1 coupling repair Stainless steel pump coupling mainly rigid coupling and tooth-shaped coupling. (1) rigid coupling Rigid couplings are generally used in the centrifugal pump of smaller power, the first to remove the bolts and rubber elastic ring repair, the temperature is not high liquid, the two coupling plane clearance of 2. 2 ~ 4. 2 mm , The temperature is higher, should be greater than the former channeling amount 1. 55 ~ 2. 05 mm. Coupling rubber elastic ring than the perforation diameter should be small 0.15 ~ 0. 35 mm. At the same time disassembly must use special tools, keep smooth, do not allow scratches scratch. (2) tooth-shaped coupling Toothed coupling flexibility is better, with automatic centering performance. General maintenance by the following methods: ①Check the gear tooth meshing situation, the contact area along the tooth height not less than 50%, along the tooth width of not less than 70%, no severe pitting, wear and tear on the tooth surface; ② stainless steel pump coupling ring gear radial runout is not greater than 0.03 mm, the end of the round beating not more than 0.02 mm; ③ If you need to remove the ring gear, you must use special tools, not beat, so as not to bend or damage the shaft. When reassembly, the ring gear should be heated to about 200 ℃ before reloading to the shaft. Outer ring and shaft interference is generally 0. 01 ~ 0. 03 mm; ④ back to the middle of the barrel or other parts, should be the original mark and data assembly; ⑤ Tighten the bolts evenly with torque. 2 dynamic sealing part of the overhaul Centrifugal pump dynamic seal refers to the impeller mouth ring seal, the general radial direction should be controlled at 0. 20 ~ 0. 45 mm. If the clearance is too small, difficult to assemble the crank; gap is too large, easily lead to pump vibration. 2-0.6 mm. The radial direction of the sleeve and the lining ring gap is generally 0. 2 ~ 0. 6 mm. 3 static seal part of the overhaul Chemical pump static seal part includes the pump body split junction surface, bearing gland and bearing housing junction surface, the lube oil system joints, import and export of pipe flange, etc., such as overhaul can not guarantee no leakage, also make the pump can not run. The above parts of the seal, as long as the media selection of suitable adhesives and gaskets, which can guarantee no leakage. Are generally used in conjunction with the split surface adhesive South 703, South 704. 4 impeller and rotor overhaul Commonly used corrosion-resistant chemical pump for single stage impeller or single-stage double suction rotor. Inspection first check the appearance of the impeller and clean, whether it is the replacement of spare parts to install a new impeller, or cleaning the impeller, after the installation have to do static balance, if necessary, do dynamic balance. Impeller and shaft with the use of H / h, the impeller and keyway to install the correct contact. 04mm. Allowable bending of the shaft portion of the rotor portion is not greater than 0. 013mm, the maximum bending of the low speed shaft should be less than 0. 07mm, the maximum bending of the high speed shaft should be less than 0. 04mm. Assembly of shaft sleeve with H / h. For rotor shaft, overhaul rear axle radial runout is not greater than 0.013 mm, sleeve is not greater than 0.02 mm, impeller orifice ring is not greater than 0. 04 mm, impeller end runout is not greater than 0. 23 mm. Both ends of the shaft diameter of not more than 0.02 mm. However, for more complex centrifugal pumps, the above data may vary depending on pump conditions. 5 mechanical seal overhaul The chemical process pump seal inspection, should first use a special tool to remove the seal of the dynamic and static ring, and check the end face wear, any installed pump rotor, regardless of power size, should be done dynamic or static balance test . In order to ensure that the seal does not leak, the static and dynamic surface can be compacted on the fitter's platform, pouring water to leak test, if the static water does not leak, indicating that the sealing surface roughness and flatness are in line with the requirements. The vertical deviation of the end face during installation is not more than 0.015 mm. Part of the shaft or sleeve radial runout values ​​in Table 5. Speed ​​/ (r.min -1) Radial runout tolerance / mm Speed ​​/ (r.min-1) Radial runout tolerance / mm 750 ~ 1200 ≤0. 08 3500 ~ 7200 ≤0.03 1200 ~ 1500 ≤0. 06 7200 ~ 10000 ≤0. 02 1500 ~ 3500 ≤0. 05 45mm. After installation of the shaft axial movement of not more than 0. 45 mm. It should be emphasized that the mechanical seal installed on request, be sure to crank, and check the cooling water is reliable, to prevent leakage after rotation or damage the mechanical seal face. Mechanical pump used in chemical plants are mostly mechanical seal single-stage, two-stage, tandem sealed arrangement, but no matter what kind of seal arrangement can not leak. (1) pump single-stage seal arrangement Pump single-stage seal arrangement shown in Figure 3. Single-stage seal installation, you must ensure that the static and static parallel, bushings, journal parts should not have burrs and scratches. (2) Pump two-stage seal arrangement Pump two-stage seal arrangement shown in Figure 4. Double-stage arrangement of the seal installation must ensure that the positioning ring size and clearance, and once pushed to the position, O-ring can not escape the groove, or seal damage to seal machine. Speed ​​/ (r.min -1) Radial runout tolerance / mm Speed ​​/ (r.min-1) Radial runout tolerance / mm 750 ~ 1200 ≤0. 08 3500 ~ 7200 ≤0.03 1200 ~ 1500 ≤0. 06 7200 ~ 10000 ≤0. 02 1500 ~ 3500 ≤0. 05