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] <mailto:[EMAIL PROTECTED]> e-mail
www.ParsleyConsulting.com <http://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)
