Static head in Hydrotest in Horizontal position

[John121]

Static head added in design pressure of Hydro test in Horizontal vessel position? I don't know exactly but there is one addendum to code to not consider Static head. Can anybody have reference of that addendum.

 

[Raai2015]

As per EN12952-3 ; if the static head is less than 0,5bar than it shall be neglected!

 

[Jay_]

The hydrotest shall be done as per UG-99 at a pressure not less than the specified per the paragraph, at the top of tank.

Detailing is a hobby,

 

[SnTMan]

...there is one addendum to code...

Care to reveal WHICH Code?

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[marty007]

For ASME, there is one interpretation that I've used a few times:

Interpretation Number : VIII-1-95-27

Question(s) and Reply(ies):
Question (1): Does the last sentence of UG-99(b) of Section VIII, Division 1, "All loadings that may exist during this test shall be given consideration," require that the static head that exists in a tower in the vertical position must be considered when determining the test pressure in the horizontal position?

Reply (1): No.

Question (2): Does UG-99 specify in which position a vertical tower must be hydrotested?

Reply (2): No.
​

 

[John121]

Thank you marty007. I want this. Interpretation Number : VIII-1-95-27
vertical static head should not considered in horizontal hydro test condition.

 

[SnTMan]

Yeah, you just need to be sure the vessel will never be hydro'd verrticaly...

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[r6155]

Question (1) and Reply (1): this interpretation distorts the concept of hydrostatic test. In my specifications I do not allow it.
This interpretation is only for UG-99 (b),it is not applicable for UG-99 (c) special test

Regards

 

[marty007]

I think this interpretation has an appropriate time and place for use.

When designing a simple carbon steel pressure vessel, the additional cost to make the design able to withstand a vertical hydrotest can be minimal.

If however you are designing a thin-walled titanium tower, the additional cost to make the tower able to withstand a vertical hydrotest may be significant.

In the software we use it is very easy to turn on/off hydrotest cases for vertical and horizontal tests. So, I often run the vertical test case just to see if it leads to any problems. Depending on what changes would need to be made, and the material of construction for the vessel, we make a judgement call if designing for a vertical test is reasonable.

All that aside, if a customer spec requires the vessel to be designed for a vertical test, then we design for the vertical test...

-Marty

 

[r6155]

I am not going to risk my prestige and the safety of a pressure vessel due to the cost of the hydraulic test. I always did it with responsible manufacturers.

Regards