When using low pressure dry systems, one needs to change the train of thought when comparing to conventional dry pipe systems. The range between the nominal operating pressure, the low air pressure signal and the trip pressure are very tight, and you do not have the air pressure "cushion" that is normally provided with conventional dry pipe system air pressure ranges. Therefore, using a regulating type of air maintenance device and a tank-mounted air compressor or owner's air with low pressure dry systems is the best combination to prevent any mishaps. Using this configuration provides the system with a constant air pressure value, and the capability for safeguarding against minor air loss or rapid changes in air pressure, of which both accelerators and pressure actuators are sensitive to. Controlling-type air maintenance devices used in conjunction with bare (non-automatic) air compressors do not have this capability. Additionally, when manifolding air supplies for such systems, each system riser should hve its own regulating type of air maintenance device.
Regards, Salvatore Izzo, P.E. Manager - Reliable Technical Services ________________________________________ From: [EMAIL PROTECTED] [EMAIL PROTECTED] On Behalf Of Fox Duane T. (FireMarshal) [EMAIL PROTECTED] Sent: Wednesday, September 24, 2008 8:37 AM To: sprinklerforum@firesprinkler.org Subject: RE: Dry Valve Keeps Tripping Brian, You need to read the Victaulic fine print. We had the same problem in Delaware. You need an air maintenance device. It seems that they do not "require" the device but do recommend it. Apparently the diaphragm is very sensitive and will false trip with air surges. As I stated we had several issues with different installers, so we started checking into it, having the Victaulic rep do an informal class for the FMO. When we asked why the maintenance device is not required by the manufacture the rep stated competitive cost. All the problems we had were solved by installing an air compressor with a tank and an air maintenance device. Duane T. Fox, Jr. Asst Chief, Technical Services DE State Fire Marshal's Office -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brian Harris Sent: Wednesday, September 24, 2008 8:25 AM To: sprinklerforum@firesprinkler.org Subject: Dry Valve Keeps Tripping The valve originally was tripping within a couple of days, then it held for 3-4 months, then it began to trip again, sometimes within 2 hours after setup, the entire valve assembly was replaced, the system held for 3-4 days and now has tripped again. FYI, Victaulic NXT Dry Pipe Valve pre-piped version is being used. Also, the system was introduced with debris due to false underground papers provided, however the system was flushed thoroughly, can there be any residual problems from this? Can the air compressor have any impacts, even though the dry valve is one of those low air pressure valves? This installation is at a Hospice and the Fire Marshal will not let the strobes be turned off until the system is put back into service. the owner is hot, to say the least! Regards, <http://www.firstdefensefire.com/> E-mail message checked by Spyware Doctor (6.0.0.383) Database version: 5.10770 http://www.pctools.com/en/spyware-doctor-antivirus/ _______________________________________________ Sprinklerforum mailing list http://lists.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 http://lists.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)
