That's a very common way to show true alignment (and to show off). I've been doing alignments 20+ years, both new (for Patterson until last year) and my own. Balancing and vibration analysis I started getting into a few years ago but decided against it only because there were so many really good firms locally for me to choose from, why bother. Any pump installed these days with a grid type coupling, or even the cheaper jaw type (all must be listed couplings) without an alignment report that also includes soft foot correction is crazy. Tolerances are so much tighter, and even closer as speed goes up, anything commissioned these past 10 years anyway, should be aligned and reported. Natural frequency would take hours to explain but it's a condition you can't always correct. We all vibrate. Sometimes it can be arrested but I see it often with tight piping and pipes passing through slabs and grouted. Flash backs are normal and healthy, I have them too. I remember Jerry and Duane on stage at Boston Common as I was peaking once playing Mountain Jam.... TD
Tom, This is diesel engine driven but I was thinking about your vibration analysis comment, 'soft foot', 'natural frequency'..., and I flashed back on an acceptance test of an electric motor driven I had designed and got to witness. Owner, Insurance, AHJ, Pump Rep- everyone is there. Churn hits steady state quickly, fitter looks at me, gets a nickel out of his pocket, says watch this, and has the audacity to stand the nickel up on top of the motor, centered both ways! It was a Friday so afterwards a very long lunch for everyone with lots of cold drinks was on me- and I just kept picturing that nickle standing there. Anyway, back in the present Friday I thought to myself, "I bet Tom has done that"! :) Brad Quoting [email protected]: > Well, nothing to share. > For some reason the valve was not acting up yesterday like it did in > the report. > Another reason why I think it has something to do with the discharge > pipe going underground and tieing in to storm drain. Who knows what > size that is, how many 90s, how far it is to the treatment plant or > wherever the outlet is, and the conditions there. Maybe there was some > gum in the works that day. > > Brad > > Quoting Brad Casterline <[email protected]>: > >> Thanks Matt and Tom. >> >> There will be an expert (i.e., not me) checking it out on site >> tomorrow and I will see about sharing the diagnosis here soon. >> >> >> >> Brad >> >> >> >> From: Sprinklerforum >> [mailto:[email protected]] >> On Behalf Of Tom Duross >> Sent: Tuesday, July 17, 2018 8:52 AM >> To: [email protected] >> Subject: RE: Excessive Vibration of Pressure Relief Valve >> >> >> >> Have a vibration analysis performed. That will indicate balance, >> soft foot, alignment, bearing, even natural frequency as the source. >> To bad we're so far away from each other. >> >> >> _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
