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4.3
Back-pressure adapter O-ring
The back-pressure adapter connects the TD tube to the pump using an O-ring seal. It is recommended that this
O-ring is replaced every twelve months, or whenever it is noticeably damaged.
The ACTI-VOC is supplied with two spare O-rings (spares are also available for order as a pack of 10 – Markes
International part number
U-COV45
).
The O-rings can be replaced easily using Markes’ O-ring extraction and insertion tools (or other similar
implements) as described below.
•
Use Markes’ O-ring extraction tool (or similar pointed implement) to hook out the O-ring, taking care not
to scratch the groove in which the O-ring is seated, nor to damage the white PTFE insert behind.
Figure 6: Back-pressure adapter with O-ring extraction tool.
•
Take the replacement O-ring and push it into back-pressure adapter by hand.
•
Use Markes’ O-ring insertion tool (or similar blunt-ended implement) to locate the replacement O-ring into
the groove inside the back-pressure adapter.
Figure 7: Inserting a new O-ring into the back-pressure adapter.
•
Run the O-ring insertion tool around the inner diameter of the O-ring to ensure it is free from distortions.
