Hydrotest Pressure of Newly procured tubes
Hydrotest Pressure of Newly procured tubes
(OP)
We are planning to re-tube one of our condensers. The tubes OD is 25 mm and thickness is 2.2 mm with material ASTM A179. Please advice what hydrotest pressure should we specify for the preshipment HYDROTEST.





RE: Hydrotest Pressure of Newly procured tubes
rmw
RE: Hydrotest Pressure of Newly procured tubes
Thank you very much for replying.
The design pressure in this case is 8.4 Kg/cm2. So the test pressure for tubes should be 8.4 x 1.3 = 10.9 Kg/cm2. But when I dug out the ASTM standard A540 (Specification for general requirements for carbon steel tube), it mentioned the hydrostatic test pressure by following:
22. Hydrostatic Test
22.1 Except as provided in 22.2 and 22.3, each tube
shall be tested by the manufacturer to a minimum hydro-
static test pressure determined by the following equation;
Inch-Pound Units: P = 32000 l/D (3)
Si Units: P = 220.6 t/D
where:
P = hydrostatic test pressure, psi or MPa,
t = specified wall thickness, in. or mm, and
D = specified outside diameter, in. or mm.
According to this standard this comes out to be:
P = 220.6 x 2.2 / 25.4 = 19.1 MPa (190 Kg/cm2 !!!!!!!)
Please note that this standard is also applicable to A179 tubes
I am surprised that on th e basis of design pressure of the equipment, the test pressure should be 10.9 Kg.cm2 but the code has specified it as 190 Kg/cm2!!!!!! how is so much difference???
RE: Hydrotest Pressure of Newly procured tubes
Or NOT!!! Sometimes they will cut corners or make assumptions which is why I recommended asking them to what pressure do they hydrotest. That will answer two questions; (1) whether or not they do in fact hydrotest, and (2) if they do, to what pressure.
rmw