Tank Wall Hole: The diameter of the hole through the tank should be equal to, or up to 1/32” larger that the nominal Body O.D. Do not exceed this size or the o-ring may not seal properly.
Inserting the Fitting: The fitting, together with the o-ring, should be installed from the inside of the tank.
Sealing Surface: The o-ring sealing surface should be smooth and free from sharp edges, burrs, and deep scratches. Ideally, it should have a 20 micro-inch or smoother finish although depending upon the characteristics of the surface, the o-ring will often achieve a seal against rough surfaces.
Tighten Nut: When tightening nut, bring it to the point at which the o-ring seal is just in contact with the tank wall. Then tighten it approximately as shown in the following table:
|Nominal Pipe Size
|1/4” – 1/2”
||2/3 of a turn|
|3/4" – 2-1/2”
||1/2 of a turn|
|3” – 4”
||1/3 of a turn|
Achieving the Seal: Sealing to a less than smooth surface with Teflon® PFA encapsulated o-rings is different than sealing with rubber o-rings. A rubber o-ring will immediately deform into surface imperfections; Teflon® takes time. Thus, the o-ring may leak when installed. To correct this situation, allow the o-ring to settle in place overnight. This allows the Teflon® to cold-flow into the voids. Alternatively, you can heat the o-ring, allowing it to flow more quickly. If a seal is not achieved, it may help to take-up a little more on the nut.
Title: How to properly install the PTFE Bulkhead fittings?
Description: Installation instructions for the PTFE Bulkhead fittings.
Last Edited: 9/18/2013
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