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 Read More
As an experienced safety consultant, I’m called on to investigate a wide range of premises liability incidents. One common premises liability incident that often results in serious injury is a fall on an improperly painted or maintained walking surface.
Slip and fall accidents are a common occurrence and can lead to serious injuries and even death. Painted surfaces are one of the most Read 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. Read More
As the Holiday Season approaches in the United States, it is a good time to take a look at several ways that the festivities can go awry.
For people that have cool or cold weather during winter, the thought of a warm, cozy home can be very comforting. However, many of the things that come to mind can turn the season on its head very quickly. Candles are a great example of a decorating trend with potentially serious side effects. The good folks at the National Fire Protection Association (NFPA) tell us that more than one-third of home decoration fires are started by candles, with more than two of every five decoration fires occurring because decorations were placed too close to a heat source. One fire I responded to as a firefighter occurred because Read More
Previously, Warren posted the first installment of a series on losses associated with heating systems. The first article looked at central forced air furnaces. This new article will look at a common form of supplemental or secondary heat, oil filled electric radiant heaters. These heaters are commonly used to provide extra heating in areas that are lacking in central heating capacity. Another rationale for their use arises from manufacturer’s claims that the portable heating units can lower your power bill. This is based on Read More
An unexpected severe winter freeze will remind many people and businesses that when water in a pipe freezes, the ice will expand and burst the pipe or pipe fitting. Large losses will result from flooding when the temperatures rise. Insulation will help, but not prevent freezing. Insulation simply slows down the rate of heat loss. The time of exposure to subfreezing temperature is an important factor.
The American Society of Refrigeration and Air Conditioning Engineers (ASHRAE) Handbook of Fundamentals has a short entry on the topic (Chapter 23, page 23.5-6), which gives an equation for estimating the time that it will take an insulated pipe to freeze, Read More
Temporary wiring is just that….temporary, and is typically used for repair and maintenance projects. In this blog I am going to discuss guidance offered by Article 590 of the National Electric Code (NEC), as well as some points to consider when using temporary wiring, including extension cords and holiday lighting.
Before each use, extension cords need to be inspected for visual damage. Cords with cuts or splits to the insulation need to be discarded. Cords with damage to the connectors, including those that feel loose when connected, need to be taken out of service. Failure to properly select and use extension cords can have a catastrophic result. Read More
In the old-timey Fire Triangle, you have heat, fuel, and oxygen. Get these three together in the right quantities, and you get fire. What if the fuel provides its own heat? That’s spontaneous combustion, or spontaneous ignition. NFPA921 defines this as “initiation of combustion of a material by an internal chemical or biological reaction that has produced sufficient heat to ignite the material.” Read More
The fire service affords you the opportunity to witness and observe things that a lot of engineers and even most people do not get the chance to see. An example of this is the situation where extended elevated temperatures combined with poor construction techniques to result in a structure fire.
I have personally observed several occasions where a structure fire was initiated due to improper construction of the fireplace hearth extension. The most recent one followed a multi-day cold snap, at least by South Carolina standards. The thermometer read 17 degrees F as I drove to the call of smoke in a residence Read More
There are few things as comforting to me during the winter months as a warm fire burning in the fireplace. And in this case, I am talking the real deal, the kind that warms you multiple times; from cutting, splitting and stacking the firewood until finally lighting a fire in the fireplace. However, just like your parents taught you, fire can be dangerous. And having an actual fire in your home fireplace comes with some required maintenance to ensure you can safely control the fire and keep it where it belongs. Read More
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