Piping Systems
Vacuum control piping must be correctly designed with respect to separators, droplegs and headers. The header needs to be sized to supply sufficient vacuum to each low and high-vacuum area. Also, the droplegs in each section need to be sized to provide sufficient area to evacuate the water removed by each table structure. The recommendations used are industry and Kadant AES standards, and can be adopted as a guideline only.
High Vacuum Applications
Typical Layout for Vacuum Piping and Control
Header: Size for air velocity < 3000 ft/min
Standpipe: Sized as function of the V-1000 valve size
3" Valve = 4" Standpipe
4 & 6" Valve = 8" Standpipe
8" Valve = 12" Standpipe
Separator: Size for air velocity < 500 ft/s
Box outlet & Separator inlet
Size for air velocity < 3000 ft/s and water velocity < 3ft/s
Dropleg: Size for water velocity < 3 ft/s
Low Vacuum Applications
Typical Layout for Vacuum Piping and Control
Header: Size for air velocity < 3000 ft/min
Standpipe: Sized as function of the V-1000 valve size
3" Valve = 4" Standpipe
4 & 6" Valve = 8" Standpipe
8" Valve = 12" Standpipe
Separator Inlet :
4" for fabric width < 260 inches
6" for fabric width > 260 inches
Size for air velocity < 500 ft/s
V 1000 sizing : (Use sizing curves if in doubt.)
Wire width < 200" & Air flow < 300 cfm ' 3" V-1000
Wire width > 200" & Air flow > 300 cfm ' 4" V-1000
If DP high & Air flow > 500 cfm ' 6" V-1000
Vacuum Header
Vacuum header sizing is based on the principle of flow velocity through a pipe. AES vacuum headers are sized for an air velocity of 5000 fpm through the selected pipe.
Vacuum Separator
As with the vacuum header, the vacuum separators are sized for specific air velocities through a pipe. The AES vacuum separators are sized for an air velocity of 500 fpm through the selected separator.