THATS IT THANKS KEN, Dennis Briggs, Jr. Miller Fire Protection Inc. 2750 Marble Ct. Forestville MD. 20747 Office - (301) 736-3000 Cell - (240) 304-8967 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Friday, May 23, 2008 01:32 PM To: [email protected] Subject: Re: Pressure Switch on Pumps
Dennis, How about this, from Annex A.14.2.7 in the '03 edition of NFPA-20: Fire Pump Settings. The fire pump system, when started by pressure drop, should be arranged as follows: (a) The jockey pump stop point should equal the pump churn pressure plus the minimum static supply pressure. (b) The jockey pump start point should be at least 0.68 bar (10 psi) less than the jockey pump stop point. (c) The fire pump start point should be 0.34 bar (5 psi) less than the jockey pump start point. Use 0.68 bar (10 psi) increments for each additional pump. (d)Where minimum run times are provided, the pump will continue to operate after attaining these pressures. The final pressures should not exceed the pressure rating of the system. (e)Where the operating differential of pressure switches does not permit these settings, the settings should be as close as equipment will permit. The settings should be established by pressures observed on test gauges. (f) Examples of fire pump settings follow (for SI units, 1 psi = 0.0689 bar): i. Pump: 1000 gpm, 100 psi pump with churn pressure of 115 psi ii. Suction supply: 50 psi from city — minimum static; 60 psi from city — maximum static iii. Jockey pump stop = 115 psi + 50 psi = 165 psi iv. Jockey pump start = 165 psi - 10 psi = 155 psi v. Fire pump stop = 115 psi + 50 psi = 165 psi vi. Fire pump start = 155 psi - 5 psi = 150 psi vii. Fire pump maximum churn = 115 psi + 60 psi = 175 psi *Is that what you were after?* PARSLEY CONSULTING Ken Wagoner, SET 760.745.6181 voice 760.745.0537 fax [EMAIL PROTECTED] e-mail www.ParsleyConsulting.com website Dennis J Briggs Jr. wrote: > Im having trouble finding the information that relates to setting the pressure switch on fire pumps. > does anyone know where i may find this i recall reading about it somewhere. I thought it would be in NFPA 20 but i cannot seem to locate it. > > Thanks, > Dennis Briggs, Jr. > Miller Fire Protection Inc. > 2750 Marble Ct. > Forestville MD. 20747 > Office - (301) 736-3000 > Cell - (240) 304-8967 > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > To Unsubscribe, send an email to:[EMAIL PROTECTED] > (Put the word unsubscribe in the subject field) > > > _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
