In my last blog, we discussed the small PRVs that go on wet sprinkler systems to limit their pressure below 175 psi. That brought to mind a small PRV in another application that is used to keep something different cool: an electric motor-driven centrifugal fire pump. I can’t talk about electric fire pumps without also talking about diesel fire pumps, so let’s dive in and take a look at both! Read More
An afternoon summer rain shower led to an elderly woman’s admittance to the hospital. Mrs. Jones, aged 68, entered a retail store to buy groceries for her visiting family. Mrs. Jones walked through the store’s vestibule toward the entrance where she slipped and fell, sustaining significant injuries. An investigation was conducted to determine the cause of the slip and fall incident.
Falls were the number one cause of preventable non-fatal injuries and the number two cause of preventable deaths in the US in 2019 (CDC and NEISS data). Slip and falls occur when there is an unexpected loss of traction between a person’s foot and the walking surface. Slip and falls are common and can occur in any setting where people walk, including homes, workplaces, and public areas. Slip and falls can result in serious injuries, particularly for older adults.
The human gait cycle consists of four phases: Read 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 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
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.Read 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. Read 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. Read More
Ladders…not a particularly exciting topic I’ll admit. But hey, we need ladders to help us accomplish all kinds of tasks. Most people have used at least one of the many types of ladders that are available today. And the odds are probably pretty good that many of those users strayed outside the limits of safety a time or two while on a ladder. It is amazing the risks some people will take to save some time or avoid the inconvenience of getting down to move the ladder into a safer position. I wonder how many of those risks would be taken on a ladder if the users knew they were on camera.
Think about astronaut Neil Armstrong. He travelled by rocket almost 239,000 miles through space and Read More