653 - 1 Flashcards by Egal Adam

Stage 1: Code permitted Minimum Design Metal Temperature (by material) – This stage involves two
steps: What is Step 1

Identify the Material Group for the plate to be used, using Table 4.4b. API 650

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Stage 1: Code permitted Minimum Design Metal Temperature (by material) – This stage involves two
steps: What is Step 2

Using Figure 4.1b API 650, determine the Minimum Design Metal Temperature (MDMT) for that
material.

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Stage 2: Determining Design Metal Temperature by Location – This stage also has two steps: What is step 1

Using Figure 4.2, determine the Lowest One-Day Mean Temperature.

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Stage 2: Determining Design Metal Temperature by Location – This stage also has two steps: What is step 2

Add 15°F to Lowest One-Day Mean temperature found in step 1 as described in paragraph 3.8.

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How can we determine whether a material needs to be impact
tested or not.

If the Design Metal Temperature by Location +15 degrees is higher than the Code permitted MDMT (by material) impact testing is not required. If the Design Metal Temperature by Location +15 degrees is at or below the Code permitted MDMT (by material) then impact testing is required.

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Navigation in API 650 - Name the section/chapter - Material requirements.

Section 4

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Navigation in API 650 - Name the section/chapter - Design calculations and minimum thicknesses.

Section 5

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Navigation in API 650 - Name the section/chapter - Rolling and fabrication rules.

Section 6

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Navigation in API 650 - Name the section/chapter - Onsite construction requirements

Section 7

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Navigation in API 650 - Name the section/chapter - NDE rules

Section 8

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Navigation in API 650 - Name the section/chapter - Bottom foundation requirements

Annex B

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The required thickness of a tank shell shall be the greater of:

the calculated design thickness using product stress formula
the calculated hydrostatic stress thickness
the minimum required thickness from paragraph 5.6.1.1

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What is the below formula used to determine.

       2.6D(H-1)G Td = \_\_\_\_\_\_\_\_\_\_\_\_\_ + CA
               Sd

Design Shell Thickness Formula

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What is the below formula used to determine.

       2.6D(H-1) Tt = \_\_\_\_\_\_\_\_\_\_\_\_\_ 
               St

hydrostatic test shell thickness

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What is the below formula used to determine.

           2.6D(H-1)DG Tmin = \_\_\_\_\_\_\_\_\_\_\_\_\_ 
               SE

For determining the minimum thickness of an entire shell course

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What is the below formula used to determine.

           2.6HDG Tmin = \_\_\_\_\_\_\_\_\_\_\_\_\_ 
               SE

For determining the minimum acceptable thickness of a locally thinned area

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What is nomenclature for the formula used to determine.

           RT- MRT Or = \_\_\_\_\_\_\_\_\_\_\_\_\_ 
           StPr+UPr

RT = remaining thickness
MRT = minimum remaining thickness (taken from Table 4.4)
StPr = topside corrosion rate
UPr = underside corrosion rate

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In a product fill height calculation, the stress will be on the material for the rest of the interval until
the next scheduled inspection, so the value of tmin to use in the formula is:

tmin in product fill height calculation = tmin – (Interval x Corrosion rate)

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In a hydrostatic test height, the stress on the material is only for one day, so the value of tmin to use in the formula is:

The current
value of tmin or actual thickness

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When calculating the value to be used for “H” in a product fill height or hydrotest formula, what do the formulas only solve for.

Formulas only solve for the height of water or product above the area
of interest.

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On API 571 what is the way to solve pretty much every damage mechanism.

Through Design

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What should you consider if you
get asked a question about how to mitigate or prevent a damage mechanism.

Design

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When we consider corrosion damage to materials, what is the worst to best in regards to corrosion resistance.

a. Carbon steel is the worst material for corrosion resistance
b. Austenitic stainless steel (300 series SS) is better
c. Duplex stainless is very good
d. Nickel is the best material for corrosion resistance.

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The most likely critical factors for all
corrosion mechanisms include

a. Temperature - everything gets worse when it gets hotter
b. Velocity - everything is damaged more when the velocity is higher
c. Oxygen concentration - almost all corrosion becomes worse when the oxygen
content is increased

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The most likely critical factors for acid corrosion mechanisms include

a. Acid concentration b. Temperature c. Velocity

Identify what NDE to use - Fatigue, all types of stress corrosion cracking, CUI, corrosion and erosion- that are present with surface breaking indications

Use MT or PT as your first choice depending on the material

Identify what NDE to use - HIC, SOHIC

Use volumetric NDE to see "inside" the material to where the hydrogen bubbles are forming and cracking

Identify what NDE to use -Metallurgical changes - graphitization, carburization

Metallographic replication and lab analysis to identify

What are the following paragraphs pertaining to in ASME Section IX - QW-200

WPS & PQR Development

What are the following paragraphs pertaining to in ASME Section IX - QW-300

Performance Qualification

What are the following paragraphs pertaining to in ASME Section IX - QW-152, QW-153

Tension test procedure and acceptance criteria.

