Multistage centrifugal pump is a common head high, the use of a wide range of industrial centrifugal pump, multistage centrifugal pump has many series, such as type D, type DG, type DF, type DM ( these are horizontal multi-stage centrifugal pump ); DL type, DLR type, GDL type ( these vertical multistage centrifugal pump ). Multistage centrifugal pump in use process when there will be some common problems, such as the balance disc wear, after starting not pump water, after starting water pump fixed, bearing heating, following the presentation of multistage centrifugal pump start without effluent reasons:
A multistage centrifugal pump, low speed
( 1) the human factor. Some users of the original motor damage, random with another motor drives, resulting in small flow rate, head low or no water supply consequences.
( 2) the mechanical failure of centrifugal pump. Impeller and pump shaft nut fastening loose or bent shaft deformation, resulting in multi-impeller transfer directly between the pump body, friction, or bearing damage, are likely to reduce the pump speed.
( 3) power machine repair. Due to burning of motor winding, and the magnetic loss, repair of winding turns, wire diameter, wiring methods change, or repair the fault does not completely rule out the factors which may change the pump speed.
Two, multistage centrifugal pump inlet and the pump body with air
( 1) the multistage centrifugal pump is not filled before the start of adequate water, and sometimes looks irrigation water from the discharge of Kong Yi, but not completely exhaust the air delivery pump shaft rotation, resulting in a little air left in the inlet or the pump body.
( 2) in contact with multistage centrifugal pump inlet pipe horizontal section against the flow direction of the application of more than 0.5% decline in slope, connecting the water inlet end to the top, do not complete the level. If the upward tilt, will be retained within the inlet air, reducing the pipes and pumps in the vacuum, the impact of water.
( 3) a multistage centrifugal pump packing because of long-term use of worn or packing pressed too loose, causing a lot of water from filling the gap with a pump shaft sleeve in smoke, the result is outside the air gap into the pump from the inside, affected the carrying water.
( 4) because of the long-term potential water inlet pipe, tube wall corrosion hole, multistage centrifugal pump to work after the water falling, when the exposed surface of these holes, the air from the hole in the pipe.
( 5) inlet pipe bend cracks, water inlet pipe and pump small gap junctions occur, are likely to enter the air inlet pipe.
Three, multistage centrifugal pump water inlet and outlet pipe in the resistance loss is too large
Some users after the measurement, although the reservoir or water tower to the source of the water surface is slightly smaller than the vertical distance between the lift pump, but still put a small amount of water or no water. Its reason is often the pipeline is too long, curved pipe, flow in the pipeline resistance loss is too large. Its reason is often the pipeline is too long, curved pipe, flow in the pipeline resistance loss is too large. In general 90 degree bend than 120 degrees bending resistance, each 90 degrees bend head loss of about 0.5-1 meters, 20 meters each pipeline resistance can make the head loss of about 11 meters. In addition, some users can pump into the pipe diameter, the head also has certain effect.
Four, multistage centrifugal pump Cheng Tai
Some deep water, some water at the periphery of relatively flat terrain, while ignoring the centrifugal pump allows the absorption process, resulting in little or no absorption of the absorbent not feeding results. To know the pump suction mouth can create vacuum degree is limited, absolute vacuum suction lift of about 10 meters high water column, and the centrifugal pump is not possible to establish an absolute vacuum. And vacuum through the large, easy to pump the water to the gasification, adverse working pumps. Therefore, the centrifugal pump has its absorption maximum allowable range, generally in the 38.5 meters. When the installation of pumps must not only easy.
Five other factors.
( 1) at the end of valve to open. Is usually set aside a long time due to centrifugal pump, valve gasket is stuck, no washer valve may rust.
( 2) valve can check valve malfunction or congestion will cause traffic to reduce smoking or even non-shui.
( 3) the export pipeline leak will also affect the mention of water.
( 4) filter network by the end of valve plug; or potential water valve at the end of the sludge layer caused by blocked filters.
( 5) the impeller inlet and duct clogging.