For decades, schedule 40 black iron pipe was the default choice for piping gas to furnaces and water heaters. But in the United States, there are about 24 people killed every year in fires caused by leaks or breaks in the natural gas or propane systems. Many deaths are caused by leaking gas that lead to explosions. That is why an alternative to black iron pipe was developed—corrugated stainless steel tubing (CSST). First developed in Japan to solve the dangers of broken rigid gas piping in an earthquake, and then brought to the United States by the American Gas Association (AGA) and the Gas Research Institute (GRI) in the United States as an alternative gas piping solution, CSST was developed to eliminate the difficulties and dangers of rigid gas piping.
Rigid pipe presents a variety of problems:
- Rigid pipe breaks in earthquakes and other natural disasters
- Multiple joints frequently leak
- Pipe dope deteriorates over time and leaks when exposed to lightning strikes
- Black iron pipe is not listed to any national standards for gas piping. CSST piping can withstand the same forces of nature—earthquakes, lightning, tornados—that make black iron pipe crack
- Most rigid steel pipe is made in Asia—with no quality control
The rigid pipe joints are a well recognized cause of gas leaks and fires. The National Fire Protection Association (NFPA) publishes the Guide for Fire and Explosion Investigations (NFPA 921), and notes in Chapter 9 that joints and fittings in rigid pipe systems are the most common sources of gas leakages and gas fires and explosions:
- 4.1 Pipe Junctions. Improper connections between piping elements, such as inadequate threading (not enough turns for gas tightness), improper threading (cross-threading or right-hand threads merged to left-hand threads), or improper use of pipe joint compound (too much or too little) can cause gas leaks. Pipe junctions are also the most common locations that leak as a result of physical damage to fuel gas piping systems.
- 4.8 Physical Damage. Physical damage to fuel gas systems can cause leaks. Strain put on gas piping systems may manifest itself at the pipe junctions and unions. Because pipe elbows, T fittings, and couplings are more rigid and stronger than the pipes they connect, and because the threaded ends are weaker than the rest of the pipes, stress damage usually occurs in the threaded portions of the pipes immediately adjacent to the pipe fittings.
Leaking joints in a rigid pipe system can cause an accumulation of fuel gas and a resulting explosion. Alternatively, leaking gas can ignite from an open flame or pilot light or other ignition source. Below are a few incidents recorded from government investigations and news media.
Hatboro PA – 6 people dead from gas explosion caused by broken black iron pipe – caused by flooded basement.
On June 16, 2001, an explosion occurred at the Village Green Apartments complex in Hatboro, Pennsylvania. The basement in one apartment was flooded due to heavy precipitation from tropical storm Allison. A gas-fired clothes dryer located in the basement of the apartment building was displaced due to water suddenly and rapidly entering the basement. The rigid black iron pipe servicing the dryer cracked at a joint when the dryer floated away, and the crack allowed an unrestricted flow of natural gas into the basement. After a period of nearly three hours, an explosion and subsequent fire occurred, resulting in several personal injuries, and six fatalities. A re-enactment of the failure mode using CounterStrike CSST proved that it would not have cracked in those same circumstances. This is one proven example where using CounterStrike CSST would have saved lives.
Atlantic IA – 2 people dead from gas explosion – break
In February 2015, a husband and wife were killed in a gas explosion. The cause was a leak in the rigid black iron pipe in the basement that the wife used to hand her laundry. The strain and the stress of the load on the threaded connection over the years caused it to bend and crack, allowing natural gas to leak into the basement.
On Tuesday, June 11, 2013 at approximately 8: 16 a.m. there was an explosion and fire at the residence of Ms. Lena Knight, 185 N. FM 1486 Dobbins Texas, Montgomery County. One infant and two women were in the house at the time of the incident. All three victims were transported by medical helicopter to the hospital in Galveston, Texas. Both women would later die from their injuries. The residence was totally destroyed from the explosion. The explosion was caused by a leak in the vertical section of black iron piping that had come up through the kitchen floor and connected to the cook stove was corroded and broken.
On September 26, 2011, a natural gas explosion and fire destroyed a house located at 12312 5th Avenue N.E., in the Pinehurst neighborhood of Seattle, Washington. The incident involved a black iron distribution pipe owned by the local utility. The homeowners were inside the house at the time of the explosion. One person sustained serious physical injuries from the incident. She was treated for burns over an estimated 40% of her body. The other occupant received first and second degree bums to his upper torso and face. The cause of the explosion was natural gas leaking from the pipe located near the foundation of the house. The gas leaked through a one-eighth inch diameter hole in the pipe, which was located where the gas pipe crossed over the sewer pipe that served the house. An electrical arc between the steel gas service pipe and the iron sewer pipe created the hole in the gas service pipe.
Plymell KS – 3 people dead from gas explosion – cause unknown
On June 28, 2014, a gas explosion destroyed a house in Plymell KS. The three occupants in the house, a mother and two teenage sons, died from their injuries in the blast. When the news media attempted to find out what caused the blast, they were surprised by what they found. Doug Jorgensen, the Iowa State Fire Marshal, said once events are determined to be an accident, his office stops its investigation. Officials ruled the explosion at the Unruh’s home an accident within 24 hours of the blast. Who is finding out where the gas leak was, what caused the leak, if odor was ever added to the gas, and if the family reported an odor? The State Fire Marshal’s Office is not responsible for keeping track of problems or patterns. So if the State Fire Marshal’s Office is not responsible for keeping track of problems or patterns, who is? – Quoted from kwch.com, “FF12: Who’s investigating deadly gas explosion?”, Aug. 6, 2014.
People who question the safety of CSST never seem to examine the alternative technology – black iron pipe. But as you can see, there are numerous injuries and deaths every year from this old antiquated technology. Every death is a tragedy, and that is why manufacturers are moving to a safer CSST design using the conductive jacketed CSST. In fact, there have been no injuries or deaths associated with Omega Flex’s world-class CSST products.
ADVANTAGES OF CSST PIPING
Twenty years ago, the American National Standards Institute published the first CSST product standard—ANSI LC 1. Since then, over 1 billion feet of CSST have been installed in over six million homes in North America.
Financial and Human Costs
Rigid pipe has a number of drawbacks—it is inflexible and it has multiple joints. Working with rigid pipe also involves major handling and material hassles. First, there is the capital cost for equipment and tools required for cutting, threading, and deburring rigid pipe. Then there is the hassle of storing and disposing cutting oil in compliance with environmental regulations.
Adding to these difficulties is the impact on human resources. Workers lugging 21-foot sections of schedule 40 pipe will lead to higher workers’ compensation claims. Time is lost training employees on the old practices of rigid pipe installation and leak checking. And finally, material is lost in scrap and rework by new trainees and old pros alike. In contrast, CSST piping removes these material and human-resource hassles. A 250-foot reel of ½” CSST weighs only 40 pounds. CSST needs only two connections—at the beginning and the end—with fittings that are easy to assemble with typical hand tools and that seal leak-tight each and every time.
Advantages of CSST Piping
Twenty years ago, the American National Standards Institute published the first CSST product standard—ANSI LC 1. Since then, over 1 billion feet of CSST have been installed in over five million homes in North America.