General


Model QD (G) pump is a horizontal multi-stage centrifugal pump and suitable for transporting pure water (with the contained foreign matters' content less than l % and graininess less than 0. 1mm) and other liquids of both physical and chemical natures similar to those of pure water.
QD (G) model middle and low pressure boiler water supply pump is applicable to transport medium with temperature of not higher than 120℃, and is also applicable for small boiler water supply or transporting medium similar to hotwater.
QDG model hypo-high-pressure boiler water supply pump is applicable to transport medium with temperature of not higher than 180℃, and is also applicable for small boiler water supply or transporting medium similar to hot water.
Performance range of mode QD (G) series
Flow: 3-500m3/h Corollary power: 75-3400kW
Head: 390-684m Inlet diameter: 25-450mm


Structure


For this series horizontal multistage centrifugal pump, both ends of it are supported, the casing portion is in a sectional form. it is connected to and actuated by a motor via a resilient clutch and the rotating direction of it. viewing from the actuating end. is clockwise. Refer to Fig. I for the structure of it.


Stator portion
Consists of suck-in section. middle-section, spitting section, guide vane, packing etc., which are linked together with a take-up bolt. with both suck-in and spitting mouths vertically upward.


Rotor portion
Consists of a shaft, impeller, balancing disk, muff etc. Parts.


Bearing portion
The whole rotor is supported by the roller bearings or
sliding bearings on both ends of the shaft and the bearings are lubricated with grease or 20# engin oil.


Cooling and seal of pump
The joint-part between suction section, intermediate
section and discharge section with be coated with molybdenum disulfide lubricating grease as seal. Rotor and fixed parts will be sealed by seal ring, guide-vane jacket and packing. The packing tensile degree of shaft seal should be proper and seep should be feasible dip by dip Unload run should be forbid. The seal ring and guide vane jacket should be replaced if they are too worn to be used any more and even do harm to pump work. There is spare shaft sleeve near shaft seal to protect shaft of pump.






Performance


QD(G) Series multistage pump data
Pump Type Flow Head Power
(m3/h) (m) (KW)
QM(G) 6-25 3-7.5 73.5-306 4-11
QM(G) 12-25 7.5-15 69-338.4 5.5-22
QM(G) 12-50 7.5-15 139.5-648 18.5-75
QM(G) 25-30 15-30 82.5-340 15-45
QM(G) 25-50 15-30 15.78-618 22-110
QM(G) 46-30 30-55 81-340 22-75
QM(G) 46-50 30-55 138-666 37-132
QM(G) 85-45 55-100 78-459 37-160
QM(G) 85-67 55-100 183-666 90-250
QM(G) 155-67 100-185 177-684 132-400
QM(G) 280-43 185-335 114-423 160-450
QM(G)280-65 185-355 372-680 500-800
QM(G)450-60 335-684 171-650 360-3400