TFS Takasago Fluidic Systems

Zero-Internal-Volume Valve (Patented)

March 28, 2020

The "internal-volume" is the space between the diaphragm and the body. When the valve closes, this volume is trapped, often reducing the sensitivity of a test instrument. In the old design, the protruding valve seat is hard and prevents the TeflonTM diaphragm from flattening against the valve body.

In the Zero-Internal-Volume system, a special soft inert elastomer (perfluoroelastomer) is used for the valve seat. When the valve closes, the soft protrusion presses flat, eliminating the internal volume.

 Zero-Internal-Volume Valve takasago original

Features of Zero-Internal-Volume

Cross-contamination prevention
Faster flushing
Perfect ejection of air-bubbles
Reduction of sample or reagent volumes
The use of soft elastic valve seats also prevents particle induced leakage.

Features of Zero-Internal-Volume

The below links to the results of an investigation into the influence on analytical accuracy that the Zero-Internal-Volume structure had when incorporated into the concentrator (On-line direct concentrator) for a gas chromatograph.An improvement in analytical accuracy was observed.
Influence of the internal-volume upon accurate analysis
Due to the elastic properties of perfluoroelastomer a slight decrease in flow rate has been observed after long periods of energization.

Models incorporating the Zero-Internal-Volume diaphragm

  • STV series (2-way valve only)
  • MTV series
  • MLV series

Comparative Data Table


Model Type Internal Volume*
MTV-2-M6 Conventional 87 micro liters
MTV-2-M6N Zero-Internal-Volume 34 micro liters

*Passage volumes only.