Type N551 Snappy Joe Emergency Shutoff Valves are intended for in-line use on LP-Gas or Anhydrous Ammonia (NH3) service.
The valves may be installed on both ends of transfer hoses where the hose connects the bulk plant piping to the bobtail, transport, or tank car. They provide a quick way of automatically shutting off gas flow in the event of a hose rupture. A fusible element in the latch melts if the temperature reaches 212°F / 100°C, allowing the valve to self-close.