Douglas, The problem appears to be when the two small orifices in the ¾” port are plugged and water doesn’t flow through the trim to the pressure switch. Check carefully in systems more than five years old and where corrosion in the dry pipe system is more evident. You will need to remove the ¾’ trim in the back, clean the two orifices, flush water through the intermediate chamber (after cleaning the seat) and then flush through the two orifices.
Fitters that are doing this please help us out with any more details. A small drill bit turning it with your fingers only, so you don’t pack it in; something that won’t / can’t damage the casting… This would be in full trip tests, partial trip tests, and the valve operating as intended in a trip condition. You do not have this problem when you use the alarm test bypass, but doing the alarm bypass test doesn’t test the functionality of the valve. Scott Office: (763) 425-1001 x 2 Cell: (612) 759-5556 From: Sprinklerforum [mailto:[email protected]] On Behalf Of Douglas Hicks Sent: Saturday, April 15, 2017 10:34 PM To: [email protected] Subject: Re: Tyco DPV-1 Dry valves We have upgraded several dry valves to the DPV-1 valve. They trip faster, & use less air pressure. Normally, we do not use the inspectors by-pass valve, doing a full or partial trip instead. Does there seem to be a problem when doing a full or a partial trip? When you clean the orifice, do you use a screwdriver or a brush to remove the water deposits?
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