Installation, Operating & Maintenance Instructions 
Series 650 DN 100-250 (I.D. 4“ - 10”), CC-Link 
 
 
 
VAT Vakuumventile AG, CH-9469 Haag, Switzerland 
Tel +41 81 771 61 61   Fax +41 81 771 48 30   CH@vatvalve.com www.vatvalve.com 
280672EB 
2010-12-15 
77/94 
 
5.1 Maintenance procedures 
 
 
 
Keep fingers out of the valve during maintenance work. 
 
 
Use cleanroom gloves during maintenance work. 
 
 
Two preventive maintenance procedures are defined for this valve. These are: 
 
• Replacement of isolation seals (gate and body seal of sealing ring) and valve cleaning 
 
• Replacement of actuator and actuator shaft seals 
 
Required frequency of cleaning and replacement of seals is depending on process conditions. 
 
A critical factor influencing the maintenance period is the lifetime of the vacuum grease, being limited under 
increased temperature. In this case grease will separate to PTFE and oil. The oil may flow and contaminate 
the valve parts. 
 
 
VAT can give the following recommendations for preventive maintenance: 
 
  unheated *) 
heated ≤ 80°C *) 
heated > 80°C *) 
isolation seals (gate and body seal of sealing ring) 
200’000 cycles  6 months but 
max. 200’000 cycles
3 months but 
max. 200’000 cycles
actuator shaft seals 
1’000’000 cycles  6 months  3 months 
 
*) This figures are reference values for clean conditions under various temperatures. These values do not include any 
impact of the process. Therefore preventive maintenance schedule has finally to be checked for the actual process 
conditions. 
 
Prevent gap between body and sealing 
ring from air gun cleaning. Otherwise 
vacuum grease may be distributed and 
contaminate the valve. 
 
 
valve body 
gap
sealing ring
pendulum plate
 
 
 
 
Replacement of isolation seals (gate and body seal of sealing ring) and valve cleaning 
 
 
Replacement of actuator and actuator shaft seals