 12:10, from IP address 122.234.x.x. The current document download page has been viewed 188 times.
File size: 156 KB (6 pages).
Privacy: public file




Download original PDF file









Document preview


Croos Pump (Shanghai) Co., Ltd
http://www.croospump.com/

NMZ Type Horizontal Split Case Centrifugal Pump

Description of Horizontal Split Case Pump:
NMZ series are horizontal, single stage, axially split case, double suction, between bearing,
centrifugal pumps. It’s suitable for pumping clean water or slightly contaminated water or liquids
which is physically and chemically similar to water, where large quantity and certain head are
required. The axially split casing design makes it’s easy to remove the upper volute casing and
rotary components without disturbing the motor and the pipework. And the double suction
impeller ensures high efficiency.

Horizontal Centrifugal Pump Design Features:

Axially pump casing

The casing is axially split, the inline suction and the discharge nozzles are in the lower half
casing, this design makes it’s easy to remove the upper casing and rotary components without
disturbing the motor and the pipework.



Dual Volute Casing

Tel: +86-21-64092786

Email: export@croospump.com

Croos Pump (Shanghai) Co., Ltd
http://www.croospump.com/
Pumps generating high heads have dual volutes to reduce radial forces, ensuring minimal shaft
deflection and low bearing loads.



Between bearing design

Less shaft deflection due to the between-bearing design.



Wear Rings

Easily replaceable casing wear rings, protect the pump casing from the abrasion of the impeller.
The overall cost of operation is minimized.



Sealing Flexibility

Pump can be sealed by gland packing or wide range of mechanical seals

Horizontal Split Case Pump Operation Data:
50Hz

60Hz

40 to 500mm

Discharge Diameter

1.6 to 32 in

50 to 11,600m³/h

Capacities

220 to 51,073 USgpm

Up to 260m

Heads

Up to 656 ft

Up to 2.5MPa

Pressures

Up to 362.6 psi

Up to 120° C

Temperatures

Up to 248 ° F

Horizontal Split Case Centrifugal Pump Material Available:
Material Combination
Pump Part
Cast Iron

Ductile Iron

Carbon Steel

Tel: +86-21-64092786

SS 304

SS 31
6L

Duplex

Email: export@croospump.com

Super Duplex

Bronze

Croos Pump (Shanghai) Co., Ltd
http://www.croospump.com/

Casing

Cast Iron

Ductile Iron

Carbon Steel

SS304

SS316

Duplex

Super Duplex

Bronze

impeller

Cast Iron

Ductile Iron

Carbon Steel

SS304

SS316

Duplex

Super Duplex

Bronze

Shaft

SS 420

SS304

Duplex

Seal housing

Cast Iron

SS304

SS316

Duplex

Super Duplex

SS316

Duplex

Super Duplex

Stationary Ring

Ductile Iron

Carbon Steel

Carbon Steel

SS304

Super Duplex

Horizontal Axial Split Casing Pump Application:
Water transport
Water supply and distribution
Irrigation, drainage and flood control
District cooling/heating
Fire fighting

