Earthquake Shut Off Valve Seismic Gas Valve

Earthquake valve or seismic gas valve is known as preventative automatic unit to turn off gas input to building in case of an earthquake.

At City Plumbing  we specialize in the installation of earthquake shut off valves.  In the San Jose, CA region earthquake shut off valves are a necessity.  Earthquake shut off valve or seismic valve is an automatic safety feature that allows the shut off of low pressure gas flow to a home or business during the earthquake.  Earthquake valves can also prevent further harm or damage to the structure if there is damage to the pipe or if it is broken. These are applicable both to utility supplied natural gas and to gaseous liquefied petroleum gas (LPG).

seismic valve

Generally speaking, the earthquake shut off valve is installed on the property gas meter.  The purpose of these emergency shut off valves is to immediately stop the flow of natural gas in case a earthquake strikes your San Jose area home or business.

Emergency shut off valves can prevent serious damage if a gas line breaks causing a major explosion.  It is recommended that all homeowners and commercial property owners shut off their properties gas supply immediately after an earthquake, especially if you smell gas.

seismic valve

After the quake has stopped and you have determined that it is safe to do so, follow the manufacturer’s instructions for restoring your gas service. You will need to make sure no gas leaks exist and re-light your pilot lights. You must ensure that your appliances are safe before operating them. The Gas Company charges a fee to reset valves and re-light pilot lights when your seismic shut-off valve has closed due to a non-seismic occurrence.

The Gas Company recommends that you contact a licensed, qualified professional or The Gas Company to reset the seismic valve, and to verify that no gas leaks exist, to ensure that all of your gas appliances are safe before being placed back in operation and to re-light your pilot lights. Remember that following a major emergency it may take many days or even weeks before someone can come to your location.

earthquake valve


The strange little red thing on the gas pipes is an earthquake valve. It shuts off the gas automatically if there is an earthquake.

There are Two types of valve, one is sensitive to motion and the other to excessive gas flow. The most secure installations would use one of each type connected in series.

earthquake shut off valve

Excessive flow sensor: A valve is closed when the flow exceeds a certain limit appropriate to the application. This will only operate when a pipe is broken, and so may not operate if a small (yet potentially dangerous) leak is present. If activated, any faults in the piping must be first repaired.

Motion sensing caged ball: A metal ball is retained away from an orifice by sitting upon a ring. Any shaking of the mechanism will cause the ball to roll of its ledge and fall down to block the orifice. it is reset using either an external magnetic device or an internal lift mechanism. If too sensitive it may be triggered by passing vehicles on a rough road. In the case of a severe seismic event, the gas piping should be completely inspected for breaks before resetting and then “sniffed” using a gas detector device after resetting. Since all pilot lights will go out, some appliances must be properly restarted once the device is reset. The safest means is to have the gas supplier inspect the piping and relight the appliances, even though this could take quite a while in an event affecting a wide area. Such inspections and relights are typically performed without charge by the provider.

We have few tips about earthquake valves in link provided below:

How to reset earthquake valve. Earthquake valve operating. Common problems about seismic valves.

City Plumbing is a licensed plumbing contractor with certified plumbers on staff and can easily and professionally install earthquake valves (seismic valves) and emergency shut off valves.  Call today for same day service! (408) 800-3091

earthquake shutoff valve installation