Flow Sensor Valves: PATENTED

Flow Sensor Valves are normally-open valves that snap closed when the factory preset flow rate is exceeded. Our Flow Sensor Valve is insensitive to acceleration forces and may be used in any physical orientation. System vacuum level has no effect on the Flow Sensor Valve set point, however, higher system vacuuml levels will cause greater flow rates through a porous work piece.

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

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

The optimum flow rate set point is best determined by testing the porosity of a sample work piece with a flow meter using the same vacuum 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. It's 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 various factors. For porous work pieces such as paper and corrugated cases, the factor of safety should probably be in the rage of 50%. 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 flow rates at low vacuum levels (0-10 inHg) and can provide the flow necessary to close a large number of Flow Sensor Valves.

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

The Flow Sensor Valve 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 valve and clean off the inlet filter. This blow-off pulse will reset the Flow Sensor Valve 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 valve is open or closed.

The FSV-12 is a larger 1/2" NPT version that is for use with larger vacuum cups but is functionally the same as the FSV-18.

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

How To Order:

FSV18 + FLOWRATE (SCFM x 10) + FITTING SIZE

Examples:

FSV18-9-50 is a standard Flow Sensor Valve that is set to close when a flow rate exceeds 0.9 SCFM and includes a 55 mm cup fitting and filter screen.

FSV18-6-18M is a Flow Sensor Valve set to close when the flow rate exceeds 0.6 SCFM and includes a 1/8" NPT male fitting and filter screen for inline mounting.

Available Flow Rate Setpoints:

FSV-10 = 0.1 to 0.6 SCFM in 0.1 Increments
FSV-18 = 0.3 to 2.3 SCFM in 0.1 Increments
FSV-12 = 0.5 to 6.0 SCFM in 0.1 Increments

Conversion: 1 SCFM = 28.32 NI/m