An off-line- to -running fixture combined with a shaft alignment system makes it possible to measure dynamic movements on machines from hot to cold or vice versa.
Dynamic changes in the rotating machinery from an Off Line toRunning condition, needs more attention. There is no such thingas 'identical' machines having identical dynamicmovements. One cannot ignore the possibility of horizontalmovement, assuming growth will be symmetrical and only accountingfor the thermal effects.
Shaft alignment has mostly been carriedout in off-line operating conditions.
However, machine conditionschange from the time they are off line to running under normaloperating conditions.
Some of these changes are due to processforces (fluid pressures, airflow, etc.).
The most notable ofthese changes is the change in the temperature of the machinebearings and supports.
Dynamic changes are difficult tocalculate.
Two 'identical' machines may showdrastically different alignment changes from Off Line to Running.Great care must be taken when calculating the changes in thealignment condition of machines.
Just because two machines appearidentical and serve the same function does not ensure they willexhibit the same operational characteristics.
Several methodshave been used to measure the changes in the shaft alignment oftwo or more machines.
Although widely used, 'hot aligningmachines', only measures changes in the shaft alignment duesolely to the changes in the machines' temperature.Discharge pressure, shaft torque, multiple machines operating inparallel, electrical loading of a generator, etc., can also playan important role in the change of the alignment condition fromOff Line to Running.
The changes will mostly be seen in theHorizontal Plane, but could also affect the Vertical Alignment.
Amachine that operates exposed to large changes in temperaturecould exhibit extreme changes in its shaft alignment as thetemperature changes.
Coupled machines need to be set to coldalignment targets that will reflect the actual changes in theshaft alignment.
This will lead to lower vibration levels,increased mean time between failures, decreased maintenancecosts, and increased production.
Fixturlaser's extensiveresearch into the problems of dynamic movement has resulted in arevolutionary new alignment method.
Fixturlaser L2R off-line- to-running fixture combined with a FixturlaserShaft alignmentsystem makes it possible to measure dynamic movements on machinesfrom hot to cold or vice versa.
Changes in machinery alignmentare mirrored by changes in the alignment of the L2R brackets.
Bymeasuring and documenting the initial position of the bracketsthe actual online changes in the alignment values can be measuredwhen the machine is online under normal operating conditions.Alignment costs are small compared to production loss, shouldcritical machinery fail.
Poor alignment is one of the leadingcontributors to premature rotating machinery failure, often as aresult of too little attention being paid to dynamic movements.Fixturlaser have, through extensive tests, showed that inaddition to cold alignments, the actual dynamic movements ofmachinery need to be considered when aligning.
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