tank roof drilling / tank roof integrity

[wikinfo]

Hi,
for cleaning operation we need to drill holes (3” to 4”) on tank roof in order to bolt a cleaning device number of holes vary base on size, our problem is to have engineering document to support out operation and gives documented warranty of the roof integrity after the job is performed, our client is basically asking for guaranties backed by an engineering calculations, if you know procedures standards or any similar situation that involve roof modification please help
Thks.

 

[bimr]

The weight of the equipment will be more important than the holes.

 

[wikinfo]

the weight is really not an issue and was not of any concerns for our client, the guaranty that it will not affect the structural integrity and safety, this was their main concern and we do understand their point,

 

[bimr]

You will need to follow whatever code the tank was fabricated. API 653 Rank Inspection, Repair, Alteration, and Reconstruction allows the use of a 12-Inch patch.

If it is a pressure vessel, this would not apply.

You will have to look up the issue in the code the tank was fabricated.