Multi-stage pump assembly preparations before

Centrifugal pump in the assembly, must be ready. Preparations include the following: 1, assembly personnel must be familiar with the structure of the pump to understand the assembly sequence and assembly methods; 2, ready to assemble the tools needed, measuring tools; 3, the various parts to be cleaned, worn parts repaired as required Good; 4, pre-assembled parts of the inspection. For multi-stage pumps, the rotor section (including the impeller, impeller block or impeller hub and balance disc, etc.) should be pre-assembled, also known as small rotor or trial installed to check the rotor concentricity ≤ 0.05mm), skewness and the distance between the impeller exit. The impeller, impeller sleeve and balance disc mounted on the calibrated pump shaft, the sleeve lock, the installation at the lathe tip or supported on the V-shaped iron (or bearing). 1) Check the rotor concentricity as follows: (1) Divide the circumference of the rotor into eight equal parts (the impeller can also be divided by the number of blades), and make the mark. Place the dial indicator on the outer circle of the impeller and the outer circumference of the impeller, the outer circumference of the impeller, the outer circumference of the sleeve, and the outer circumference of the balance disc. Slowly move the rotor, each turn an aliquot, record a dial indicator readings. After one revolution of the rotor, the dial indicator at each measuring point will be given eight readings and the readings will be recorded. (2) The maximum reading at each measuring point minus the minimum reading is the eccentricity of the rotor. The purpose of measuring rotor eccentricity is to check the concentricity of the various components and the pump shaft. If the eccentricity exceeds the allowable value, lathe turning available to meet the requirements. 2) Rotor skew check method Rotor skewness mainly checks the impeller mouth end surface and the balancing disc and balance ring friction surface. After the pump shaft is level, the friction face of the impeller mouth face and the balance disc should be a vertical plane perpendicular to the axis of the pump. If the vertical plane deflection, the operation will be serious wear and tear, or even affect the work of balance plate. When checking skewness, use a dial indicator horizontal to the side of the impeller, balance pan. Turn the impeller and balance plate, the maximum reading of the dial indicator minus the minimum reading, is the skewness. Tilting exceeds the provisions of the turning correction can be used. 3) Measurement and Adjustment of Spacing (1) Contents: a, the distance between the adjacent impeller exit; b, the total spacing of the first stage impeller and the last stage impeller; c, the inlet spacing of adjacent guide vanes; d, The total distance of imports. (2) Measurement methods and adjustments: Impeller spacing to the center of the impeller or the edge of the impeller as a benchmark, with a steel ruler or special caliper to measure. The error of each pitch or total pitch should not exceed 1 millimeter or less in general. If not meet the requirements, should be adjusted. Adjustment method, according to the specific circumstances. For example, the total spacing to meet the requirements, but there are individual spacing requirements, and some spacing, some spacing is small, mostly due to the uneven length of the impeller hub. At this point the order of the original assembly impeller or sleeve change more appropriate, learn from each other, you can adjust well. If this is not possible or if the total spacing is not satisfactory, then replace several impellers or bushings, file longer impeller hubs, and add copper gaskets between the impeller and stopcock to meet the requirements. The midsection and guide vane spacing is based on the guide vane and midsection sides and is measured using a steel rule. When the spacing is not suitable, use the method of changing the thickness of the gasket to adjust. In short, to make the distance between adjacent impellers equal and equal to the distance between adjacent guide vanes, the total distance between the first and last impeller exit is equal to the total distance between first and last guide vanes with shims spacing. After adjusting the impeller or the middle section, it should be marked, indicating the order, so as not to make mistakes during assembly. 5, according to the combination of parts, as far as possible the first part of the assembly of small parts (1) First, the seal ring and impeller should be assembled so that the gap with the standard, and the seal ring assembly to the corresponding middle and suction section. (2) If there are guide vanes, also have to be mounted on the guide vane. (3) If it is a removable guide vane, also have to be assembled to the middle section. (4) The sliding bearing parts were assembled, composed of two bearing frame. (5) matching a good balance sleeve, balance the balance wheel and the balance of the wheel 符 meet the requirements. (6) Assemble the gimbal to the discharge section. 6, after the trial assembly of the rotor assembly should be completed dynamic balancing test. 7, to check the good parts or assembled parts according to the order of assembly for assembly.