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Procedure for Changing Twin-O-Vac Bacteria Filters


The Twin-O-Vac is an oxygen powered suction system that also has two high-pressure outlets to attach auxiliary equipment such as flowmeters. To protect the operator and patient from the possible transmission of air and fluid borne bacteria, the system also incorporates two viral bacterial filters.

This article will explain the process of changing these filters.

Please note: Filters must be changed after every use of suction, particularly between patients!

Steps to changing filter: –

1. Ensure that you are in a clean and traffic free environment.
2. Fit surgical type gloves or equivalent.
3. If using oxygen from cylinders, turn cylinder OFF by rotating handwheel clockwise.
4. Drain gas in regulators and Twin-O-Vac by turning suction ON, then OFF when depleted.
5. Remove all attachments, such as flowmeters and suction hose.
6. Loosen handwheel, attaching Twin-O-Vac to regulator, slightly.
7. Rotate the Twin-O-Vac so it is upside down, and then tighten white handwheel slightly.
8. Remove suction trap jar.
9. Slide the flat metal plate off the chrome cap.
10. Remove the cap and the old filters, as well as any debris. (If cleaning at this point, go to point 1 of cleaning procedures).
11. If blue separator paper is with new filters, discard this. Failure to do so will result in the equipment not functioning correctly. (Two filters are required 1 thick and 1 thin)
12. Place first fine filter on gauze retainer, within indentation.
13. Place second coarse filter on top of the fine filter.
14. Ensure filters are seated centrally.
15. Place cap on filters centrally.
16. Slide flat retaining plate across and over to top of cap.
17. Replace clean, preferably cold sterilized, jar.
18. Rotate Twin-O-Vac back to vertical and tighten handwheel.
19. Re-apply attachments (flowmeters, hoses, etc.)
20. Turn gas on and test system by turning suction on and kinking hose or occluding inlet.

Points of Interest

  • When in operation, the Twin-O-Vac exhausts a high flow of oxygen via an exhaust port at the top rear of the unit. This can be incorrectly perceived as a loud leak, but however is normal operation.
  • The vacuum gauge on top of the unit will only indicate when there is fluid suction or the inlet is occluded either partially or fully.
  • The blue separator paper must be discarded, as it is not a filter and may cause failure of the unit.