API 570 Practice Questions (Numbers Only) All Questions Are Closed Book
API 570 Practice Questions (Numbers Only) All Questions Are Closed Book
API 570 Practice Questions (Numbers Only) All Questions Are Closed Book
API 570
1)
3) A NPS 6 (6.6.25" od) seamless pipe made from ASTM A335 Grade P2 material
operates at 800 psi and 600 degrees F. The conditions require that a corrosion
allowance of 0.125" be maintained. Calculate the minimum required thickness for
these conditions.
4) A NPS 14 (14.00" od) seamless pipe made from ASTM A106 Grade A material
operates at 300 psi and 600 degrees F. The pipe must cross a small ditch and it must
be capable of supporting itself without a visible sag. A piping engineer states that the
pipe must be atleast 0.375" to support itself and the liquid product. He also states that
a 0.125" corrosion allowance must be included. Calculate the minimum required
thickness for the pipe.
5) A 10' long carbon steel pipe is welded to a 10' 18-8 stainless pipe and is heated
uniformly to 475 degrees F from 70 degrees F. Determine its total length after heating
6) A blank is required between two NPS 10, 300 lb. class flanges. The maximum
pressure in the system is 385 psi at 200 degrees F. A corrosion allowance of 0.175" is
required. The inside diameter of the gasket surface is 9.25". The blank is ASTM A516
Grade 70 material with no weld joint. Calculate the pressure design thickness required
for the blank
7) A NPS 14 (14.00" od) seamless pipe made from ASTM A53 Grade B material
operates at 600 psi 600 degrees F. Calculate the pressure design thickness for these
conditions.
P = 2SEt
D
a) 0.243" b) 0.442" c) 0.205" d) 0.191"
a) 0.01996"/year b) 0.02567"/year
c) 0.02114"/year d) 0.03546"/year
9) Using the data in Question No. 8, calculate the short term corrosion rate in mils per
year (M/P year)
10) Using the information in Questions No. 8 and No. 9, determine the remaining life of
the system
11) Using the information in Questions No. 10 and assuming an injection point in a Class
2 system with 7 years estimated until the next inspection what would the next interval
be
12) A seamless NPS 10 pipe, ASTM A106 Grade B material operates at 750 psi and 700
degrees F maximum. Considering only pressure design thickness, what minimum
thickness is required ?
13) A seamless NPS 16 pipe, ASTM A135 Grade A material operates at 550 psi and 600
degrees F maximum. The thickness of the pipe as determined by the last inspection is
0.40". The pipe has been in service for 8 years. The original thickness at installation
was measured to be 0.844". Two years previous to the 0.40" measurement the
thickness of the pipe was found to be 0.54". Determine the greatest corrosion rate,
i.e. short or long term in mils per year (M/P year)
14) A seamless NPS 12 pipe, ASTM A106 Grade B material operates at 750 psi and
700 degrees F maximum. The thickness of the pipe as determined by the last
inspection is 0.305". The pipe has been in service for 13 years. The original thickness
at installation was measured to be 0.405". Two years previous to the 0.305"
measurement the thickness of the pipe found to be 0.316". The next planned
inspection is scheduled for 8 years. Using the appropriate corrosion rate determine
what MAWP the pipe will withstand at the end of the next inspection period
15) A seamless NPS 6, ASTM A106 Grade A pipe operates at 300 degrees F and 765 psi.
The allowable stress is 16,000 psi. Using the Barlow equation, determine the required
thickness for these conditions
16) A seamless NPS 6, ASTM A106 Grade A pipe operates at 300 degrees F and 741 psi.
The allowable stress is 16,000 psi. The owner-user specified that the pipe must have
0.125" for corrosion allowance. Using the Barlow equation, determine the required
thickness for these conditions
17) A NPS 4 Schedule 80 (0.337" wall) branch connection is welded into a NPS 6
Schedule 40 (0.280" wall). A 0.375" reinforcing pad is used around the branch
connection. The fillet weld sizes are as required by the Code. The branch connection
is inserted into the header. The material of the branch and header is ASTM A672
Grade B70. What thickness would be used to determine whether heat treatment of the
connection is required ? (Express answer to nearest hundredth)
18) An inspector finds a thin area in the body of a NPS 6, 600 lb. gate valve body. The
body is made from ASTM A216 WCB material. The system operates at 900 psi and
750 degrees F. Using a corrosion allowance of 0.125", what minimum required
thickness must the valve body have to continue to safely operate ? (Round to the
nearest 3 decimals)
19) A seamless NPS 10 pipe, ASTM A106 Grade B material, operates at 750 psi and 700
degrees F (maximum). The thickness of the pipe as determined by the last inspection
is 0.30". The pipe has been in service for 10 years. The original thickness (measured
when installed) was 0.365". Two years previous to the 0.30" measurement the
thickness of the pipe was measured to be 0.31". Determine the greatest corrosion rate
i.e. short or long term
20) A seamless NPS 10 pipe, ASTM A106 Grade B material operates at 750 psi and 700
degrees F (maximum). The thickness of the pipe as determined by the last inspection
is 0.30". The pipe has been in service for 10 years. The original thickness (measured
when installed) was 0.365". Two years previous to the 0.30" measurement the
thickness of the pipe was measured to be 0.365". Two years previous to he 0.30"
measurement the thickness of the pipe was measured to be 0.31". The next planned
inspection is scheduled for 7 years. Using the worst corrosion rate (short or long term)
determine what pressure the pipe will withstand at the end of its next inspection
period ?
ANSWER KEY