Earthquake Shut-off Valves

Watching the dramatic footage from Japan after the earthquake and tsunami, it reminded me that fires are caused by exploding gas lines and I still haven’t got around to installing a gas shut-off valve for the house. These valves can be triggered automatically either by an excess flow of gas or seismic activity. In the photo, if I had a red shut-off valve, it would appear on the right-hand side.

The shut-off valves have to go on the homeowner (right-hand) side of the meter and the meter itself is owned by the Gas Company. They won’t install shut-off valves themselves and they won’t recommend any contractors. You need to find someone who is certified by the State of California, meaning a licensed plumbing contractor.

There is a manual switch, of course. You can find it on the left-hand side of the meter and it runs the way the gas is flowing (it’s not visible in the photo – it’s off to the left). To turn the switch off manually, to stop the gas from flowing, you twist it to right angles with a wrench. But if an earthquake strikes you may not be home, hence the value of an automatic shut-off valve.

In the event that there is an earthquake and the shut-off valve activates, there may be a delay before the Gas Company can turn the service back on, but you should not do it yourself. It also requires that all appliance pilots be relit.

So - are you prepared for the next big earthquake? Further reading here.

Update: in April I installed a shut-off valve. It was gray though, not red. Basic principle is that if there is a mild quake and it rocks the ball off its perch to block the gas line, I don’t have to call anyone. There is a lever I push to restore the ball to its original position and the gas begins flowing again.