API 650 question 2

[CWI003]

Hi ,


Hi everyone ,

I have a question for the paragraph 5.8.1.2.a in API 650 13 th , when the anchor chair or stair is welded directly to the shell as per the pictures does it violate the code ?

also table 5.18 part 3


there are a gaps between the tread at the end so is that violating the code requirements ?

pictures attached

 

[HTURKAK]

My opinion based on experience is ,

Telltale holes ( threaded internally ) is also necessary to detect leaks from nozzle or manway welds during service.
The holes can be plugged using heavy grease. I have witnessed also Telltale holes plugged with bolt. ( the maintenance eng. said , the bolt is taken out to check if there is leak during periodic maintenance)..








If you put garbage in a computer nothing comes out but garbage. But this garbage, having passed through a very expensive machine, is somehow ennobled and none dare criticize it. ( ANONYMOUS )

 

[IFRs]

5.7.2.10 Each reinforcing plate for shell openings shall be provided with a 6 mm (1/4 in.) diameter telltale hole. The
hole shall be located on the horizontal centerline and shall be open to the atmosphere.

5.7.5.1 .... Each manhole reinforcing plate shall be provided with a 6 mm (1/4 in.) diameter telltale hole (for detection of leakage through the interior welds). The hole shall be located on the horizontal centerline and shall be open to the atmosphere.

Both sections say "shall" be open to the atmosphere.
That is pretty clear!

My opinions:
Why should they be open? - to able to show leakage.
When? For me, it should be as long as you want to call it an API 650 tank.
I'm OK with filling the telltale holes with heavy grease since that still allows leakage to show without allowing water in which might freeze and damge the tank or foster corrosion.

 

[r6155]

See:
7.3.5 Inspection of Reinforcing-Plate Welds
After fabrication is completed but before the tank is filled with test water, the reinforcing plates shall be tested by the Manufacturer by applying up to 100 kPa (15 lbf/in.2) gauge pneumatic pressure between the tank shell and the
reinforcement plate on each opening using the telltale hole specified in 5.7.5.1. While each space is subjected to such pressure, a soap film, linseed oil, or another material suitable for the detection of leaks shall be applied to all attachment welding around the reinforcement, both inside and outside the tank

Regards

 

[CWI003]

Dear All ,

thanks for all of your help and the time you spend answering and sharing your knowledge .