Earthquake Valves
How They Work

Pacific Seismic/California Valves are earthquake actuated gas shut-off valves. They are intended to close in the event of an earthquake thus preventing gas from flowing into a structure where damage may have occurred. The California valve minimizes the potential of a fire or explosion due to the release of natural gas into a home or structure from existing gas lines.

PSP’s valves do not use any source of internal or external electrical power. These valves operate strictly by motion caused by an earthquake and are designed to remain closed until manually reset. These valves are mounted in the gas lines that are attached to the gas meters outside of the home or structure. PSP’s valves do not replace the manual shut-off valves provided in the existing gas service lines.

Our valves consist of a unique arrangement that swings closed when the acceleration-sensitive triggering mechanism is activated by a sudden motion, such as an earthquake. The trip mechanism consists of a steel ball resting on a tapered cup-shaped support. The horizontal motion of an earthquake causes the ball to move from the center of the support. This allows the ball’s mass to act upon the moveable pipe of the trip mechanism, activating the valve and initiating closure. Springs assist the valve-flapper to close and gas pressure assists in holding the valve disc in the closed position. The trip mechanism is factory set and sealed. A viewing port is built into the valve so that the Open or Closed indicator can be seen. This permits easy determination of the trip mechanism’s status.

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