Page 234 - Water Standards
P. 234

requirements:
                 1) The bearing liner shall meet the following requirements:
                      Table 4   2   3-6  Allowable error of elevation and
                               gap of runner installation    Unit: mm

             No          Item           Allowable error   Explanation

                                                        The uneven misalign⁃
                         Mixed⁃flow type   ±1   5     ment between the fixed
                                                      and rotating sealing rings

                                                        The distance from the
             1   Elevation
                          Axial⁃flow type  0-+2   0   bottom ring to runner
                                                      top surface

                                                        The gap between the
                          Diagonal flow
                                          0-+0   8    vane and  the  runner
                             type
                                                      chamber
                                         The difference be⁃
                                                        The gap between the
                                      tween each gap and
                                                      vane and runner chamber
                          Working head  actual  average  gap
                                                      at the inlet, outlet and
                            <200m     shall be no larger than
                                                      the middle when the run⁃
                                      ±  20%  of  the
                                                      ner is totally closed
                                      average gap
                                         The difference be⁃
                                      tween each gap and
                                  a 1  actual  average  gap
             2     Gap
                                      shall be no larger than
                                  a 2
                                      ±  10%  of  the
                                      design gap
                         Working head
                          ≥200m
                                         The difference be⁃
                                      tween each gap and
                                      the actual average gap
                                   b 1
                                      shall be no larger than
                                   b 2
                                      ± 10% of the design
                                      average gap
                    —The rubber bearing liner surface shall be smooth and have no flaws such as fis⁃
                                                                 2 2 7
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