Rotalign® Ultra LIVE TREND is by far the most cost-effective and technically competent tool to monitor pipe strain per API standards. LIVETREND allows maintenance personnel to monitor and record digitally the alignment offset changes at each coupling hub face,  thru the entire bolting procedure,  as specified, while comparing it to the final unit alignment if desired.” —Marty Krueger, Tern Technologies, Inc.

API 686 (Chapter 4, Piping Alignment) notes that the basic method of verifying pipe strain and its effect on the machinery is to monitor shaft alignment with dial indicators or lasers thru the machine flange torquing procedure. API 686 allows that an alignment change of +/- 0.002″ is acceptable while monitoring at the hub of the opposite machine (unless there is common piping between the two machines, then alignment changes should be noted at both hubs).

LIVE TREND allows the user to monitor the alignment change at both hubs, simultaneously and in real-time (at a user-specified data collection frequency) through the complete piping/flange torque procedure.  The system program also allows the user to “flag” and note each step of the procedure (suction line complete, discharge line complete, etc.).  LIVE TREND also allows the user to enter the final shaft alignment values (or actually take the final shaft alignment prior to start and import that data into the LIVE TREND program) so that the user not only can note the changes at the hubs as a result of the pipe/flange torque but also to note immediately if the change is within (or exceeds) the final alignment tolerances if the movement exceeds the +/- spec as per API.

It should also be noted that the LIVE TREND can be used to monitor the alignment thru the “Spring Hanger Function Checks” and any effects of possible piping strain to the machine during tear down, prior to overhaul, to give the user advance warning (and subsequent time to plan) for possible piping issues that might arise during reinstallation and re-attachment of piping.

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by Ana Maria Delgado, CRL