MEC&F Expert Engineers : 12/25/14

Thursday, December 25, 2014

PROTECT YOUR PIPES FROM BURSTING THIS WINTER



Freeze-Up and Burst Water Pipes WATER DAMAGE Claims
http://metroforensics.blogspot.com/2014/11/freeze-up-and-burst-water-pipes-water.html


Compliments of the “polar vortex”, frigid temperatures in the Northeast and in the Southern States have caused many water pipes to freeze and burst.  Residential and commercial properties have been affected.  Pipe freeze-up and unfreezing damages were particularly severe in southern climates, where piping systems lack freeze protection more common in the north.  Even in the Northeast, property owners saw (and continue to see) significant pipe failures.  In some cases, fire sprinkler systems froze, allowing fire to spread due to the lack of fire protection.  Malls, restaurants and other walk-in retail establishments suffered business interruption, and some lost power as well as other utility services.
Most standard plumbing codes reference guidelines or standards in recognizing freezing of most buildings.  Typically, they are as follows:
“A water, soil, or waste pipe shall not be installed or permitted outside of a building, or concealed in outside walls or in any space where they may be subjected to freezing temperature, unless adequate provision is made to protect them from freezing.”
In your evaluation and investigation of these types of cases, you should keep in mind the absolute cause of the freeze up and determine whether or not there are issues concerning coverage, liabilities, subrogation, and ultimately evaluate the damage to determine extent of damage and reasonable cost for repair or replacement of these items.
We had already assignments for a frozen pipe activating a sprinkler system which flooded the insured’s property.  Both MSO and ISO policies contain general mitigation of damages provisions requiring insureds to take reasonable efforts to prevent further losses from occurring, such winterize the pipes in the home, maintain heat, etc. 
Ex.:  ISO Form HO 00 06 says:

We do not insure, however, for loss:
C       Caused by:
(1)    Freezing of a plumbing, heating, air conditioning or automatic fire protective sprinkler system or of a household appliance, or by discharge, leakage or overflow from within the system or appliance caused by freezing. This exclusion does not apply if you have used reasonable care to:
(a)    Maintain heat in the building; or
(b)    Shut off the water supply and drain all systems and appliances of water.
The insurance industry is presented with claims that surround freezing of water pipes that ultimately burst and result in property damage claims.  There are many causes for these claims, some of which involve the following:
1.    Improper maintenance of heat in a building or chase way (occupied or vacant).
2.    Sudden shutdown of heating system, combined with improper inspection or maintaining of heat in a building.
3.    Deterioration or lack of insulation protecting building and water piping.
4.    Mechanical or electrical malfunction of a control or product.
5.    Inadequate servicing and maintaining of piping, whether considered to be part of constant wet or water flow piping, and/or a dry pipe system, which normally does not allow constant water pressurization.



As the action or inaction of the insured is critical in determining whether coverage applies, a thorough examination of the circumstances of the loss is crucial:  these claims are fact-sensitive and we can assist you in properly developing them.
Burst pipes, flooded basements, devastating structural damage, damaged floors, ceilings, carpets, wiring, furnishings, wallboard, and mold are a few obvious results of freeze up and pipe burst damage.  These types of problems can result from maintenance problems, mechanical failure, installation errors, low temperatures maintained in buildings, or fuel delivery issues.  Be sure to learn more about METROPOLITAN’s proprietary Fuel Usage Analysis Computer Program. This computer program compares data we retrieve with energy consumption levels to validate the results of our investigation.



Why do water pipes burst in winter?

The pipe bursts always in a longitudinal fashion.   The burst always occurs at the weakest portion of the pipe.  Because of its unique properties, water expands as it freezes into ice by as much as nine percent (9%) in volume.  On the other hand, a metal pipe shrinks when frozen.  In a pipe, ice forms first on the inside wall of the pipe and grows radially inward until there is a solid plug of ice blocking the pipe. Until that situation occurs, the expansion of the freezing water in the pipe merely pushes water back into the water main. When the plug of ice completely blocks the pipe, it seals water between the plug and a closed valve. If more ice forms between the plug and the closed valve, the expanding ice has nowhere to go, and causes the pipe to burst at its weakest point.  Hot water pipes will burst much faster than the cold water pipes.
Pipe bursting occurs when
(1) Freezing temperatures create ice blockages in water pipes, then (2) Further ice growth applies dangerously high pressures to a confined water volume.
Most of the research and claims investigated by METROPOLITAN uncovers results that examine the effect upon the freezing process of five variables:
1.   Design temperature.
2.   Pipe composition, (copper or PVC).
3.   Insulation level.
4.   Pipe diameter ( 1/2” or 3/4”).
5.   Water source (cold or hot water tap).

