Pacific Seismic/California Valves are
earthquake sensitive gas shut-off valves. They are intended to close in the
event of an earthquake to prevent gas flow into a structure where earthquake
damage may have occurred. The valve reduces the potential for fire or
explosion due to the release of natural gas into a structure where gas
lines, gas fixtures, or gas appliances.
PSP's valves do not use any source of
internal or external electrical power. They are designed to remain closed
until manually reset. The valves are intended to be mounted in the gas line
upstream or downstream of the gas-line pressure regulator and gas meter
outside the structure. These valves do not replace the manual upstream
shut-off valves provided in the gas service line.
Our valve consists of a swing
check valve arrangement with an acceleration-sensitive triggering mechanism.
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 balls mass to act upon the
movable 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 sight glass is provided so that the Open or Closed
indicator can be seen, and the trip mechanism status of the valve can be