VAT Vacuum Gate Valves: MONOVAT vs. VATLOCK Sealing Technology


An important consideration when choosing the appropriate vacuum gate valve for your system is seal technology. Factors such as size, particle performance, ease of maintenance, service lifetime, and others can be affected depending on the type of seal technology chosen. Currently, ANCORP offers VAT gate valves with two types of seal technology: MONOVAT and VATLOCK.


The MONOVAT sealing technology is featured on the Series 010 Mini UHV Gate Valve. The seal has a compact design with a vulcanized Viton gate. MONOVAT has easy maintenance and excellent particle performance. The design is also differential pressure proof in both directions and has a fast opening and closing time.

The closing sequence of MONOVAT is simple. The gate is moved forward into the closing position and the Vulcanized seal is then pressed against the seat.


The VATLOCK sealing technology is featured on the Series 012 Mini Gate Valve, the Series 108 UHV Gate Valve, and the Series 110 HV Gate Valve with Bellows. VATLOCK features a design that mechanically locks in the closed position. The design is differential proof in both directions and has low shock during operation. The VATLOCK mechanism on the Series 110 gate valve is rated to 200,000 cycles. For Series 108 and 110, the gate seal is vulcanized to the gate – a unique amongst gate valves on the market.

The closing sequence of VATLOCK involves four steps:

  1. Leaf springs hold the gate and counter plate against the carriage.
  2. The mechanism is moved forward into the closing position.
  3. The locking starts when the carriage meets the body. The ball retainers move the ball pairs out of the detents. Gate and counter plate are spread apart.
  4. The gate seal is pressed against the sealing surface without scuffing.


The MONOVAT sealing technology features easy seal maintenance, excellent particle performance and fast opening and closing time. The VATLOCK sealing technology provides flexibility in valve choice, a service life of 200,000 cycles, and a gate seal that is vulcanized to the gate.

To view our full lineup of VAT vacuum gate valves, visit our gate valves product page. For a complete catalog of VAT gate valve datasheets, visit our Manuals and Technical Data Sheets page.