What Was Doent to Prevent the Ohio Gas Explosion to Happen Again ?
The gas explosion that rocked a New York City neighborhood concluding month is the latest warning that leaky urban pipelines are badly in demand of an overhaul. The National Transportation and Condom Board'south (NTSB) investigation of the East Harlem blast and fire found small-scale gas leaks below the pavement at the site of the March 12 detonation (pdf) that destroyed two buildings, killing eight people and injuring dozens.
Investigators have sent faulty sections of 127-year-old cast-fe pipage likewise every bit a section of 20-centimeter (viii-inch) plastic pipe installed in 2011 to the NTSB lab in Washington, D.C., for farther testing. There they will effort to make up one's mind the roles played in the tragedy by iron alloy degradation, pipeline age and articulation design connecting the dissimilar pipes.
Leaks and explosions involving natural gas transmission and distribution pipelines in the U.South. crusade an average of 17 fatalities, 68 injuries and $133 1000000 in property harm annually, co-ordinate to a study released earlier this year. In the January outcome of Environmental Science & Technology the researchers described their efforts mapping nearly 5,900 natural gas leaks of varying severity beyond 1,500 road miles of Washington, D.C. To learn more nearly the state of the gas pipelines running through several major U.S. cities—in detail those serving New York City—Scientific American interviewed Robert Jackson, professor of environmental sciences at Stanford and Duke universities and the study'south lead author.
[An edited transcript of the interview follows.]
When did U.S. cities brainstorm installing natural gas pipelines, and why?
Cities first began installing pipelines to carry gas to streetlights about 200 years ago. The large era of pipeline construction began a fiddling later, starting after the Civil War and ramping up in the get-go half of the 20th century.
What is the source of New York City'south natural gas?
New York gets its natural gas from pipelines as far as Texas and Louisiana. The new pipeline built by Texas-based Spectra Energy and opened on [November 1, 2013], runs under the Hudson River from New Bailiwick of jersey to Greenwich Village. It brings gas from the Marcellus Shale and other areas to the city.
Given the size and age of the infrastructure and the number of people served, how would yous characterize NYC's safety tape with regard to gas leaks?
The proficient news is that pipeline safety in the U.S. is ameliorate today than it was 20 years ago, a credit to companies doing their jobs. The bad news is that pipeline leaks and incidents notwithstanding kill a dozen or more people a year and cost consumers $2 billion yearly from leaky pipes. New York City has more leaks per mile than average, simply it has older pipes than boilerplate.
What materials were the original pipes made from, and why were those materials used?
Until about 1950 virtually of the natural gas pipelines in New York and elsewhere were made of molded cast-fe. Information technology was land-of-the-fine art at the time.
Does the gas itself wear out or damage the pipes or is that primarily the upshot of cold, moisture conditions (plus common salt from snowstorms) underground?
Corrosion inside the pipes from h2o and other impurities is a bigger problem upstream near well pads than downstream near consumers. The Pipeline and Hazardous Materials Condom Administration (PHMSA) estimates that about 1 in 7 pipeline incidents nationally is caused past internal corrosion. In a city like New York external factors including frost heaving, cracking, corrosion from water and salt, and leaking pipe joints are a bigger issue.
What materials are used to make mod gas pipes, and why is this material used?
Most new gas pipelines today are plastic. Protected steel pipes are oftentimes used for college force per unit area, longer distance transmission lines. Plastic and protected steel both corrode more slowly than cast-atomic number 26 and are less brittle.
What is the biggest challenge to NYC upgrading its existing gas pipe infrastructure?
Like the old adage about real manor and location, it's money, coin, money. A mile of new pipe in a metropolis like New York can cost a million dollars—the reason companies try to repair pipes starting time. Sometimes they can also "sleeve" a pipe, inserting a new smaller plastic line within an old pipe so they don't have to dig it up. That's much cheaper.
What is the most effective way to cut downwardly on natural gas leaks in NYC and other large cities?
Repair and supervene upon the unprotected steel and cast-iron pipes, some of which are more than a century erstwhile. They corrode, crevice and, once in a while, leak similar a sieve. State public utilities commissions are important levers because they cap the amount of money companies can recover for repairs. In that location are federal agencies relevant to the discussion, though. FERC [the Federal Energy Regulatory Commission] regulates interstate transmission of natural gas—plus oil and electricity—from the standpoint of commerce. PHMSA, a role of the Department of Transportation, regulates pipeline prophylactic. The distribution companies, of course, are responsible for actual pipeline safety operations.
New York Land'southward Public Service Committee has ordered New York City'due south utility Con Edison to replace 70 miles of pipage per yr past 2016. Could yous put this number in perspective?
Recently I did an analysis looking at pipeline replacement rates for different cities between 2004 and 2013. Between 2004 and 2012 Con Ed replaced about 15 miles of cast-iron pipes a year—not much compared to the 1,400 miles they had at the start. Between 2012 and 2013 they replaced 110 miles, substantially more. In full, Con Ed was on rail to supplant its cast-iron pipes in most 40 years. Duke Energy of Ohio, which serves Cincinnati, had the best track record in the land, replacing 80 percent of its cast-iron pipes through an aggressive program canonical by the Public Utility Commission of Ohio in 2001. In contrast, Baltimore Gas and Electrical was on rail to supervene upon its cast-iron pipes in 140 years, by around the year 2150. They need less tortoise and more hare.
What, if annihilation, makes NYC's natural gas pipage system significantly different from systems in other large U.S. cities?
New York'southward pipeline network is pretty like to networks in other older cities such equally Boston and Washington, D.C. In both of those cities our team has mapped thousands of natural gas leaks cake past cake.
When did utility companies brainstorm using the compound mercaptan to add together olfactory property to their gas networks equally a rubber measure?
A natural gas explosion in 1937 killed 300 students and teachers at an elementary schoolhouse in New London, Texas. This tragedy prompted companies to first adding an "odorant" into natural gas, which is odorless.
Are there any skilful alternatives to natural gas utilize in a urban center?
There are bad alternatives to natural gas use in the city. Burning low-grade heating oil is probably the worst, giving off more than soot than all the cars and trucks there combined. Information technology'due south one of the reasons there are 300,000 kids with asthma in New York Metropolis. For power plants, burning natural gas is cleaner than coal and dirtier than air current, solar and hydropower.
Source: https://www.scientificamerican.com/article/how-can-cities-protect-themselves-against-gas-explosions/
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