Gauge Pole Cover for IFR Tanks

[KVARM]

is this possible to provide gauge pole cover for IFR tanks. Normally supplier using cover on deck and 5" clearance is there between still well pipe and the cover and this gab is to be covered by using seal materials.

 

[IFRs]

Yes you can, but I think a well gasket / sliding cover / pole wiper / pole sleeve combination is considered equivalent by regulators while being more reliable and less likely to have maintenance issues or cause problems with the floating roof. Covers are more common on external floating roofs where wind effects need to be reduced and with steel internal floating roofs as opposed to aluminum or other lightweight internal floating roofs. One question I have never gotten a good answer to is what happens to the vapors inside the cover when the volume inside the cover is reduced as the floating roof moves upwards. My guess is it just escapes and this is not accounted for in emissions estimates.