This is poorly worded for one thing. Typically the mandate of reduction of flow to fire sprinkler systems when the municipal supply pressure falls to or below 20 psi is a requirement of the local water purveyor. This doesn't always result in the water supply being completely shut off, it can be throttled back so that the source pressure is maintained to the minimum set point. However this does have an effect on sprinkler discharge and hose discharge.
To accomplish this you install a low suction control valve in the main system supply. If you have a high value or high risk installation and the local water purveyor has this requirement, it's a good idea to let the owner know this puts their property at risk and to consider an on-site water storage tank and pump, especially if the local water supply is weak to marginal. Craig L. Prahl, CET Fire Protection CH2MHILL Lockwood Greene 1500 International Drive Spartanburg, SC 29304-0491 Direct - 864.599.4102 Fax - 864.599.8439 CH2MHILL Extension 74102 [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Timothy W Goins Sent: Monday, November 12, 2012 12:20 PM To: [email protected] Subject: 20 PSI Minimum How are others addressing the 20 PSI minimum operating pressures of the fire sprinkler system? Here is a quote from a spec that I have received. "The fire protection systems shall not be designed to operate if the residual pressure of the existing water service falls to 20 psi or lower at design flow requirements." Timothy W Goins A & T Services "For I am not ashamed of the gospel of Christ: for it is the power of God unto salvation to everyone that believeth;." KJV Romans 1:16 Reply to <mailto:[email protected]> mailto:[email protected] -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://fireball.firesprinkler.org/mailman/private/sprinklerforum/attachments/20121112/9c2eef0f/attachment.html> _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
