The pumps are listed by UL per an approved, ISO registered process. The mfr wont guarantee a new pump to perform up to and including the safety margin.
You are proposing a performance based design, using the safety margin. If this is not an accepted design method in new pump installations, then it is likely not in retro fits either. The pump performance test could be used to measure any degradation in performance against the original curve. Forest Wilson Cherokee Fire Sent from my Verizon Wireless Phone ----- Reply message ----- From: "Fletcher, Ron" <[email protected]> Date: Wed, Sep 1, 2010 9:58 am Subject: Diesel Pump Engine RPM To: <[email protected]> For a retrofit you wouldn't do a pump test and then use the results of the test for the calculations? Ron Fletcher Aero Automatic Phoenix, AZ -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, August 31, 2010 6:50 PM To: [email protected] Subject: Re: Diesel Pump Engine RPM I would contact the mfr. The listing is based on their data sheets i believe. So the calcs are based on the listed, approved pump. Forest Sent from my Verizon Wireless Phone Sent from my Verizon Wireless Phone ----- Reply message ----- From: "Tom Duross" <[email protected]> Date: Tue, Aug 31, 2010 8:09 pm Subject: Diesel Pump Engine RPM To: <[email protected]> Short answer, yes I believe. Typically, engine speed required by the pump is at 150% and climbs according to the engine as you approach no load. Engines have an operating range and usually selected and governor set for the pump's requirements. I thought there might be a disclaimer in the most recent 20 regarding PLD controllers, but not to my knowledge. I know with non-PLD controllers, we always start at 150% and work our way back when testing engine-driven pumps as that helps cool-down. Plus, you can check RPM at first flow point. It's unfortunate affinity calculations are based upon constant speed (as I understand them), which never exists regardless of driver type. Sorry for seeming vague but the books beyond arms reach. TD NFPA #20, 2003, 11.2.4.1.1. "Engines shall be provided with a governor capable of regulating engine speed within a range of 10 percent between shutoff and maximum load condition of the pump." Does this mean that a 1760 rpm rated engine running at 1860 rpm is acceptable? If a 1760 rpm rated pump when tested produced 1860 rpm (less than 10%) can the pressure produced at the higher rpm be used for the system calculations? In other words can the actual pump test be used for the system calc's or must we use the manufacturers data sheet regardless the test results? The pump is a PLD if that matters. Ron Fletcher _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
