Goodmorning,
If i have to test a column, and i want to make orizontal hydraulic test,
is it necessary to increase te test pressure calculated by the head?
Thanks,
francesco

Welcome to the forum Francesco,

please go the the following topic: http://www.onetb.com/forum/ftopic818.html, this will answer your question.

Michael

YES.
HEAD WILL BE ID OF VESSEL.

.
Test prssure read on top of the vessel in horizontal position shall be at least that required.
Mauro

Hi tester.
Testing a column is a verry delicate situation, first you should review the colum design drawings for material thickness.
Some colums have diferent thickness at various levels or rings. Some are thicker at top due to distilation material corrosion effect. Some are thin and have an internal cladding to protect the structural steel from corrosion effect of ladding material.
The static liquid pressure will varied at a rate of .43 pounds per feet. So test pressure gage will give a different reading in accordance to level of gage location. This would be Absolute pressure + liquid head pressure= Test pressure

An internal and external inspection should be perform in order to determine remaining thickness of all ring which combine structure.
Once all corroded areas are gaged or repaired and there is no pitting or metal wear of any of the element, unit must be rated for the AWP. Ussually the top section ring and head will give you your testing pressure calculation.
Many colums are design of varrious material at diferent level, for example crude destilation system have a bottom section of S.S. material this condition will also varied your hydrotest pressure.
Well the stress material could varied and your test pressure calculation will varied .
Never exceed your hydro above top shell ring desing pressure when testing colum on ground horizontal position.

Iff tested verticaly, always have a pressure gage at the top head and radio operator watching the gage continiously. Also make shure the vessle does not exceed its 10% lineal expansion. You could make a permanet vessel deformation during hydro test.

I have been a AI for thirty years , and I always use my UT and confirm for pressure vessle shell thickness, I do some ASME calculation and confirm for AWP on vessles elements, prior doing a hydro. Not always what you see on the Drawing and the Manufacturing data sheet comply with what is on the equipment a change could have been done and not revised on drawing. So always act safe, do your calculation prior doing your hydro, you will end up economising a lot of money to end user.

Also remember hydro test pressure is a distructive test, when ever you can test a used pressure vessel try to test to 1.5 operating pressure , never do 1.5 design. If your inspector is a good inspector, only new construction is required to be tested to 1.5 design.

Frequent hrydro static test will generate unnesesary stress, I have personaly met a lot of code inspector that insted of testing they junk equipment, remember during testing their is no insurance coverage. So watch what your inspector is making you do during hydro. Ask him if he accepts 1.5 operational pressure testing on used equipment.

Hope this helps a little.