Stiling Well 1

[99491]

Dear All,

Will someone please tell me why stilling wells/slotted gauge wells have so many holes in the side to accommodate for the pressure and vacuum of the tank being filled or drained. Surely just a couple of holes near the top of the pipe would be sufficient depending on the filling and discharge rates. I have always found these to be over designed and would like some opinions.

Thanks

 

[IFRs]

The holes are required so that an accurate reading of liquid properties, content, temperature, etc are available at any elevation. The pressure and or vacuum are not really an issue.

 

[MJCronin]

99491....

Holes are cheap...

Extra hole provide insurance against gunk build-up and assure that tank cleaning cycles are not controlled by device build-up.

-MJC

 

[danielthb]

Over time without holes along the length of the well you wind up with the characteristics of the fluid inside the well being different from the fluid outside. It could make your hand cuts for gravity, density, whatever, or your ATG less accurate.

DB

 

[JStephen]

Suppose you have a stilling well that is only open at top and bottom.

You put 20' of water in the tank. Then add 20' of oil. Since all of the product has to enter the stilling well at the bottom, when you're done, the stilling well is full of water while the tank is half full of water and half full of oil. Due to different densities, the level inside and outside of the still tube could then be substantially different.

Not that this exact scenario takes place, but it seems to be the intent, that for accurate measurement of the level, the composition and temperature of the product in the stilling well needs to match that of the product outside at each level.