CALIFORNIA (formerly known as Koso) Seismic Gas Shutoff Valves

  • Valve must be installed with gas flow in direction of "Arrow" cast into valve body.
  • Valves must be rigidly mounted, usually at or near the structure, to avoid nuisance trips. To facilitate rigid installation, we recommend the use of Unistrut-type bracket assemblies. (See diagrams)
  • Valve should be installed downstream of the gas utility's post-meter bypass "T" fitting, and sized based on properly sized customer line(s).
  • No valve shall be mounted in a gas company's meter vault without the utility's approval.
  • Note: Before cutting into any buried line, check for corrosion. If lines are severely corroded, they will not rethread properly. This could result in expensive corrective measures.
  • Pressure assessment must be made prior to valve selection and installation. Be sure to select valve that meets appropriate pipe size and pressure requirements. Typically, residences can use low-pressure valves (rated at psi). Many commercial and industrial buildings require a high-pressure valve, which is designed for operating pressures up to 60 psi.
  • Commercial installations follow the same basic procedures as residential. However, if gas-company equipment needs to be relocated, contact the utility for their recommendations.

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Preferred Installation

Plumb line and reset shaft are facing away from structure.
Note: configuration of gas pipe and directional flow of gas in relationship to valve. Most meters are installed with gas flowing from left to right.

Optional Installation

Plumb line and reset shaft are facing structure. Note directional flow of gas in relationship to valve. Be sure to leave adequate clearance (4 inches) between structure and valve, allowing access for easy valve reset.

Vault Installation

Do not install seismic valve in gas utility’s vault without the utility’s approval. Install the valve in a separate vault, as shown in diagram. When mounting valve in vault, orient the reset shaft and plumb line facing outward, to allow access for valve resetting.
The piping next to the CALIFORNIA (Koso) Valve should be braced to a concrete block in the bottom of the vault that is surrounded by gravel to allow for drainage in the event that the vault is flooded.