Flow Sensor Valves: Patented

Flow sensor valves (FSV) are normally-open valves that snap closed when the factory preset flowrate is exceeded. Our FSV is insensitive to acceleration forces and may be used in any physical orientation. System vacuum level has no effect on the FSV setpoint. However, higher system vacuum levels will cause greater flowrates through a porous work piece.

Flow Sensor Valves eliminate the problem of vacuum loss thru non-working standard cups or thru valved cups overhanging the work piece edge. These are especially useful where work piece size and orientation will vary. For maximum effectiveness, each suction cup in the system should be equipped with a Flow Sensor Valve.

Flow Sensor Valves may be manifolded or located in-line rather than at the suction cup. Piping integrity is important since the FSV will sense a fitting leak as easily as leakage at a suction cup. Wherever installed, a suitable filter must be used upstream of the FSV. When used with EDCO fittings, a filter screen nests inside the fitting bore.

The optimum flowrate setpoint is best determined by testing the porosity of sample work pieces with a flowmeter using the same suction cup size and style as will be used in the actual system. Porosity of items such as corrugated board can vary greatly from lot to lot so it is important to find the most porous part to be handled by the system.

A factor of safety must be added to the highest porosity test value to allow for variations in work piece porosity, system vacuum level, increased leakage due to wear and other factors. For porous work pieces such as paper and corrugated cases, the factor of safety probably should be in the 50% range. For non-porous work pieces such as plastic or metal, the factor of safety may be reduced.

It is necessary to size the vacuum pump to have enough capacity to close all Flow Sensor Valves where cups are not sealed against a work piece plus the total “porosity” flow through the sealed cups. EDCO air powered multi-stage vacuum pumps are ideally suited since they produce large vacuum flowrates at low vacuum levels (0-10 in-Hg) and can provide the flow necessary to close a large number of Flow Sensor Valves.

When used with large bellows-style suction cups, the cup should be pressed against the work piece to collapse the bellows before turning on the vacuum. This prevents accidentally activating the FSV by the high instantaneous flowrate caused by the bellows collapsing under vacuum.

The FSV will automatically reset when the vacuum is turned off for a short period of time. If desired, a pressure pulse can be used to back flow the FSV and clean off the inlet filter. This blow-off pulse will reset the FSV and will quickly release the work piece.

The FSVM version includes a monitor port where a vacuum sensor can be used to monitor whether the FSV is open or closed.

The FSV 12 is a larger ½” NPT version that is for use with larger suction cups but is functionally the same as FSV 18.

The FSV 10 is for use with 15mm and smaller suction cups but is functionally the same as an FSV 18.

How to Order:
FSV 18 + FLOWRATE (SCFM x 10) + FITTING SIZE

Examples:
FSV 18- 9-50 is a standard FSV that is set to close when flowrate exceeds 0.9 SCFM and includes a size 50 cup fitting and filter screen.

FSV-6-18M is a FSV set to close when flowrate exceeds 0.6 SCFM and includes a 1/8” NPT male fitting and filter screen for inline mounting.

AVAILABLE FLOWRATE SETPOINTS:

FSV 10 = 0.1 to 0.6 scfm in 0.1 increments.
FSV 12 = 0.5 to 6.0 scfm in 0.1 increments.
FSV 18 = 0.3 to 2.3 scfm in 0.1 increments.