----------------------------------------------------------------------------------------------------------------------------------------------
* Description-High Pressure Centrifugal Boiler Feed Water Pump

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 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 105oC, and is also
applicable for small boiler water supply or transporting medium similar to hot water.
Performance range of model QD (G) series
Flow : 3.75-185 m3/h
Corollary power: 4.0-400kW
Head: 69-684m
Inlet diameter: 40-150mm
 
QD (G) model hypo-high-pressure boiler water supply pump is applicable to transport medium with temperature of not higher than 160oC, and is also applicable for small boiler water supply or transporting medium similar to hot water. 
 
Performance range of mode QD (G) series
Flow: 1 5-3 00m3/h
Corollary power: 75-1 250kW
Head: 390-1050m
Inlet diameter: 65-200mm

--------------------------------------------------------------------------------------------------------------------------------------- 
 * Application-High Pressure Centrifugal Boiler Feed Water Pump

 1)Municipal engineering ,Wastewater treatment ,constructional engineering 
 2)Agricultural irrigation , transfer water ,etc.
 3)High-rise buildings water supply and drainage, and for fire working
 4)Factory and mining for distance water supply and drainage
 5)Circulation water supply for production process
 6)Cooling systems of air-conditioning in hotels
 7)Domestic water supply

----------------------------------------------------------------------------------------------------------------------------------------------
*Sturcture-High Pressure Centrifugal Boiler Feed Water Pump

Pump is supported by both ends, and casing portion is sectional. It connected with motor by flexible coupling. Viewing from the motor end, pump is in clockwise direction rotating. Refer to Fig. I for the structure of it.
 
1) Stator portion
Have suck-in section. middle-section, discharge section, guide vane, stuffing box etc., which connected by bolts
 
2)Rotor portion
Main parts includes shaft, impeller, balancing disk, shaft sleeve etc.
 
3)Bearing portion
Roller bearings or sliding bearings on both ends support whole rotor, bearings are lubricated with grease or 20# engine oil.
 
4)Cooling and seal of pump
Seals joint surface of suck-in, middle, and spitting section by molybdenum disulfide lubricating grease. Seals rotor and stator by ring, diffusor sleeve and packing. The packing should be proper and leak drop by drop. Forbid unload running. Change seal ring and diffusor sleeve if they damaged and influence pump. The changeable shaft sleeve near shaft seal can protect
pump shaft. Must have seal water if run. If medium temperature is above 80oC, fill cooling water to gland assembly and shaft seal cooling chamber. Cooled water and seal water should be clean water in normal degree. Cooled water pressure should be l.5~3Kg/cm2, seal water should be more than 0.5~1 Kg/cm2 of the seal chamber. The positions of cooling water pipe joints are different for various kind of water pumps. Please refer to construction drawing of pump for axial position, and refer to chart I for radial position.Shaft seals are classified as packing seal and mechanical seal. Seal water of packing seal is industrial water, with pressure of 2~3kg/cm2. The flushing water of mechanical seal is softened water, pressure must
higher 3kg/cm2 than inlet pressure.