Forensic Engineers and Consultants

Archive: Industrial

Know a Fire Sprinkler, Like a Boss – Part 2

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

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Know a Fire Sprinkler, Like a Boss – Part 1

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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

Scared of Water, or Prefer to Get Drenched? Fire Suppression with Preaction and Deluge Systems

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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

When a DRY Fire Sprinkler System Leaves You Soaked

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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

HEY…Cover Up Please!

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Machine guards can be compared to the clothes we wear every day.  Indeed, they serve a very important purpose.  Imagine someone leaving their home on a fine, sunny morning wearing nothing but a smile.  Wonder how far they will get through the day before things start going poorly for this individual?

 

 

 

 

 

There will be more than a few raised eyebrows and blushes when he stops into the local Starbucks for his usual morning double-dipped and whipped, chocolaty chip with a touch of pumpkin spice cappuccino fix.  Good luck with that!  Probably going to leave disappointed, empty-handed, and likely wearing handcuffs.  This will be the beginning of a very long, very bad day for that individual.  Had he recognized the risks associated with this type of behavior, and then put forth a little effort to cover up, he would have prevented many unfavorable and possibly life-changing personal and legal problems from ever occurring!

And so it is with properly guarding a machine.  Machine safeguarding helps to protect workers from preventable injuries. Read More

WARREN Welcomes Mechanical Engineer Bob Hickman, P.E.

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Please join us in welcoming Mechanical Engineer Bob Hickman, P.E., to the WARREN family! Bob has over 30 years of manufacturing and machine design experience in production and quality-driven environments. Bob holds a Bachelor of Science in Mechanical Engineering from Clemson University.

Bob’s Areas of Expertise Include:
-Machine Safeguarding
-Machine Design
-Equipment Failure
-Mechanical Engineering
-Industrial Accident Investigation
-Codes & Standards
-Machinery & Equipment Damage Assessment
-Products Liability Read More

The Concepts of Hazard, Risk, and Harm in Machine Safeguarding

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Hazard, risk, and harm are terms that are used in the world of machine safeguarding.   How do these words shape the concept of machine safeguarding? Let’s look a little deeper….

Hazard, which Merriam-Webster defines as a noun, lists its first meaning as a source of danger.

1: a source of danger

2a: the effect of unpredictable and unanalyzable forces in determining events : CHANCE, RISK

  b:  a chance event : ACCIDENT  Read More

How Long Before the Pipes Freeze?

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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

T is for Temporary – Issues with Extension Cords and Other Temporary Wiring Applications

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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

Conveyor Backstops: Sometimes One Isn’t Enough, Part 1

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This is the first of a two-part blog series describing an incident involving conveying machinery that seriously injured a miner. Part 1 describes the machinery and the incident. In Part 2 I will summarize my engineering analysis of the incident and share the conclusions I reached.

A loaded, inclined conveyor belt may contain hazardous levels of energy due to gravity. To protect workers, anti-reverse devices called backstops are installed on inclined conveyors to prevent unexpected downhill movement. The Conveyor Equipment Manufacturer’s Association (CEMA) defines a backstop as: Read More

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