API 510 Math questions

A pressure vessel has an MAWP of 500 psi at 400°F and is made of SA-516 Grade 70 material with a
stress value of 20,000 psi and has a measured thickness of 0.875 inches. The efficiency is 1.0, the inside
radius is 24 inches and there is no corrosion allowance. The observed corrosion rate is 0.01 inches/year
and the next planned inspection is 5 years. What will be the MAWP at the end of five years?

A pressure vessel has an MAWP of 350 psi at 300°F and is made of SA-515 Grade 60 material with a
stress value of 16,000 psi. The efficiency of the longitudinal joint is 0.70 and the inside radius is 36 inches
with a 0.125 inch corrosion allowance. The measured thickness is 0.750 inches and the corrosion ,"ate is
0.020 inches per year. The next planned inspection is in 6 years. What will be the MAWP at the end of six
years?

An eight foot diameter vessel has a large area of general corrosion (32 in. in length and width) and has
thickness readings taken in the circumferential (Iettered rows, ego 1 a, 2a, 3a,) and longitudinal (numbered rows, 1 a, 1 b, 1 c) directions as shown below. What would be the least thickness along the most critical element considering longitudinal joint?
1 a~0.298"
1 b-O.264"
1 c-O.223"
2a-O.243"
2b-O.230"
2c-O.180"
3a-O.192"
3b-O.185"
3c-O.204"
4a-O.185"
4b-O.193"
4c-O.210"
5a-O.267"
5b-O.220"
5c-O.246"

A six foot diameter vessel has a large area of general corrosion (24 in. in length and width) and has had
thickness readings taken in the circumferential direction (numbered rows, ego 1 a, 1 b, 1 c) and in the
longitudinal direction (lettered rows, ego 1a, 2a, 3a,) as shown below. What would be the least thickness
along the most critical element considering the circumferential direction?
1 a-0.456
1b-O.458
1c-O.398
2a-0.443
2b-0.423
2c-O.399
3a-O.388
3b-O.334
3c-O.368
4a-0.443
4b-0.457
4c-0.447
5a-O.550
5b-O.589
5c-O.498

A pressure vessel is 48 in. in diameter. There is some widely scattered pitting present. The wall thickness including a 0.125 in. corrosion allowance is 0.750 in. One group is encircled by an eight inch diameter circle that contains the following:

One 1" dia. x 0.20" deep pit, three 3/4" dia. pits x 0.20" deep pits and, one 1-1/2" dia. x 0.15" deep pit. A straight line is drawn through the most pits within the circle and includes the 3/4",1", and 1.5" pits.

a. What is the total area of the pits within the 8 in. circle?

Problem # 5
A pressure vessel is 48 in. in diameter. There is some widely scattered pitting present. The wall thickness including a 0.125 in. corrosion allowance is 0.750 in. One group is encircled by an eight inch diameter circle that contains the following:

One 1" dia. x 0.20" deep pit, three 3/4" dia. pits x 0.20" deep pits and, one 1-1/2" dia. x 0.15" deep pit. A straight line is drawn through the most pits within the circle and includes the 3/4",1", and 1.5" pits.

b. What would have to be done to the pits in the straight line to make them acceptable?

A pressure vessel is found to have a corroded area that includes the longitudinal welded seam. An evaluation must be made to determine whether the thickness al the weld or remote from the weld governs. The inside radius is 36 in., which includes a 0.125 in. corrosion allowance. The MAWP is 500 psig, S'" 17500 psi, the nameplate has no extent of radiography shown under the Code symbol stamp. The longitudinal welded sea m is Type 1. What would be the width of the band of the weld as a result of the evaluation if the width from toe to toe was 1.000 in?

There has been corrosion in the center of an ellipsoidal head. The head is a 2: 1 elliptical with a D of 60 inches and an h of 15 inches. What is the required thickness in the center portion of this head if the MAWP is 300 psi, E'" 1.0 and the S = 15600 psi ?

A torispherical head is found to have corrosion in the center portion. The crown radius is 36 inches, the MAWP is 450 psi, S '" 20,000 and UW-11(a)(5)(b) has been applied. What is the required thickness in the center portion of the head?

A pressure vessel shell has a measured thickness of 0.678 inches and a required thickness of 0.570 inches. The short term corrosion rate is 0.023 inches per year- and the long term corrosion rate is 0.015 inches per year. What is the remaining life of the shell?

The bottom head of a vessel has had the following thickness readings taken since being put into service in 1997. 1997 = 0,750",1999 = 0.720", 2000 = 0.650",2002 = 0,623", The required thickness is 0.553 in, What is the next inspection interval?

The following readings were taken for a pressure vessel. New in 1992 - 0.689", 1994 - 0.527", 1996- 0.500", 1998 - 0.467". What is the short term corrosion rate?

The following readings were taken for a pressure vessel. New in 1992 - 0.689", 1994 - 0.527", 1996- 0.500", 1998 - 0.467".
what is the long term corrosion rate?

A torispherical head is to be repaired by replacement of the center portion of the head. What is the required thickness for a dished repair plate that is 50% of the head diameter, the material is SA-516 Grade 70 and S = 18,000, P = 300 psi, the crown radius is 96 in" E=0.65 and a Type 2 joint will be used.