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.

Advertisements

Ram Truck Recall

Fiat Chrysler has announced that it is recalling approximately 494,000 medium and heavy duty Ram trucks for a problem with a water pump.  Approximately 443,000 trucks are in the United States.  The recall applies to 2013-2017 Ram 2500 and 3500 trucks equipped with 6.7 liter engines.  The recall also affects vehicles built with 3500, 4500 and 5500 chassis cabs.  The problem with the water pump is that the pump is equipped with a certain type of bearing that can overheat and cause a fire.  Fiat will begin notification of owners when service is available although there has been no indication of when that will take place.  For additional information, owners can contact Fiat Chrysler Automobiles at 1-800-853-1403.

What’s Going On?

Just completed an investigation into why the mast of a rock drilling machine came crashing down on the machine with no warning.  If you’ve ever seen a rock drilling machine, they are equipped with a mast that rests in a horizontal position and can be raised into a vertical position for drilling.  In this particular case, the mast was in the process of being lowered when four bolts failed at the pivot points where the mast rotates from the vertical to horizontal.  Looks like it was just one of those unfortunate things that happens.  Currently conducting an investigation into why the electrical system in a cement mixing truck appears to have short circuited and burned some of the wiring.

Eight Deaths – Really?

We’ve all heard about the eight people who lost their lives at the Rehabilitation Center in Hollywood Florida.  We’ve also heard about how the Center lost power and as a result, also lost their air conditioning.  The loss of power as a result of Hurricane Irma was not unusual.  With all the destruction, it would have been unusual if they hadn’t lost power.  For several days before the hurricane made landfall the whole country was hearing about Hurricane Irma and how destructive the storm could be.  For at least one week, the staff of the facility had time to prepare for the storm.  Granted, nobody knew where the storm would hit, how much damage would result, how much rain would fall or how bad flooding would be.  Knowing that a major storm was about to hit, it’s hard to believe that the staff didn’t plan to have extra water, food, and medicine on hand just in case it was needed.  Surely, the staff recognized the need to have extra batteries available for electronic medicine dispensing machines, oxygen monitors, vital sign monitors, and the like.  So, how is it that a critical necessity like electric power is overlooked?  Did the center not have a backup power generation system?  If not, why couldn’t they have rented a couple of generators before the storm?  In both cases, the backups would most likely have required the storage of gasoline in order to be prepared for a power outage.  In all fairness, the storage of gasoline could have been as dangerous to patients as the lack of cool air.  If the hurricane had damaged the facility, the stored gasoline could have been a huge fire hazard.  It’s easy to sit back, second guess and criticize those that were supposed to have been in attendance of the patients.  But, when the hazards are considered, choices have to be made.  To err on the side of caution is not necessarily a bad thing.  Food? Yes. Water? Yes. Medicine? Yes. Gasoline? Wait a minute!  Where will it be stored?  Can the stock be safely accessed if debris and flood water are in the area? Can generator fuel tanks be safely filled?  Can generators be safely operated without danger to staff or patients?  These and many more questions will be asked by investigators in order to determine if criminal charges are warranted.  Hopefully, those things that can be improved upon will be improved and staff as well as patients will be as well protected as can be during a major storm.  However, if negligence on the part of management or staff is found to have been a factor in the deaths of the eight patients, then criminal charges should be levied against the responsible people.

 

 

 

HVAC Equipment – Repair or Replace?

