A small device near a gas meter can look like a simple safety purchase. In reality, earthquake-actuated and excess-flow gas shutoff valves have different triggers, installation positions and rules. The serving utility may own some piping and prohibit customer work on it.
This page is a pre-quote decision aid. If gas is suspected to be escaping now, leave the area and contact emergency services and the serving utility from a safe place; do not remain to inspect or operate a purchase candidate. For other home gas emergency decisions use what to do if you smell gas.
Compare the valve’s actual trigger
| Question | Seismic/earthquake valve | Excess-flow device |
|---|---|---|
| Intended trigger | Qualifying local shaking | Certain unusually high flow rates from damaged piping |
| Can it detect every gas leak? | No | No |
| Is it a gas detector? | No | No |
| Location and ownership | Must follow utility, local and product rules | Different utility-side/customer-side options and restrictions |
| After activation | Qualified inspection and restoration may be needed | Utility and device-specific procedures govern |
| Shopping proof | Exact certification, approved size and qualified installer | Exact system and utility compatibility |
PG&E’s current guidance describes both kinds of devices, requires certified valves and licensed plumbing work on its customer-owned house line, and warns against altering utility equipment. SoCalGas independently describes installation and utility-side limits; service rules are not interchangeable across suppliers.
Four questions before an installation quote
- Which utility serves the property? A city ordinance, new construction, renovation or insurer may trigger different requirements.
- Who owns the exact pipe section? Ask the utility and licensed installer to identify the allowed house-line location. Do not open meter cabinets or operate utility controls.
- Is the exact model approved for the purpose? Ask for California certification if required, pipe size, gas flow compatibility and installation manual.
- Who can restore service? A closed gas service valve can require utility or qualified professional inspection; never assume it is safe to restart the appliances yourself.
The Earthquake Country Alliance gas-safety guide cautions that automatic shutoffs can also delay service restoration. Installing a valve does not eliminate the need for working CO alarms, properly maintained appliances and a household evacuation plan.
Do not shut off gas just because the ground shook
PG&E advises shutoff only when gas is smelled or heard escaping, a line is visibly broken, or a leak is suspected. If you encounter those conditions, evacuate and call from a safe location rather than testing a valve or trying to prove the source. Follow your actual serving utility; do not switch electrical devices or create sparks near a suspected leak.
Gas valve quote check card
| Question | Evidence from utility or installer |
|---|---|
| Serving utility and current local requirements | |
| Device type and exact model/certification | |
| House-line ownership and permitted location | |
| Licensed installation, permit and inspection | |
| Operating/tripping limitations | |
| Post-trip inspection and service restoration contact |
The next action is to ask the serving utility and a qualified installer for a scope in writing, not to buy a valve based on a product-star rating.