External Vacuum Support for FS, Duplex, and Inverted Style Graphite Disks

The ZOOK External Vacuum Support is designed to enable low-rated Duplex style rupture disks to withstand full vacuum conditions, particularly in highly corrosive and low-pressure environments, by providing a robust and reusable PTFE support system.

Before the development of ZOOK’s external vacuum support, few options existed for the user that required a rupture disk in a highly corrosive, low-pressure, full vacuum application. The best option was a PTFE Mono style disk with a vacuum support. The external vacuum support is a device that offers low rated Duplex rupture disks the ability to withstand full vacuum. By offering a Duplex disk with an external vacuum support, the user can now meet all three requirements.

• The external vacuum support may only be used with a ZOOK FS or Duplex or Inverted style graphite rupture disk.
• Duplex style disks rated less than 25 psig will not withstand full vacuum without this support.
• Duplex style disks rated 25 psi or greater do not require this support as they will withstand a full vacuum.
• The external vacuum support installs on the process side (vacuum side) of a Duplex disk.
• The vacuum support consists of a solid plate of PTFE with an O-ring groove machined into the support surface. A Viton O-ring creates the seal between the process side of the Duplex disk and the external vacuum support. The plate is precision drilled and has optimum free flow area. Consult ZOOK for availability of other O-ring materials. Other support materials are available upon request.
• The external vacuum support is reusable.
• The external vacuum support is provided with an adhesive label with the following information; material of construction, manufacturer, flow direction, size and part number.

Caution

• Prior to reinstallation, a visual inspection must be performed to verify the condition of the support. No damage to the support sealing surfaces or O-ring groove should be evident.
• The O-ring should be replaced each time the external vacuum support is reused. Replacement O-rings are available from ZOOK.
• All sealing faces must be clean, flat and parallel.
• Refer to drawing ZP 3842B for proper orientation (see image below).
• Flow direction on tags of disk and external vacuum support must both point in the proper vent direction.
• Users should consider the vacuum support for free area while performing sizing calculations. See Table below from ZOOK drawing ZP 3842B.
• The vacuum support will reduce disk flow area. Proper use of this device and/or determination of adequate flow is the responsibility of the user.