What are the following paragraphs pertaining to in ASME Section IX - QW-162, QW-163

Bend test procedure and acceptance criteria.

What are the following paragraphs pertaining to in ASME Section IX - QW-253

SMAW procedure development variables.

The WPS requires what variables on the WPS

All essential and non-essential variables on the WPS

The PQR requires what variables on the WPS

essential variables only are required on the PQR.

What is the following table pertaining to in ASME Section IX - Table QW-416

Comparison between welding processes of the essential performance qualification variables.

What are the following paragraphs pertaining to in ASME Section IX - QW-353

SMAW performance qualification variables.

What is the following table pertaining to in ASME Section IX - Table QW-451.1

Procedure qualification limits and type and number of tests required.

What is footnote 1. pertaining to in ASME Section IX - Table QW-451.1

Three variables in footnote 1 – ½”pass rule, less than ½” GMAW-S rule for both base metal and weld metal

What is the following tables pertaining to in ASME Section IX - Tables QW-452.1(a), (b), Table QW-452.3, Table QW-461.9

Performance qualification only. Four tables to determine number of tests, thickness qualified, size qualified and positions qualified.

Tank Grades – The grade or surface that a tank will rest on SHOULD be constructed at

SHOULD be 1 foot above surrounding grade

Tank Grades – The grade or surface that a tank will rest on SHALL be constructed at

SHALL be a minimum of 6 inches after settlement.

What is the recommended final layer under the tank bottom

Clean washed sand 3 to 4 inches deep.

Tank shall be crowned (sloped) at a ration of

1:120 inches (1 inch in 10 feet)

Concrete ringwalls shall be how thick?

Not less than 12 inches thick

Concrete ring walls shall be located at least where?

2 feet below the lowest adjacent finished grade.

Bottom plates shall have a corroded thickness of not less than

.236"

How many inches of the bottom plate shall project past the shell

At least 2 Inches or the projection shall allow ½ inch from the toe of the shell-to-bottom fillet to the edge of the projection – whichever is greater.

Three plate laps in the bottom plates of a tank shall be at what distance to each other

at least 12 inches from each other, the tank shell, and from joints between the annular plates and the bottom.

Required thickness of a tank shell SHALL be what?

The greater of the design shell thickness – INCLUDING corrosion allowance – or the hydrostatic test shell thickness, but not less than what is shown in 5.6.1.1

Vertical shell joints shall be offset by?

At least 5t where t is the thickness of the thicker plate at the point of offset

Shell-to-bottom fillet weld sizes

Not more than ½ inch, and not less than the nominal thickness of the thinner of either the shell plate or the bottom plate, but not less than the minimums in the table in API 650 5.1.5.7 a)

Roof plate thickness shall not be less than

3/16 inch (or 7-gauge sheet) plus any applicable corrosion allowance.

Maximum top angle weld on a frangible roof is

3/16 inch welded on the top side only.

Floating roof deck plates shall have a minimum nominal thickness of

3/16 inch.

Sleeves and fittings used on floating roof decks shall have a minimum wall thickness of

¼ inch for all pipe and plate construction

Floating roofs shall be able to withstand a

10-inch rainfall in a 24-hour period with the primary drains inoperative.

Primary roof drains shall be not smaller than NPS 3 if the tank is

If the tank is less than 120 feet in diameter, and not smaller than NPS 4 for roofs with a diameter greater than 120 feet.

Roof support legs shall have at least two settings –

High roof clearance of 78 inches and a minimum clearance for tank internals of 3 inches.

Floating roof penetrations shall have a seal that will permit what?

A local deviation in travel of ±5 inches.

Minimum size of fillet welds shall be as follows - Plates 3/16 inch thick the weld shall ?

Full thickness fillet weld

Minimum size of fillet welds shall be as follows - Plates more than 3/16 inch thick the weld thickness shall -

Not be less than one-third the thickness of the thinner plate and shall be at least 3/16 in.

