The model 910 is a high flow, pneumatically operated, pinch valve that features the ability to use large diameter (up to 1/2" outside diameter, 3/8" inside diameter) plastic (Teflon, Polyethylene, or Polypropylene etc.), or elastomeric (Urethane, Silicone or vinyl etc.) pinch tubes. It features adjustable, lockable controls to set both the flow rate (the amount the tube opens) and the amount of tube closure (which insures the accuracy and repeatability of operation and greatly extends tube life). A variety of nozzles and nozzle adapters are available. The 910 can be used as a dispense/filling valve or as an inline two way (on-off) valve with adjustable flow. A Tridak valve controller or customer supplied controls can be used to operate the valve.

Features of the 910 valve are:
• Tubes can be plastic, (Teflon, etc.), or elastomeric (Urethane, etc)
• Tubes can be up to 1/2" outside diameter
• Adjustable, lockable flow control and over pinch adjustment
• Pinch automatically compensates for tubing wall thickness variations
• Disposable wetted parts allowing quick change out of materials
• Positive shutoff
• Air operated
• High speed operation

The 910S is a variation of the 910 valve. It provides the advantage of quick change out of the supply tubing without having to readjust the Pinch Force and Flow Control features. Tube sizes can be up to 7/8” OD and the pinch automatically compensates for tubing wall thickness variations.

The 910 weighs 3.3 lbs. while the 910S is 4.25 lbs.

The liquid pressure is tubing dependent with 100 PSI being the typical maximum and the maximum flow rate for any tubing is dependent on the amount of permanent deformation a tube takes after it is pinched to closure. For tube materials such as natural rubber and silicon that do not tend to set very little, flow rate is the equivalent of the full bore tube.

Pinch Tubing
We stock a variety of tubing types in several diameters suitable for use in the 910 (typically ). Typical materials for pinch tubing are urethane, polyethylene, Teflon, silicone, and vinyl in diameters of 1/4" O.D., 3/8" O.D., 1/2"O.D. Most have a life in the 1 to 10 million cycle range and certain materials such as natural rubber and silicone may have a life of billions of cycles. With the stiffer plastic tubes the wall thickness of the tubing is important for proper valve operation.

Operational considerations

Closed - When the 4-way, spring returned valve is in its off (un-actuated) position, the pinching surface of the air operated piston prevents flow by collapsing the tube. The pinch stop adjusting mechanism limits the amount of pinch and therefore limits the stress on the tube. This control greatly extends tubing life and insures shot to shot repeatability. The 910S differs only in that the tube closure is by spring with fail safe mode active when the air is off.

Open - When the valve is activated, the air moves the piston back to the adjustable stop. This controls the amount the tube opens. This in turn, controls the rate of flow through the tube. These actions, combined with nozzle size (if a nozzle is used), fluid pressure, and the amount of time the it is open, governs the amount of fluid dispensed.

Tube Replacement (910S) - To achieve this is a simple procedure. The valve body is first separated. To do this, the handle is rotated and the clamp is swung to the side. This allows the valve body to be separated form the mounting base. Place new tubing in the mounting base and reinstall the valve body. Swing the clamp back over the valve body and lock in place by rotating the handle to the lock position.

The 910/S valves work in conjunction with the 345.0.0 controller.

© Drawbridge Leaders, Inc. 2006-9