Following periods of extreme weather such as with hurricanes Harvey and Irma, the damage caused will invariably lead to questions posed by insurance adjusters of whether to repair or replace certain items.  Using HVAC equipment as an example, repair or replacement will depend on such things as the type of unit and the extent of damage compared with the cost for replacement.  Split systems have a condensing unit located outside while the air handler is located inside the building to be heated or cooled.  Condensing units will be exposed to wind and water and can experience damage while the air handling unit is less likely to see damage because it is protected to some extent by the structure in which it is located.  While flying debris and flooding can impact the condensing unit, the air handling unit may or may not become flooded depending on how close to floor level it is located.  The condensing unit part of a system contains the compressor, condenser coil, and some refrigerant piping.  All of these components are sealed and should not accept water.  However, condenser coils usually have fins that can become damaged if struck by debris carried through the air or water.  Similarly, refrigerant piping can become damaged and leak refrigerant if struck by debris.  If flooding is severe enough and the condensing unit is completely submerged, electrical components will be damaged.  Water can enter motors, relays and transformers.  All of which may or may not work on startup or work for a short time (a matter of months or less) and then fail.  As stated above, the damage to an air handler will depend on how close the unit is positioned to the floor.  Many times the air handler is a combination of a cooling coil and a gas or electric furnace.  If wall or attic mounted, the unit probably won’t sustain any damage.  However, if the unit is floor mounted it can be affected by water intrusion.  Here again, motors and controls will be the primary losses resulting in the need for replacement and not repair. If the air handler is a counterflow or downflow unit, then ductwork will also be damaged.  Sheet metal ductwork can be dried, cleaned and reinsulated but, flexible duct cannot.  This assumes that the ducts have not collapsed under the weight of the water.

For those applications where a packaged unit has been installed, whether on the ground or on a roof, the package itself is not sufficient to keep wind or water damage from occurring.  Packaged units are cooling units or cooling and heating units that have been combined into one “package”.  If installed on the ground, both wind and water can cause damage.  As with split systems, air or water borne debris can collide with the unit and damage the condenser coil necessitating repair and recharge. However, if the condenser has been damaged to the extent that it cannot be repaired, then the condenser will have to be replaced and the unit recharged.  It is also possible that a new condenser coil is no longer available from the manufacturer and as a result, the entire unit will have to be replaced.  Similarly, if the gas controls on the furnace side have been submerged, it is likely that they will malfunction, possibly leading to a dangerous and explosive scenario.  Needless to say it would be better to replace the gas controls (or the entire unit if necessary) in order to avoid further property damage and personal injury.  If the unit is mounted on a roof, it is more likely that the unit will sustain damage due to wind or is wind related.  Impact with flying debris is obvious and depending on the amount of damage, the cost to repair might be much less than the cost to replace the unit.  However, if the roof is blown away or collapses and takes a unit or several units, then those units will have to be replaced.  There is no point in reinstalling units that have been shaken, dropped, and otherwise “jostled”.  The cost to replace the unit(s) will certainly outweigh the cost to remove, repair obvious damage, reinstall and then troubleshoot the damaged unit(s).  The same reasoning applies to roof-mounted condensing units.

There is another type of HVAC unit that can also sustain wind or water damage: chillers.  A chiller is a large tonnage refrigeration unit typically found installed in multi-storey office buildings, university campuses, and factories.  Chillers can be installed at ground level or on roof-tops.  As a result, chillers are subject to the same wind and water perils.  However, chillers are made a little differently than conventional air cooled equipment.  Chillers are made so that all of the refrigeration components are inside one package but, instead of cooling air directly, the unit cools water that is circulated to a central station air handler or individual fan coil boxes.  Since chillers are physically large pieces of equipment, the physical size of the compressors, condenser coils and piping are larger than residential or commercial units and may or may not come in contact with flood water.  Debris could still cause damage to chiller frame supports and piping.  Once again, if water comes in contact with electric or electronic components, they will most likely have to be replaced.  Another characteristic of chillers is that not all chillers are air cooled, some are water cooled.  The implication being that a cooling tower is in use with the chiller unit.  A ground mounted cooling tower can be subject to damage by flood water.  Flood water carries all sorts of debris and if some of that debris makes its way into the supply line that carries cooling water to the condenser, the pump(s) impeller(s) and possibly the pumps themselves could sustain damage.  In order to use a cooling tower, the chiller has to have a special type of condenser. Instead of the fin and tube configuration used in air cooled units, water cooled units use a shell and tube configuration.  That is, a type of heat exchanger where the refrigerant flows through tubes encased in a steel shell and cooling water flows through the inside of the shell but on the exterior side of the tubes.  It is also possible for small solid objects like rocks to be carried into the condenser where they can create obstructions and possibly puncture tubes.  In order to determine the proper course of action, the condensers will have to be dismantled and inspected.  If the shell and the tubes are found undamaged, then the condensers can be cleaned and placed back in service.  If however, the tubes are damaged, the condenser will have to be replaced.  It should be noted that the condenser can be re-tubed but, this will involve weighing the cost of repair against replacement for this component.

