Practice Tips #74: Infection Control (Part 1)

We are going to tell you a few tricks to keep your vacuum facts straight in today's Practice Tips #74: Infection Control.

The assistant’s instrumentation (particularly the high volume evacuator valve) is your first line of defense in infection control as it reduces contaminated aerosols which can spread blood borne pathogens which can contribute to cross-contamination.

The high volume evacuator (HVE) and saliva ejector (SE) valves often collectively referred to as the “assistant’s instrumentation.” Both systems connect to a collection canister or commonly referred to as a “chairside trap.”

The Collection Canister Serves Two Primary Functions:

First Function: Splits the main vacuum line from the central vacuum, so you can have multiple vacuum valves in the operatory.30-60_PORTS

Second Function: Filter solids picked up by the HVE valve(s
  • As you can see in the photo above, the HVE ports pokes up through the collection canister, so solid debris picked up catches in the basket.
  • The SE normally only picks up liquids, so the SE port does NOT penetrate the basket. 

Three Styles of Collection Canisters (Referred to as Types “A”, “B,” and “C”):

Type “B” Canisters

Have a ½” outside diameter port to connect to the central vacuum line (the same size as the HVE ports). This is also the smallest canister with a basket (filter screen) that is only 1-7/8” in diameter. Because of the small size, the HVE ports are off center. This off-center design is unique to the type “B” canister. If using color-coded baskets, the baskets for a Type “B” canister are green. Read more about the ABC's of canisters and infection control in Practice Tip #121.

NOTE: HVE holes are off center due to the smaller size of the basket

Image Notes: HVE holes are off center due to the smaller size of the basket (1-7/8" diameter. Item #18-91.

Type “A” and type “C” Canisters

Both canister styles have a 5/8” port to connect to the line from the central vacuum (“drain port”), so they can offer superior suction. The overall size of the canister is bigger and they accept a basket that is 2-1/8” in diameter. The larger size allows placing the HVE ports along the diameter of the canister (and basket). There are other older designs that have this feature as well, however, so having ports along the diameter is not a clear indicator of which canister (or basket) one might have. If using color-coded baskets, the basket for the type “A” and “C” canisters is blue.


Image Notes: HVE ports are centered due to the larger size of the basket (2-1/8" diameter. Item #18-90.

Distinguish the “A” and “C” canisters by the location of the drain port. The “A” canister has the 5/8” drain port on the bottom of the canister. The “C” canister has the port coming out of the side of the canister.

The side drain allows the “C” canister to be used at the end of a telescoping arm (#08-98 for example) or in other configurations that may not allow for a drain on the bottom. With a telescoping arm mount, the side port allows the drain line to feed through the arm. This aids in asepsis and gives the unit clean aesthetics.


Image Notes: There is a lack of visible drain lines in #08-98.

In Practice Tips #74: Infection Control (Part 1) we've learned that when you look at vacuum canisters and debris baskets in such a way, they aren't that intimidating. Just remember to watch out for the location of the HVE ports of the canister and the correlating baskets.


Please note, comments must be approved before they are published