653 & 650 - P3 (50Q) Flashcards
Peaking shall not exceed ½” when measured with:
A horizontal sweep board 36” long and made to the true outside radius of the tank.
Routine in-service inspection includes:
Visually checking the exterior tank’s surface for leaks, shell distortions, signs of settlement, signs of corrosion, condition of foundation, condition of paint, condition of insulation system, and condition of appurtenances.
Corroded roof plates shall be repaired or replaced, when the:
Average thickness is less than 0.09” in a 100 square inch area.
Hydrostatic test stress for a new tank is based upon:
The lesser of ¾ the yield stress or 3/7 the minimum tensile stress of the tank’s material of construction.
If the number of elevation measurement points is determined by N = D/10, how many measurement points are necessary on a 50 feet diameter tank?
8
The joint between the new material of an insert plate and the old material of the existing tank shell plate shall be:
Butt welded.
It has been determined that L=32” in a corroded area of a tank 125’ in diameter and 40’ high. Sixteen UT readings are taken every 2” over the length of “L”. The readings are as follows: 0.42, 0.32, 0.38, 0.30, 0.28, 0.25, 0.26, 0.25, 0.23, 0.29, 0.26, 0.31, 0.37, 0.34, 0.33, and 0.39. Determine t1(tavg). Round to the nearest hundredth.
0.31”
The critical zone for repairs to tank bottoms is that portion of the bottom or annular plate within ______ of the inside edge of the shell, measured radially inward.
3”s
Two methods of quantifying the remaining thickness of tank bottoms are mentioned in API 653. One method uses the formula involving “MRT”. What is the name of the other method?
Probabilistic and Deterministic
What is the maximum out-of-plumbness allowed from the top of the shell to the bottom of the shell on a 48’ high tank?
5.00”
Due to strength requirements, the minimum thickness of an annular plate ring is usually greater than:
0.100”
The joint between the new material of an insert plate and the old material of the existing tank shell plate shall be:
Butt welded
A pressure test at least 1.5 times the __________ shall be performed on a nozzle installed by hot tapping after the valve has been installed on it and prior to mounting the hot tap machine.
Hydrostatic head
Cone roof storage tanks may be as large as ______ feet in diameter.
300’
The simplest type of floating roof is the:
Pan
An oxygen deficient atmosphere exists when a tank atmosphere has less than what percent oxygen by volume?
19.5%
Lead-in-Air analyzers must be designed to measure _______ Lead-in-Air concentrations.
Organic
Entry into a confined space is considered to have occurred as soon as:
A part of the entrant’s body breaks the plane of an opening into the space.
When repairs involve most of the tank bottom, it may be desirable to displace the flammable liquids beneath the tank by:
Water flooding
Tank surfaces that have been in contact with leaded gasoline should be scraped down to bare metal. On each side of a line that might be heated excessively by welding or other operations, an area of at least ______ should be scraped down to bare metal.
12”