The Freezing events in a water pipe can be sub-divided into four distinct stages:
1.   Initial cooling through super cooling.
2.   Dendritic ice formation.
3.   Annular ice formation.
4.   Final cooling to ambient temperature.

Timetables for freezing temperatures can vary, but the testing performed by the University of Illinois confirms the following:
When a water pipe is exposed to subfreezing temperatures, heat is transferred from the water, through the pipe wall and any insulation layers to the sub-freezing air.  The temperature of the water begins to fall in a steep decline. Remarkably, the water in the pipe does not immediately begin to freeze when it reaches the phase change temperature of zero degrees Celsius, but continues to fall and approach the temperature of the surrounding air.
This process is known as super cooling. It is possible for water in a pipe to super cool for a considerable length of time before any ice forms. The temperature at which ice begins to form is known as the ice nucleation temperature. The nucleation temperature implies a starting, or a nucleus, for ice formation. It is often claimed that, when subjected to identical conditions, a hot water line will burst before a cold water line. One theory states that premature bursting is the result of greater dendritic ice formation in hot water pipes than in cold water pipes.



However, testing of water drawn from both cold and hot water taps revealed that at the time of bursting, there was no difference if the water was drawn from a cold water source or a hot water source.  Further research and investigation is required, but it is believed that a tendency for hot water pipes to burst before cold water pipes might be due to the distribution of entrapped air in residential water systems because of water heating processes.  Clearly, you should be aware that the source of the freezing temperature could be the overall environment, a broken window, or uninsulated pipe exposed to the obvious temperatures.   What occurs is an ice formation pattern in which there is the expansion of ice, or the growth of ice, through the pipe.   As the pipe continues to freeze, particularly in a vertical situation, the frontier of the ice/water climbs in the pipe.   At the same time annular ice against the pipe wall grows inward.



The Forensic Investigation
It is METROPOLITAN’s experience that there is no substitute for a thorough and comprehensive inspection of the structures to determine the number of conditions that caused the loss and whether the conditions worked independently, concurrently, or in a sequence to cause the damage.  For example, some common questions include:
·         Was the pipe frozen and burst due to lack of maintenance, wear and tear or incorrect installation? E.g., old or corroded pipes, or no proper insulation, etc.
·         Was the frozen pipe damaged due to negligence? did the insured turn off the heat in the home or commercial property during cold weather?
·         Did the boiler or furnace shutdown and caused the pipe freeze-up?  Did the boiler or furnace had a mechanical breakdown or it was shut down by the insured?  METROPOLITAN can reveal the causes of these failures utilizing mechanical evaluation of the boiler or furnace, perform a fuel usage analysis and perform an examination of the condition of the equipment installation.  We can also determine the thermostat setting temperature, or whether the fuel run out, along with the timing of these events.  METROPOLITAN will obtain a copy of the insured’s utility bill and will audit it for the purpose of making the above determinations.  Our Energy and Fuel Usage Modeling will determine what really happened and determine the cause of the pipe burst.
·         Was the pipe broken due to normal wear and tear?
A comprehensive investigation is crucial to good claims handling.  It is vitally important to conduct bench testing of boiler controls and a Comprehensive Freeze Up Loss Investigation for freeze up losses.  Courts have ruled against companies that have skimped on their investigations and rushed coverage decisions in these types of losses.  Our clients require prompt and thorough claims investigation and fact finding and METROPOLITAN delivers high quality services at a highly competitive price.



It’s getting colder and with that cold comes the hassle of frozen / broken pipes, if you don’t take a few precautions. Here are a few winterizing tips that just might keep me from having to make a service call to your house.
Hose Bibs
#1 Disconnect all hoses from your hose bibs! Most hose bibs installed these days are frost free which shuts the water off inside the wall away from the outside cold but, if you do not disconnect the hose the water stays trapped in the spout. When the water freezes it expands and will damage the hose bib. This problem is usually discovered in the spring or summer when you turn on the bib for the first time and find water is coming out of your wall. Doing this will save you a costly repair.
#2 Hose bib covers.  You can get these at any of your local home improvement stores.  They are  foam, dome shaped covers you put over your hose bib.  These covers help keep the cold away from the hose bib. Hose bib covers are more important for non-frost free hose bibs but it wouldn’t hurt to put them an all of your outdoor faucets.  Putting these on will also help to remind you to disconnect your hoses.  These covers cost about 1-2 dollars and are a wise investment.

