Pumps and Glycol Solutions

Just completed two webinars; one on the use of glycols as heat transfer fluids and the other on retrofitting pumps in HVAC applications.  Both of these topics are related in that pumps are used to circulate fluids, including glycols, to transfer heat.  Typical applications for glycol use include the food and beverage industry, HVAC, and process chemical.  Pumps applications not only include the previously stated industries but also, utility; both electrical and water, petrochemical, and plastics, to name a few.  Insurance carriers that cover businesses in these industries need to be concerned because property damage as well as personal injury can occur when spills and pump failures occur.  Corrosion is a major problem in systems using carbon steel piping as a conduit for the transmission of the gylcol.  If not properly mixed and the correct inhibitors added, the glycol solution can be acidic and cause wear to occur in pipes and fittings resulting in leaks and spills, if not carefully monitored.  Similarly, the internal components of pumps can come under attack and fail as a result of the acidic conditions that could arise if the glycol solution is not properly mixed.  However, during such instances, insurance carriers are also considering the possibility of subrogating against a third party in order to recover their expenditures.  Potential defendants would include the company mixing and/or installing the glycol solution, the designer and installer of the piping system, and the selector and installer of the pump used in circulating the glycol.  It should be noted that the internal components of the pump can be selected based on compatibility of the fluid to be circulated.

Electric Power Steering

In a previous blog article, I discussed how complicated products were becoming as a result of the rapidly changing technology industry.  In another example of complex technology, electric power steering is replacing hydraulic power steering.  For the most part, this isn’t news.  Two years ago however, GM began recalling 2010 Chevrolet Cobalt vehicles because the power steering motor would fail.  Keep in mind that in a hydraulic system, pressurized fluid would assist the driver in turning the front wheels either left or right.  In an electric system, the power steering motor does this job.  But, when it fails, power steering disappears.  When power steering disappears, more effort is required from the driver in order to maintain control of the vehicle.  If the driver is unprepared for the additional strength required, then the risk of a crash increases. This is also true for a hydraulic system.  It is understood that the power steering motor depends upon input from sensor(s) in order to determine the steering wheel’s position and whether to move the front wheels right or left.  GM has stated in their recall that the power assist will return the next time that the vehicle is restarted.  This statement implies that somehow, something in the motor has a tendency to fix itself and return to normal until the next time the “something” decides to cause the motor to fail.  It should be noted that although not proven, the power steering motor might have a tendency to alternately stop operating and then start again causing the steering wheel to oscillate back and forth. Doing so, will likely cause the vehicle to move sideways, back and forth.  We are investigating a situation with just this type of movement.  Just one more thing for the driving public to have to worry about. If you have experienced a power steering problem you are urged to have it checked.  The recall for this vehicle can be seen on the NHTSA website or on the GM website.

Be Careful How You Treat Your Engineering Investigator!

Consider the following incident involving a vehicular impact and damage to the vehicle’s transmission. Assume that the driver hit an object in the road and claimed that the object caused damage to the transmission’s oil pan.  In short, fluid leaked out and the transmission was ruined.  On the surface, this seems like a plausible scenario and it would be reasonable to conclude that the failure of the transmission could occur after being hit by flying debris from the object that was struck.  However, what if evidence was found to indicate that things were not  as they appeared?  Needles to say, the final conclusions went against the owner’s claim.  Understandably, the owner would be upset and most likely not open to an alternative explanation.  If you are trying to get your insurance company to pay off on a claim, the last thing you want to do is insult the investigator.  The investigator has no interest in the outcome of the settlement between you and your insurer.  As a result, if you accuse the investigator of acting improperly with no evidence to support your accusation, neither the investigator or your insurer is going to feel inclined to help you in any way.  Not many people know this but, whenever a claim arises, the policyholder can hire their own engineer, appraiser, adjuster, attorney and anyone else they need to help prove their claim.  However, professional help does cost which is why insurers are seldom opposed in the claims process.  So, when you are faced with talking to an engineer, adjuster, appraiser or anyone else hired by and insurance company, be as polite and honest as you can be.  If you disagree with something, you can ask questions but, don’t insult or accuse the inverstigator of taking a “kickback”.  Instead, the time for an appeal ccomes after the initital decision is made by the insurer.  After that, appeals can be made directly to the insurer.  If there is  no satisfaction, then file a complaint with your state consumers affairs department or the office that regulates insurance companies.

Runaround Coil Heat Recovery

With all the talk about green house gases and oil dependency, energy efficiency and specifically, energy savings, is a top consideration these days.  One of the things that you don’t hear about too often is something called a “runaround” coil.  The system isn’t really limited to a coil but, instead describes a very simple  system for absorbing heat from one air stream and rejecting it to another.  Consider a large office building or hospital application where 100% outside air is conditioned, distributed to the individual spaces, and then completely exhausted.  A runaround system is nothing more than two heat transfer coils, one positioned in the inlet air stream ahead of the conditioning coils, and the other in the exhaust air stream.  The two coils are connected by piping in which water or a glycol solution is circulated by a centrifugal pump, hence the name “runaround”.  During the summer when outdoor air temperatures can reach into the 90s and 100s, the fluid in the runaround system absorbs heat from the outside air and in the process, cools it to a certain temperature.  The heat carried by the fluid is then circulated to the coil in the exhaust air stream where it is rejected to the air.  Heat rejection occurs because the exhaust air is at a temperature lower than that of  the fluid stream.  Significant energy savings occur when the cooling requirements of the building can be reduced.  For example, a building without a runaround system has a 100 ton load.  In order to meet the load, the cooling equipment has to cool outside air from 95 to 55 degrees.  Precooling of the outside air by 5 degrees (90 degrees) reduces the load on the cooling equipment to approximately 87 tons.  Dropping the cooling requirement by 13 tons can result in significant electrical energy cost savings.  Now, what happens if evaporative cooling is employed in the exhaust air stream? If an evaporative cooler is added upstream of the runaround coil, then the air stream can be cooled further resulting in an increased heat transfer rate from the fluid to the air stream, further reducing the cooling capacity requirements of the cooling equipment.   The use of a runaround coil is not a novel idea but one whose time is coming.

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