Tel: +86-21-64092786

Email: export@croospump.com

Bronze

Croos Pump (Shanghai) Co., Ltd
http://www.croospump.com/
Analysis of Various Misunderstandings in the Use of Centrifugal Pumps
1. Low lift operation of high lift water pump
Many people think that the lower the lift, the lower the motor load. In the misleading of this false
knowledge, when the water pump is selected, the pump's lift is often high. In fact, for centrifugal
pumps, when the pump model is determined, the power consumption is proportional to the
actual flow of the pump. The flow of the pump decreases with the increase of the lift, the higher
the lift, the smaller the flow and the less power consumed. Conversely, the lower the head, the
larger the flow, the greater the power consumption.
Therefore, in order to prevent the motor overload, it is generally required that the actual
pumping use of the pump shall not be less than 60% of the nominal lift. When the high lift is used
to pump water too low, the motor is overloaded and hot, which can burn the motor. Emergency
use must adjust the water flow gate valve on the outlet pipe to reduce the flow and prevent
motor overload.
Pay attention to the temperature rise of the motor. If the motor is too hot, we should turn off the
small outlet flow or shutdown. This can also be misleading, with some players thinking that
blocking the outlet and forcing down the flow will increase the load on the motor. In fact, the
opposite is true. The normal high power centrifugal pump discharge line is equipped with gate
valves. In order to reduce the motor load at the start of the unit, the gate valve should be closed
first and the gate valve will be opened gradually after the motor starts.
2. Large diameter water pump with small pipe pumping
Many users think this can improve the actual lift, actually the actual lift of the pump = total head
lift - loss of lift. When the pump model is determined, the head lift is certain; The loss of the lift
mainly comes from pipeline resistance. The smaller the diameter of the pipe, the greater the
resistance is. Therefore, after reducing the pipe diameter, the actual lift of the pump will not
increase but decrease, resulting in the decrease of water pump efficiency.
In the same way, when the small diameter water pump is pumped, it will not lower the actual lift
of the pump, but it will reduce the loss due to the decrease in the resistance of the pipe, which
will improve the actual lift. There are also users who believe that small pipe diameter pumps will
greatly increase the load of the motor when pumping water. They think that when the diameter
of the pipe increases, the water in the pipe will be more pressure on the pump impeller, which will
greatly increase the load of the motor.
It is not known that the size of the liquid pressure is related to the height and height of the head,
but not the size of the area. As long as the lift is certain, the impeller size of the pump is the same,
regardless of the size of the tube, the pressure on the impeller is certain. As the diameter
increases, the flow resistance decreases, and the flow rate increases, and the power consumption
increases appropriately. However, as long as the water pump is increased in the range of the
Tel: +86-21-64092786

Email: export@croospump.com

Croos Pump (Shanghai) Co., Ltd
http://www.croospump.com/
rated lift, it is possible to work normally, and it can reduce pipe loss and improve water pump
efficiency.
3. The pipe section of the inlet pipe is too flat or upturned
This will bring the air into the water pipe and reduce the vacuum of the water pipe and water
pump, so that the water will be lowered and the amount of water will be reduced. The correct
approach is that the horizontal section should be slightly inclined to the direction of the water,
and it should not level, not even upward tilt.
4. The inlet pipe bends too much
If you use more elbow on the inlet, you will increase the resistance of local water flow. And the
elbow should turn in the vertical direction, not allowing the turn in the horizontal direction to
avoid the accumulation of air.
5. The water pump inlet and bend are directly connected
This makes the water flow unevenly through the elbow and into the impeller. Eccentric reducer
should be installed when the inlet pipe is larger than the pump inlet. The eccentric tapered
section shall be mounted on top, and the inclined plane shall be mounted below. Otherwise, the
air will gather, and the water output is reduced, or the water can not be pumped, and there is a
crash sound. If the inlet pipe is equal to the diameter of the water pump inlet, the pipe should be
kept between the inlet and the bend of the pump. The length of the straight pipe shall not be less
than 2 ~ 3 times the diameter of the pipe.
6. The bottom end of the inlet pipe is not perpendicular
In this way, the valve cannot shut itself down and will cause a leak. The proper installation method
is that the inlet pipe with bottom valve preferably vertical in the next section. If because of the
terrain conditions, it cannot be installed vertically, the pipe axis and horizontal plane angle should
be in more than 60 °.
7. The inlet position of the inlet pipe is not correct
The inlet of the inlet pipe is less than the inlet diameter of the inlet and the wall of the water
inlet. If there is dirt and dirt at the bottom of the pool, the water inlet is less than 1.5 times the
distance from the bottom of the pool, it will cause the water to be blocked or absorbed into the
water to fill the inlet.
When the inlet of the inlet pipe is not enough depth, it will cause a vortex of water around the
inlet, and it will affect the water and reduce the amount of water. The correct installation method
is that the water depth of the small and medium water pump shall not be less than 300 ~ 600 mm,
and the large pump shall not be less than 600 ~ 1000 mm.

Tel: +86-21-64092786

Email: export@croospump.com

Croos Pump (Shanghai) Co., Ltd
http://www.croospump.com/
8. The outlet is above normal water level
If the outlet is above the normal water level of the tank, although it increases the lift of the pump,
it reduces the flow rate. If the water level of the outlet must be higher than the water level due to
the topography condition, the pipe should be installed with elbow and short pipe, so that the
pipe will become siphon and reduce the outlet height.

Tel: +86-21-64092786

Email: export@croospump.com


Related documents


axial split casing centrifugal pump
nmz type horizontal split case centrifugal pump
cot type horizontal easy
llk type close coupled centrifugal pump
ge type horizontal end suction centrifugal pump
ast type horizontal double support centrifugal pum


Related keywords