Insulate Piping
Many people often don’t realize the importance of insulating piping until it is too late and pipes are frozen and broken.  All pipes in crawl spaces and any piping that is exposed on the outside of buildings or above the ground needs to be insulated.  Pipes in garages that are not heated are also vulnerable to freezing in cold weather and should be insulated.

Pump Houses
All exposed piping in pump houses should be insulated. It is also important to have some heat in your pump house so your piping and pressure tank do not freeze.  Your local home improvement store will have several different options for you to help keep your pump house warm and your pressure tank and piping from freezing.  Items to look for or ask about are heat wire- this is wrapped around piping and warms up when plugged in.  It keeps your pipes from freezing. Heat lamps can also be installed near your pressure tank and piping and will help keep your pressure tank and piping warm to protect from freezing.  Both of these options can be plugged into a temperature sensing plug that turns on when it gets below a certain temperature and turns off when it gets above a higher temperature.  These can also be purchased at your local home improvement store and are another great defense against broken pipes and expensive repairs.


How to keep pipes from freezing when temperature is going to drop below 32 degrees:
#1 Trickle water from a sink or two to keep water moving in your plumbing system, moving water takes longer to freeze than water that is not moving, this will help keep pipes from freezing.

#2 Open cabinet doors under sinks to allow warm air from the room to get back into the cabinet where pipes are.

#3 Turn your heat up a little warmer than normal. Warmer rooms mean warmer walls, and warmer walls help keep the pipes in those walls from freezing.

#4 Cover foundation vents around bathrooms, kitchens and laundry rooms that are on exterior walls to help keep the cold out and away from the piping in these areas. You can buy pre-formed Styrofoam blocks that fit in standard foundation vents at your local home improvement store. These covers should be removed when the risk of freezing is over in order to allow cross ventilation in crawl space areas.

#5 makes sure that all piping in attics and crawl spaces are covered with insulation. A lot of houses have blown in insulation in attics which is fine but it tends to settle and expose pipes. If you have blown in insulation inspect insulation to make sure it has not settled and exposed piping. Batt insulation is a better choice in my opinion.

How to keep this from happening again:
#1 Make sure that all piping in attics and crawl spaces are covered with insulation.  We cannot stress this enough.  This is where we saw most of the burst pipes we investigated.  Most attics have blown in insulation and it settles over time exposing pipes.  Exposed pipes freeze and burst.

#2 In older homes that contain copper or galvanized piping consider replacing with PEX piping. PEX piping may freeze but it resists breakage.  In the 1000’s of investigations we have performed, not one break was PEX related.  However, I did cut out 100’s of feet of copper and galvanized pipe and fittings.



Metropolitan Engineering, Consulting & Forensics (MECF)
Providing Competent, Expert and Objective Investigative Engineering and Consulting Services
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CONTROLLING HAZARDOUS FUME AND GASES DURING WELDING



Controlling  Hazardous  Fume  and Gases  during Welding





Welding joins materials together by melting a metal work piece along with a filler metal to form a strong joint. The welding process produces visible smoke that contains harmful metal fume and gas by-products. This fact sheet discusses welding operations, applicable OSHA standards, and suggestions for protecting welders and coworkers from exposures to the many hazardous substances in welding fume.


Types of welding

Welding is classified into two groups: fusion (heat alone) or pressure (heat and pressure) welding.

There are three types of fusion welding: electric arc, gas and thermit.  Electric arc welding is the most widely used type of fusion welding.  It employs an electric arc to melt the base and filler metals. Arc welding types in order of decreasing fume production include:





·         Flux Core Arc Welding (FCAW) filler metal electrode; flux shield

·         Shielded Metal Arc (SMAW) electrode provides both flux and filler material

·         Gas Metal Arc (GMAW or MIG) widely used; consumable electrode for filler metal, external gas shield

·         Tungsten Inert Gas (GTAW or TIG) superior finish; non-consumable electrode; externally-supplied inert gas shield



 Gas or oxy-fuel welding uses a flame from burning a gas (usually acetylene) to melt metal at a joint to be welded, and is a common method for welding iron, steel, cast iron, and copper. Thermit welding uses a chemical reaction to produce intense heat instead of using gas fuel or electric current. Pressure welding uses heat along with impact-type pressure to join the pieces.

