Fisnar VD520 Diaphragm Dispensing Valve for Adhesives, CAs, Inks and Low to Medium Viscosity Liquids

About VD520 Diaphragm Dispensing Valve

The Fisnar VD520 Diaphragm Dispensing Valve is a pneumatically activated dispensing valve which provides accurate, repeatable application of low- to medium-viscosity fluids, using an inert diaphragm to isolate the wetted path from the actuator for clean, drip-free application of materials such as cyanoacrylate adhesives, UV adhesives, and solvents.

In the VD520 design, the diaphragm isolates the wetted fluid body from the piston, air cylinder and moving parts, giving a seal-free fluid path that minimises contact between reactive adhesives and materials, and metal components.

This makes diaphragm valves particularly well suited to low to medium viscosity, fast-reacting, or easily catalysed materials such as cyanoacrylate adhesives and anaerobic adhesives, where metal contact or complex internal cavities could trigger curing or trap material. The diaphragm approach prioritises short fluid paths, chemical isolation, low internal dead volume, and clean, drip-free shut-off, especially for sensitive liquid chemistries.

Fluid flow is finely regulated through the valve and can be further optimised using the stroke adjustment knob, allowing for consistent and repeatable performance.

• Fisnar VD520-PT: PTFE diaphragm and fluid path – this is our recommended valve for dispensing cyanoacrylate and anaerobic adhesives.
• Fisnar VD520-SS: UHMW-PE diaphragm and stainless steel fluid path –  ideal for dispensing reagents, paints, UV adhesives, and other volatile substances.

We recommend using the Fisnar VC300 Two-Way Dispensing Valve Controller to control pneumatic dispensing valves. We will help you specify and purchase a complete system based around the Fisnar VD520, including automation.

Our article Better control for reactive and difficult-to-dispense fluids and liquids discusses how the Fisnar VD520 Diaphragm Dispensing Valve can be built into an industrial dispensing system.

Features & Benefits

• Versatile compatibility with a wide range of low to medium viscosity materials including acids, adhesives, UV adhesives, solvents, alcohols, cyanoacrylate adhesives, reagents, inks, and lubricants
• Precise stroke adjustment for accurate flow control
• Smooth, short flow path reduces turbulence and bubbles
• Separated wetted parts for clean, reliable operation and servicing
• Fast shutoff prevents drips and waste
• High-speed performance up to 500 shots/minute
• Compact, durable, lightweight and suitable for machine integration

Applications

Fisnar VD520-PT and VD520-SS dispensing valves are suitable for the application of:

• Cyanoacrylate adhesives
• Anaerobic adhesives
• Reagents
• UV/light-curing adhesives
• Paints
• Inks
• Solvents
• Electrolytes
• Alcohols
• Volatile materials

Specifications

Operation

The Fisnar VD520 Diaphragm Dispensing Valve is a normally closed, pneumatically actuated valve. A flexible diaphragm forms the sealing surface between the fluid inlet and outlet.

• Material is fed to the valve under controlled fluid pressure from a reservoir.
• When a pulse of air pressure, typically 70 to 100 psi, is applied to the air inlet of the valve (1), it drives an internal piston (2) upwards.
• This lifts the diaphragm (3) away from its seat and opens an unrestricted flow path (4), allowing liquid to pass through and out of the dispense tip.
• When the air signal is removed, a spring (5) forces the piston back down, pressing the diaphragm firmly onto its seat for an immediate, positive shut-off of flow.
• Shot size is controlled by a combination of valve open time, fluid pressure, tip size, and the mechanical stroke adjustment knob (6), which limits how far the diaphragm can retract. A set-screw (7) locks the stroke adjustment.

All Downloads

Filename	Size	Download
FISNAR VD520-SS Operating Manual	1.54MB
FISNAR VD520-PT Operating Manual	1.41MB
Improving Industrial Dispensing with Pneumatic Dispensing Valves	0.37MB

Ordering Information

01865 842842	orders@intertronics.co.uk