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
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
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
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
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
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
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
This is a case study about an incident I investigated involving a major upset in a distillation column. This blog builds on the previous blogs about the Distributed Control System, DCS – Data is the Key.
Distillation is a method of separating mixtures of compounds with differing boiling points. Uncle Bill with his still on the hill separates ethanol, that boils at 173°F, from water that boils at 212°F. If the mixture is heated to above 173°F, but below 212°F, the ethanol will boil, the vapor will travel up out of the unit and then can be condensed and served over ice with an olive… Any mixture of two or more chemicals with different boiling points can be separated in this way. The distillation Read More
