Significance of Hydrotest load in Spring Selection

Hello All,

Can anyone explain me the significance of Hydrotest load on SPring purchase??

Thanking you in advance

COS,

In site construction after the installation of the pipes, some critical lines or process lines will undergo hydrotest. Then the pipe line with spring support will experience that hydrotest load. Now the vendor should anticipate how much is the hydrotest load for much accurate and efficient
spring support should be installed.


YOCH

Hi COS
At the time of hydro test we have to use lock pin in spring . So spring support will act as rigid hanger instead of spring hanger. Once hydro test over line ready for operation unlock the spring. In general there should not be much problem unless hydro load at that point unacceptably high.
vendor should be informed for hydro load for rigid design of spring hanger.

Hi COS,

As per my observation the hydrotest load will be less when you compaire the loads on hot condition. Because when you lock the hanger in hydro test then it only takes the pressure force as well as the dead weight.

But still you have to check the load on that perticular point in all the cases.

Hi Rk
Hydro load may be less in some specific case but not at all cases.
As per example say in steam line you are using spring, operating fluid weight almost zero . At the time of hydrotest line is totally filled with water hence dead weight also very high.

Hi Shr,

I will again stick with my point. As In hydrotest only you are concering about the 1000 K.G./m3 of density but there are more other factors like thermal loads, insulation load etc. And because of all these in hydro test load hopefully will not be more.

At least I have not seen any of such case in my professional life. If you have such kind of example, request you to please send it to me for study.

Thanks.

Many, many hot lines in a pertochemical facility are VAPOR lines, thus the Hydro loads will be greater than the operating spring loads. For larger diameter lines the Hydroloads can be 2 to 3+ times greater than the Vapor operating loads. The thermal loads on a spring are LOW (< 25% +/- of installed load)

Usually the springs are capable of safely supporting 2 times the rated load. Special designs/coordination with spring vendor is required above this limit.

Bob, I was getting nervous at the direction this thread was taking as I read down the posts. I'm glad you capped this thread with a clear summary of the real issues. I agree completely with Bob on this one.