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  1. RainbowFS

    The effect fire sprinklers have on insurance rates.

    Insurance against water damage can be more than fire insurance. I was recently told by an owner that was required to retrofit sprinklers in his small manufacturing plant that his property insurance rates were going up significantly specifically because of the threat of water damage. Alex Traw...
  2. RainbowFS

    Is there anything in the standards that addresses riser manifolds?

    I service several (fairly recently built) Lowe's locations and they all have seven systems on a single manifold behind a huge pump. As for a "master" flow switch, if the pump is upstream of the systems, wouldn't the pump alarm serve as your alarm for the entire building? I may be assuming too...
  3. RainbowFS

    Antifreeze loop- RPZ backflow required or double check ok?

    I've been installing RPZ devices on antifreeze loops for years and I understand the principles of cross connection prevention. We service a "problem child" system that has an antifreeze system above the ceiling in a lobby of high traffic business. The RPZ is just inches above the grid and there...
  4. RainbowFS

    Dilemma- sprinkler addition on a gridded dry system.

    I've got a 1973 copy of 13, and 5-2.3.1 has no mention of gridded systems. Yeah, I've been reading through other parts of the 1973 handbook, just to get some perspective, not to mention that it's a quick read. The old style line drawings and the overall brevity invokes a word I seldom use; it...
  5. RainbowFS

    Dilemma- sprinkler addition on a gridded dry system.

    Thanks SD2 for the wealth of information. I'm reading through the article now but your example is fascinating and like you say, counterinuitive from everything I've learned. So, my system dates to 1989. Looking at the trip test record, other than one noted accelerator failure, water to test...
  6. RainbowFS

    Dilemma- sprinkler addition on a gridded dry system.

    I was kind of kidding when I called it a gang drain. It isn't. I'm sure it was designed as a bulk main as if it was a wet system. I'm assuming the calcs were done manually and that the numbers on the data plate really don't mean much. I think my calc software would reject this design if I...
  7. RainbowFS

    Dilemma- sprinkler addition on a gridded dry system.

    Situation- An existing (circa 1983) 29,400 sq ft open warehouse (235' E-W x 125' N-S) with a 6" dry system. The riser is in the NE corner of the bldg. The new owner wants to add 2,800 sq ft of offices in the SW corner. No problems so far... The problem is that the dry system is gridded and...
  8. RainbowFS

    Sidewall Sprinkler Head with Pendant Sprinkler in Coverage Area

    I didn't go to the pic, but if the pendent head is within three inches of the wall , can't it just be changed to a vertical sidewall head and call it good? Alex Traw Rainbow Fire Sprinklers Albany, Oregon
  9. RainbowFS

    13R calcs and 600 sq ft compartments

    Thanks. Yes, I did some further reading and the distinction of the compartments with beams or without was unclear to me. Reading code language can be a struggle, with them trying to be as unambiguous as possible yet still leaving things unclear. That's my own issue, though. FWIW, the sleeping...
  10. RainbowFS

    13R calcs and 600 sq ft compartments

    I'm looking at an old frat house that needs sprinklers. It's part of an overall "refreshing" of the building. They call for a 13R system. The basement and two floors up avg 2,800 sq ft and then a top floor is one big room where all the boys sleep, about 1235 sq ft. This is a typical frat design...
  11. RainbowFS

    PSCIPCo. M2 Hydrant Resources?

    To add- Calls to the manufacturer and sister companies (Clow, McWane, Mueller) have been fruitless. Alex Traw Rainbow Fire Sprinklers Albany, Oregon
  12. RainbowFS

    PSCIPCo. M2 Hydrant Resources?

    I have a site with nine Pacific States Cast Iron Pipe Company (PSCIPCO) M2 hydrants of 1971-1975 vintage. This is a Corey, or toggle type hydrant and it's clear to me that it is an obsolete model but I can't even find a decent diagram of one. The problem is that one of them is broken, or I...
  13. RainbowFS

    Current or Former AHJ Input Requested - NFPA25 Inspection Failure Building Modifications

    We conduct inspections and note deficiencies based on the code that was current when the system was installed. The first time we inspect a site we take it at face value. Some older places have multiple (often connected) buildings with a sprinklers in one and not the other, or maybe it's an...
  14. RainbowFS

    Central sprinklers slipping seats seeping suspiciously

    I stated in my post the difference between the O-ring heads (recalled) and the Belleville style brass on brass seat (not recalled). The neoprene O-ring would swell when exposed to oil (as in thread cutting oil)and cause the seat to not fall out when the fusible link broke, hence the recall...
  15. RainbowFS

    Central sprinklers slipping seats seeping suspiciously

    Sorry for the tongue twister. This is more of a field observation and I'm curious whether anyone else has encountered a similar problem. Focus- systems built from the late '80's into the '90's and equipped with Central/Gem with Belleville (brass cup) seats. Back story- I'm sure most on here...
  16. RainbowFS

    Antifreeze replacement schedule?

    Is there a specified schedule for antifreeze replacement? A respected colleague swears that antifreeze is to be replaced every 10 years, but can't cite the code. I can't find anything in NFPA 25 stating anything about antifreeze longevity. I have a good number of antifreeze systems to service...
  17. RainbowFS

    Is galvanized pipe req'd on an addition to existing?

    I am doing an addition to a dry pipe sprinkler system built circa 1986. It's a tall steel warehouse and a mezzanine with offices is going in one end. We'll be running all new lines off of a new mechanical tee on the riser. My question is- since the old system is all black pipe, can I use black...
  18. RainbowFS

    Discharge pressures for standard spray heads?

    Back when I first started doing calculations I was told that when calculating sprinklers that I need to strive for a minimum of 14 psi regardless of required flow. We often do jobs in smaller towns with not so robust water flow figures. When possible I will reduce the K factor to bring my...
  19. RainbowFS

    choose pendent or upright sprinklers?

    I prefer uprights because the line below serves to protect the head from potential damage. Because the customer will always manage to do the strangest things to their sprinkler systems, so anything we can do to prevent it may help. Alex Traw Rainbow Fire Sprinklers Albany, Oregon
  20. RainbowFS

    Estimating "rules of thumb" for FP systems

    I've been a sprinkler contractor for 20+ years. We're small, like me and my brother small. The biggest job I've ever had was $140,000. When we bid we do a rough materials list, head count, and estimate the time to fit it, which varies depending on the style of building. We're fairly inexpensive...

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