Auto Stop/Excess Flow Valves

Flo-Fuse®

The Marotta Flo-Fuse is a normally open excess flow shut-off valve, held open mechanically during normal rated flow conditions. It will tolerate overloads up to 100% above normal flow settings. Designs are available with very close tolerance between normal and shut-off flows. Such overloads may be experienced in a system due to operation of regulator valves, actuators, etc.

A built-in dashpot feature absorbs transient pressure surges of substantially greater magnitude. In the event of excessive flow, the Flo-Fuse excess flow control valve closes instantly – – stopping flow and/or escaping line fluid. The valve remains closed, effectively isolating the failure until the damage is repaired and the Flo-Fuse is reset. See resetting under ‘Options’ for various methods that can be applied to fit your application.

Closes Rapidly

Closes rapidly in the event of a downstream line failure; responds to sudden or sustained flow surge.  Flo-Fuse is engineered for liquid or gas systems in which a ruptured or otherwise failed line would be a major safety or environmental concern.

Provides Basic Safety

Flo-Fuse provides basic safety for hydraulic and pneumatic systems by isolating a failure in a manner similar to the way a circuit breaker protects an electrical installation.

Flow-Sensitive Device

Just as the current sensitive breaker actuates from excessive current, Flo-Fuse shuts off from excessive flow – such as would occur from line breakage, component failure, or human error.

Materials

Varied material selection, meeting the needs of almost every liquid or gas service – whether inert, corrosive, radioactive, toxic, noxious or inflammable

Operation

Normally open valve, held open mechanically during normal rated flow conditions.  It will tolerate overloads up to 100% above normal flow settings.  Designs are available with very close tolerance between normal and shut-off flows.  Such overloads may be experienced in a system due to operation of regulator valves, actuators, etc.  A built-in dashpot feature absorbs transient pressure surges of substantially greater magnitude.  In the event of excessive flow, Flo-Fuse closes instantly, stopping the flow and/or escaping line fluid.  The valve remains closed, effectively isolating the failure until the damage is repaired and the Flo-Fuse is reset

Position Indication

Visual position indication, either local or remote, can be provided as an option for Marotta Flo-Fuses.  The selection of the type of position indication will depend upon the fluid, the environment, the current requirements and/or the Flo-Fuse location.

Visual Indication

Visual indication can only be used in installations where the valve can be easily inspected.  Since seals are required, this type of position indicator is limited by the compatibility of the seals within the line media

Reset

Flo-Fuse remains closed after a system malfunction until it is reset.  Upon completion of the system repair, use one of the following methods to re-establish normal system operation:  manual reset; automatic reset (bypass bleed orifice); remotely actuated solenoid. Reset results from the gradual repressurization of the downstream portion of the system.  When the pressure is equalized on both sides of the Flo-Fuse, the poppet return spring re-positions the valve to the normally open position.

Adjustable Shut-Off Flow

In systems where the flow rates are difficult to determine, or where the shut-off flow rate band is narrow, adjustable Flo-Fuses provide this added versatility.