Do You Have an Earthquake Valve?

Since 2000, all newly constructed buildings in California must install earthquake shut-off valves. Local law enforcement agencies enforce them when issuing building permits. Despite the fact that earthquake shut-off valves could save your life, however, many Californians don’t know what they are or haven’t installed them in their older homes. At HP Mechanical, we have many customers in Santa Rosa, CA and throughout the North Bay that often ask us about the importance of earthquake valves and how they work.

Is your home protected in the event of a major earthquake? Every building that’s connected to gas in California should have an earthquake shut-off valve. That means every Californian should understand how an earthquake gas shut off valve works. Here are the important things to know, including how to update your home and be prepared if an earthquake does rattle your gas line.

What is an Earthquake Shut-off Valve?

Earthquake shut-off valves are specialized valves that attach to your building’s gas meter. In the event of an emergency, these valves automatically close, cutting off gas from flowing into your line. There are two common varieties of earthquake shut-off valves:

Seismic Natural Gas Shut-off Valve: These valves trigger when they detect an earthquake of magnitude 5.1 or higher.

Excess-flow Valve: These valves trigger when they sense a gas leak or overpressure surge somewhere in your gas line.

How Do Earthquake Shut-off Valves Work?

They’re surprisingly simple! The valve is installed onto your gas meter where the meter connects to your home’s gas pipes. The two types of shut-off valves detailed here are designed to react to different things, so they both work differently.

The seismic gas shut-off valve reacts to shaking. A metal ball is installed inside your gas pipe directly above the main line the gas uses to get into your house. When the pipe begins to shake with a magnitude of 5.1 or greater, that metal ball dislodges from a suspension ring and blocks the gas line. The metal ball’s blockage prevents gas from moving further down the line and into your house.

The excess-flow valve is a more conventional valve than the seismic gas shut-off valve. The distinctive difference is that the excess-flow valve is designed to look for leaks or high-pressure in your gas line, not seismic activity. This valve includes an excessive flow sensor. This sensor fits into the internal mechanism of the valve itself. When it senses that the natural gas that passes by it is flowing too quickly, either as the result of excessive pressure or via a leak, it tells the valve to clamp down. This prevents further pressure build-up or more gas from escaping through the leak.

Which Valve Works Best?

These two valves are separate mechanisms, and each requires separate installation. Both have distinct advantages and disadvantages:
The seismic shut-off valve is very good at preventing gas from getting out through leaks caused by earthquakes, but it cannot detect how those leaks were made.

The excess-flow valve reacts to more than the seismic shut-off, but it’s best at responding to big problems. The excess-flow might not always find small leaks that only cause gas to flow a little faster than usual.

Either valve can be installed to your natural gas line without the other, but for maximum safety, HP Mechanical recommends you get both installed.

Why Are Earthquake Shut-off Valves Important?

Powerful earthquakes can instantly break gas pipes, leading to extremely dangerous gas leaks. Gas leaks are particularly dangerous inside structures, where the gas gets trapped and builds up. Trapped gas is highly flammable and poisonous. On top of triggering the gas leak itself, earthquakes also often create situations where gas can easily ignite. If earthquakes start a fire and that fire contacts gas inside your home, it could trigger an explosion.

The worst damage often happens because of gas leaks after earthquakes. During the Great San Francisco Earthquake of 1906, fires caused 90% of the damage to the city. Ruptured gas lines sparked 30 fires that destroyed 490 city blocks.

Earthquake valves protect your home from earthquake-related gas leaks and the fires they cause. When an earthquake hits near you, you may not have the time or presence of mind to worry about your home’s gas line. A safety valve gives you the peace of mind to focus on your family’s wellbeing without distraction. After an earthquake, you simply reset the valve after checking to make sure your gas lines aren’t damaged. If the lines were damaged, the valve ensures that gas doesn’t enter your home until they’re fixed.

About HP Mechanical

For many years, HP Mechanical has proudly provided comfort to thousands of homes and light commercial businesses across the Santa Rosa/Windsor area and throughout Sonoma County. We are an honest, loyal company who takes pride in our work. We take care of our customers as if they were family. Referrals are where 90% of our business comes from, so the relationships we build along the way mean a lot to our small business. The one constant with everything involves working and helping people, by striving to provide the best service available at a reasonable cost. We take personal responsibility to make sure comfort and quality meets accountability & affordability, with exceptional customer service every time!

Sources: Santa Rosa Press Democrat and AOL.com