Dry pipe with attic heads

[cdafd]

Dry pipe over 500 gallons with attic heads having to meet 60 second rule

Dry pipe by itself being over 500 gallons needs a quick opening device anyway?

And because of the attic heads in use total system still has to meet 60 second rule???

Thanks

 

[skdesigner]

If the system is between 500 and 750 Gal, you don't NEED an accelerator. Just that if you don't have one, you need to meet the required water delivery time. Anything over 750 and you need to meet the required time no matter what. I scanned through the tyco datasheets and didn't see anything requiring meeting a certain delivery time where NFPA 13 would not.

 

[cdafd]

thanks the "AP" and "BB1 4.5" have delivery times


how about 7.2.3.4 for systems 501 to 750??? I read it to say the 60 second is not required if you have a quick opening device.

using 2010 edition

 

[skdesigner]

I missed that in the datasheet, you're absolutely right.

Also correct about the quick opening device negating a specific delivery time. BUT, given that accelerators are generally an in-stock item and fairly easy to plum into the dry trim after the fact - I don't buy an accelerator and have the boys trim the dry valve without it. When it comes to test time, we snap the inspectors test open...if the water gets there in under 60 seconds, bobs your uncle and thanks for the $350 savings. If the water doesn't get there in time, send an apprentice over to the supplier and pick up an accelerator. A good journeyman can plumb it into the trim in less than 1 hour, and we're no worse off than when we started.

 

[cdafd]

thanks then will write the comment that way 60 sec or provide device, except where attic heads require it.

reviewing 16 different apt buildings