Question

A) INTI Oil Company, is designing a double-layer pipe to be placed on sea bed to carry the
Oil (and gas) with the pressure of 50 MPa. The corrosive sea water exerts 10 MPa of
pressure on this pipe, hence the outer layer is chosen to be 303 stainless steel with outer
diameter of 60 cm. Select a proper cold drawn steel as inner layer material of this pipe
with bore diameter of 20 cm and outer diameter of 50 cm.

B) After material selection, assess the safety factor of the system.

Answer 1

A yield Strength (Sur) m 2t Ang) =) for pipe at any point of time longitudinal Stouss (oral and houp Storers (Oh should be less than ultimate yield strength to avoid failure of pipe Tong = pp. long ut . Since In Tong so If pine can sustain houp stress than it can also sustain longitudinal Stress D = 50 cm t = Do-DT 50-20 = 15cm 2 2 T PD - 50 x 50 = 83.33 MPa 2 X 15 care 2. So the working material should having the Yield Strength more than 83.33 MPa SS 303 also have Yield Stoength of 415 MPa so we can also choose SS 303 for given Condition, fortor of safety N = Sut = us un 83.33 = 4.98 5 . Scanned with CamScanner