As stated above, chillers can be connected to a central station air handler or fan coil boxes.  Central station air handlers are air moving devices that contain a motor driven blower and a combination of cooling only or cooling and heating coils.  Once again, these components are contained in a single package.  If flood water is going to cause damage, the air handler has be located in a part of the building that is low enough to allow flood water to enter the building and access the air moving equipment.  If the air handler is located in an upper floor that is above the level of flood water, then flood water will most likely not damage the unit.  The unit has to sustain damage in another way such as building collapse.  If flood water does enter the air handler, it will have to rise to the level where it can actually do damage.  Air handlers are physically large pieces of equipment and depending on the size, ladders may be necessary in order to reach motors, pulleys, belts, damper mechanisms, and controls.  Needing a ladder to service the unit shows that the water level might have to be quite high, say above 6 feet, to cause real damage. While water contact with the lower parts of the air handler, including the cooling and heating coils, can be cleaned; there is little damage that flood water can do unless the unit is practically submerged or there is a building damage that results in damage to the air handler.  If there is damage to a cooling or heating coil, the coils can be replaced and the system refilled with water if the remainder of the air handler is in good condition.

Finally, equipment varies from manufacturer to manufacturer and the component layout will vary.  The component position will determine what comes in contact with wind or water or both.  Those components that are deemed to have been damaged will drive the cost of repair and has to be evaluated on an individual basis.  The cost of repair then has to be weighed against the cost to replace the entire unit.

 

 

 

 

What Happened to Water and Gas Lines?

By now everyone has heard about the massive devastation caused by both hurricanes Harvey and Irma.  Nightly news reports have been showing us how much damage can be caused by hurricane force winds not to mention the water damage caused by the flooding rain.  Much of the reporting has been focused on people that have been displaced as a result of the storms.  But, not much if anything has been said about the hidden damage to the infrastructure.  Yes, we are all aware of damaged roads and downed power lines.  But what about the damage to the water supply, storm drains and sewer systems?  Because of all the debris and mud, flowing water will carry those solid substances through pipelines to pumps.  The impact can cause damage to impellers, valves, and filters.  Debris can also become trapped inside pipelines where the pipelines bend causing a backup, if not rupture, and possibly necessitating the replacement of line segments.  Before potable water service can be restored, all contaminants will have to be removed and the flow of water through drainage systems will have to be confirmed before the public can be allowed access.   What about natural gas service?  Gas lines can either be routed above or below ground.  The main problem to consider is sink holes.  This is especially true in Florida.  Unsupported gas or water lines can fail if the ground beneath collapses to form a large crater.  With as much as rain as Texas and Florida got during the storms, it would be prudent for utility engineers to be especially mindful of the potential hazards that could develop if sink holes start appearing.

 

Volkswagen Recalls CC and Passat Vehicles

Volkswagen has announced that it is recalling approximately 280,915 CC and Passat sedans and wagons for a problem with the fuel pump control module. The engines in these vehicles can stall as a result of the loss of power to the fuel pump module.  The loss of power means that fuel flow to the engine will cease causing the engine to stall and increasing the possibility of a collision.  In addition, the fuel pump module can remain running after the ignition is turned off.  All of the vehicles involved in this recall are equipped with four cylinder engines.  The vehicles involved in this recall are 2009 to 2016 Volkswagen CC and 2006 to 2010 Volkswagen Passat.  Volkswagen will begin owner notification in October and will send a second letter to owners advising of the date of availability of the replacement fuel pump modules.  For additional information, owners can contact Volkswagen customer service directly by calling 1-800-893-5298.  Owners should refer to Volkswagen recall number 20AE.

%d bloggers like this: