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Excess Flow Valves diagram
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What is an Excess Flow Valve?

An Excess Flow Valve (EFV) is a safety device designed to automatically limit the flow of natural gas when the flow of gas through the device exceeds a predetermined level. Most residential and small commercial customers are eligible to have an EFV installed if their gas system operates at a continuous pressure of 10 pounds per square inch (psig) and meets other certain operating conditions. You may request Corpus Christi Gas install an (EFV) on the gas line to your property by calling the Department at 361-885-6942 during normal business hours.


What are the potential benefits of EFVs?

EFVs are mechanical shut-off devices that can be installed in the gas pipe running to the gas meter at your property (the “service line”). An EFV is designed to stop the flow of gas if the service line is broken, for example, by an excavation accident. Stopping the flow of gas from a broken service line significantly reduces the risk of natural gas fire, explosion, personal injury and/or property damage.


What will an EFV not do?

An EFV is not designed to close if a leak occurs beyond the gas meter (on house piping or appliances). The EFVs may not close if the leak on the service line is small.

Note: If you add additional gas appliances, for example, a pool heater, emergency generator, etc., the additional gas flow may cause the EFV to close.


How can I get one installed and what will it cost?

If you choose to request the installation of an EFV, you may be responsible for paying the installation cost. The average cost is typically between $600 to $2,500 but the actual costs will depend on the difficulty of the installation. Corpus Christi Gas informs you of the actual cost before you make the final decision. If you notify Corpus Christi Gas that you want an EFV, a representative will contact you to set up a mutually agreeable date to install an EFV on your service line.

Note: EFVs cannot be installed on service lines with gas loads exceeding 1,000 SCFH, low pressure or other factors. If you request an EFV but your service line cannot accommodate an EFV, a representative will let you know.


What if the EFV needs to be serviced or replaced in the future?

EFV replacement or service may be necessary if you add additional gas appliances, such as a pool heater or emergency generator that exceeds the capacity of the EFV. The EFV replacement may also be necessary if the EFV malfunctions. If it becomes necessary to replace the EFV on your service line, Corpus Christi Gas will replace the EFV at no charge to you.