Statistics predict that about half grill owners will be firing them up this upcoming Memorial Day weekend [i]. Let’s look over a propane grill, as if we had just pulled it out for the grilling season, for some tips and red flags. Not beef tips or how to get the perfect sear on your steak – safety tips! Besides hot surfaces, a gas grill serves up hazards related to flammable gases: fires, explosions, and flash fires. (more…)
In Part 1, we looked at the basic parts of a fire sprinkler and took a closer look at other parts including heat responsive elements, wrench bosses, and kick springs. In this part, we’ll look at k-factors and deflectors.
K-Factor and Orifice Size
K-factor is a characteristic that relates water pressure to flow rate from the sprinkler, represented as k in the equation Q = k√P, where Q is flow (gpm) and P is pressure (psi).
If we supply water at 50 psi to a k-factor 5.6 sprinkler, the flow rate is 40 gpm. If we supply 50 psi water to a K25 sprinkler, the flow rate is 177 gpm. There are now sprinklers as large as K33.6, which would flow 238 gpm given 50 psi – big difference from the K5.6!
The most common k-factors are 5.6, 8.0, 11.2, 14, 16.8, 22.4 and 25. There are smaller and larger k-factors than these. For reference, K5.6 and possibly K8.0 are most often found in (more…)
In this blog we’ll take a look at the basic and some of the less-known parts of fire sprinklers, with more to come in a later post.
Here are the basic parts of the fire sprinkler, shown on a pendent glass bulb sprinkler and an upright solder element (“fusible link”) sprinkler:
Let’s take a closer look to learn about some of the less known parts, and also look at two types of sprinklers disassembled. Included in parentheses are some of the different names for some of these parts. (more…)
Cooking equipment is the leading cause and is responsible for over half of fires in eating and drinking establishments (see Warren expert Chad Jones’ 2020 blog, Structure Fires in Eating and Drinking Establishments, for further reading on fire causes and NFPA 96 on duct inspection and cleaning). Fire extinguishing systems are also routinely provided over GREASE-producing cooking appliances. So why are some of these fires still so bad? GREASE is the word.(more…)
In my two previous blogs, we first discussed wet sprinkler systems (Wet), the most basic and most common fire system type followed by dry sprinkler systems (Dry), which are a bit more complicated. Ratcheting up another level, in this last edition on sprinkler systems, let’s take a look together at preaction and deluge systems. These can be complex and variable, so we’ll operate at the 30,000 ft level. (more…)
In my previous blog , I discussed the most basic and most common fire system type: wet sprinkler systems. The possible failure areas discussed with wet systems will also apply to dry sprinkler systems (control valves closed, obstructions, issues in the system, installation, or deficiencies with inspection, testing, and maintenance). Dry systems are even more prone to obstructions than wet systems, so close attention should be paid to that possibility. (more…)
After a major fire, it is necessary to investigate the fire sprinkler system to see if and why it malfunctioned. Wet sprinkler systems are the most common and least complex fire sprinkler systems in use. The following are major items addressed in an investigation involving a wet system.
If available, drawings of the supply piping and sprinkler system are helpful. If these are not available, a sketch of the system will be made. Requests will also be made for inspection, testing, and maintenance documentation as well as fire alarm logs.
The top reason that fire sprinkler systems do not function correctly during a fire is (more…)
Please join us in welcoming Fire Protection Engineer Amy Anderson, P.E., to the WARREN family! Amy has over 20 years of property loss prevention engineering and experience, specializing in fire protection. Amy graduated from Clemson University with a degree in Chemical Engineering and is a licensed Professional Engineer in Fire Protection.