Oxy-fuel and plasma cutting, along with brazing, are related to welding as they all involve the melting of metal and the generation of airborne metal fume. Brazing is a metal-joining process where only the filler metal is melted.




 Welder using local exhaust ventilation to remove fume from breathing zone. (Photo courtesy of the Lincoln Electric Company).



What is in welding fume?

The following compounds can be present in the welding fume

Metals

Aluminum, Antimony, Arsenic, Beryllium, Cadmium, Chromium, Cobalt, Copper, Iron, Lead, Manganese, Molybdenum, Nickel, Silver, Tin, Titanium, Vanadium, Zinc.

Gases

Shielding—Argon, Helium, Nitrogen, Carbon Dioxide.

Process—Nitric Oxide, Nitrogen Dioxide, Carbon Monoxide, Ozone, Phosgene, Hydrogen Fluoride, Carbon Dioxide.

Factors that affect worker exposure to welding fume

• Type of welding process

• Base metal and filler metals used

• Welding rod composition

• Location (outside, enclosed space)

• Welder work practices

• Air movement

• Use of ventilation controls




Health effects of breathing welding fume

Acute exposure to welding fume and gases can result in eye, nose and throat irritation, dizziness and nausea. Workers in the area who experience these symptoms should leave the area immediately, seek fresh air and obtain medical attention.

Prolonged exposure to welding fume may cause lung damage and various types of cancer, including lung, larynx and urinary tract.

Health effects from certain fumes may include metal fume fever, stomach ulcers, kidney damage and nervous system damage. Prolonged exposure to manganese fume can cause Parkinson’s–like symptoms.

Gases such as helium, argon, and carbon dioxide displace oxygen in the air and can lead to suffocation, particularly when welding in confined or enclosed spaces. Carbon monoxide gas can form, posing a serious asphyxiation hazard.




Welding and Hexavalent Chromium

·         Chromium is a component in stainless steel, nonferrous alloys, chromate coatings and some welding consumables.

·         Chromium is converted to its hexavalent state, Cr(VI), during the welding process.

·         Cr(VI) fume is highly toxic and can damage the eyes, skin, nose, throat, and lungs and cause cancer.

·         OSHA regulates worker exposure to Cr(VI) under its Chromium (VI) standard, 29 CFR 1910.1026 and 1926.1126.

·         OSHA’s Permissible Exposure Limit (PEL) for Cr(VI) is 5 μg/m3 as an 8-hour time-weighted average.


Reducing exposure to welding fume

Welders should understand the hazards of the materials they are working with. OSHA’s Hazard Communication standard requires employers to provide information and training for workers on hazardous materials in the workplace.

Welding surfaces should be cleaned of any coating that could potentially create toxic exposure, such as solvent residue and paint.

Workers should position themselves to avoid breathing welding fume and gases. For example, workers should stay upwind when welding in open or outdoor environments. General ventilation, the natural or forced movement of fresh air, can reduce fume and gas levels in the work area. Welding outdoors or in open work spaces does not guarantee adequate ventilation. In work areas without ventilation and exhaust systems, welders should use natural drafts along with proper positioning to keep fume and gases away from themselves and other workers. 


• Local exhaust ventilation systems can be used to remove fume and gases from the welder’s breathing zone. Keep fume hoods, fume extractor guns and vacuum nozzles close to the plume source to remove the maximum amount of fume and gases. Portable or flexible exhaust systems can be positioned so that fume and gases are drawn away from the welder. Keep exhaust ports away from other workers.

• Consider substituting a lower fume-generating or less toxic welding type or consumable.

• Do not weld in confined spaces without ventilation. Refer to applicable OSHA regulations (see list below).

• Respiratory protection may be required if work practices and ventilation do not reduce exposures to safe levels.


Some OSHA standards applicable to welding:

• Welding, Cutting & Brazing—29 CFR 1910 Subpart Q

• Welding & Cutting—29 CFR 1926 Subpart J

• Welding, Cutting & Heating—29 CFR 1915 Subpart D

• Permit-required confined spaces—29 CFR 1910.146

• Confined & Enclosed Spaces & Other Dangerous Atmospheres in Shipyard 

Employment—29 CFR 1915 Subpart B

• Hazard Communication—29 CFR 1910.1200

• Respiratory Protection—29 CFR 1910.134

• Air Contaminants—29 CFR 1910.1000 (general industry), 29 CFR 1915.1000 (shipyards), 29 CFR 1926.55 (construction)


More Information

For more information on hexavalent chromium exposure, visit OSHA’s website at www.osha.gov.