Tank Alteration/Modification

[lightseeker123]

Hi
We are planning to add a 6"- 12" repad on the floor of a self supporting conical roof water storage tank. A point load will be connected at that location, away from critical heated affected zone. Do we need to conduct hydrotest after that. As per 9.3.3, pad can be added complying with NDE requirements but checking section 12, hydrotest not required, i could not find a strong reference that hydrotest is exempted.
Thanks,

Lightseeker123

 

[LurmClaxton]

What is the pad for?

Personally I wouldn't request a hydro for adding a welded pad on a tank floor

 

[Duwe6]

API-650 / 653 gives the Inspector of Record a *lot* of leeway. Thus, a lot of 'gray areas' in the Code. Unless your Inspector has been given reason to hate you, no hydro will be required - reasoning; did not infringe on any weld seams, did not change any openings nor do any work that falls under Alteration definition.

 

[lightseeker123]

Tank is newly built and hydrotested, not put into service yet but it is decided to add a repad for bolting a point load on the floor.We are trying to figure out hydrotest requirement apart from floor vaccum test. We will limit repad size to exempt hydrotest.
As this is not a major repair we may not need rehydhydro.