Routine in-service inspection is completed at what intervals

At intervals consistent with the conditions on-site but shall not exceed 1 month

Routine in-service inspections can be completed by who?

Can be done by owner/operator personnel

Visual external inspection shall be completed at what interval?

Every 5 years or RCA/4N – whichever is less.

UT thickness inspection where the corrosion rate is not known shall be competed when?

Every 5 years if the owner/operator has decided to use this method.

UT thickness inspection where the corrosion rate is known shall be completed when?

The the smaller of RCA/2N or 15 years.

Internal inspection of the shell is an acceptable substitution for external UT thickness inspection if the?

Internal inspection interval is equal to or less than the UT interval.

What is the Internal initial inspection interval

10 years + any safeguards but not more than 20 years if there is no RPB, or no more than 30 years if there is an RPB

What are the types of bottom settlement.

uniform settlement rigid body tilting out-of-plane

Which type of bottom settlement may impede the proper functioning of the floating roof

Out-of-plane settlement

When shall Roof plates be replaced.

When its corroded to less than 0.09 inches in any 100 in.², or any roof plates with holes shall be replaced

Evaluation of the existing tank shell is carried out by who?

An engineer.

Critical length “L” shall not be more than?

40 inches in any situation

The minimum acceptable thickness in any tank shell course shall not be less than

0.1 inch

Criteria for continued operation of a tank shell always includes adding what?

The corrosion allowance to the calculated thickness

Joint efficiency for a welded tank is 1.0 provided the area being considered is what?

More than 1 inch or 2 times the plate thickness.

Joint efficiency for a riveted tank is what

1.0 only when away from the rivets by at least 6 inches

Minimum Remaining Thickness (MRT) at the next inspection for the bottom plate is a minimum of what?

Minimum of 0.10 inches with no lining or means of detection of a leak.

The interval for tank bottom inspection (Or) is calculated using a simple Remaining Life formula which is -

RT (what do you have today) – MRT (minimum value from Table 4.4) divided by the total corrosion rate (add bottom corrosion rate to the topside corrosion rate) RT – MRT / CR = Or

Minimum dimension for a replacement plate is

2 inches or 12 times the thickness of the replacement plate – whichever is greater.

What should you do prior to welding new vertical joints in repair plates.

Cut existing horizontal welds for a minimum of 12 inches beyond the new vertical joints, and weld the new horizontal joints last.

Maximum size of hot tap nozzles in a tank with unknown toughness is what?

NPS 4

Hot tap nozzles shall be made of

Schedule Extra Strong Pipe

There shall be a minimum of how many feet of liquid above the hot tap location.

3 feet of liquid above the hot tap location.

Materials affected by soil corrosion include

Carbon steel, cast iron and ductile iron

Acceptance criteria for radiographs of repair welds on an in service tank

API 650

When examining duplex stainless steel materials using the PT method

All penetrant materials shall be analyzed individually for chlorine and fluorine content

There shall be a minimum of 3 feet of liquid above the hot tap location.

<_ 1/2"

Coating bond failures commonly occur where?

Below seam leaks

Minimum thickness of any shell course being evaluated for suitability for service shall not be less than

.100"

The Maximum weld pass thickness for reconstructed tanks on horizontal and vertical welds in tank shell courses that have material over 1.5" thick shall be

.75"

Preheat zone shall have the temperature raised to the correct preheat temperature within

3" of the place the welding will be started

The concept of endurance limit is primarily applied to -

Smooth Bars (Eg. Pump Shaft)

Use of oxyfuel welding process is not permitted

for tanks that require impact testing

Internal floating roofs shall be repaired in accordance with what Annex if the original drawings are not available.

API 650 Annex H

A lamination can be repaired in plate that shall be used to fabricate a tank provided that it does not exceed

3" Long and 1" in depth

ASME Section IX restricts the use of volumetric NDE for procedure qualifications to which welding process

ALL - Volumetric NDE is not permitted for procedure qualification

How far away from Rivets and seams must an area to be in order to considered as having a joint efficiency of 1.0

What are Acceptable codes that welding procedures for the repair and alteration of tank stairways, handrails and other miscellaneous assemblies

AWS D1.1 ASME Section IX AWS D1.6

Steel in an internal floating roof that is in contact with vapor or liquid shall be a minimum nominal thickness of

3/16"

Maximum undercut allowable by visual examination on vertical butt joint

1/64"

Change of service to operation at elevated temperatures

API650 Annex M

The arc stuf welding process is limited the attachment of studs that are

3/8" Diameter

To ensure the adhesion neccessary for long term performance of a tank liner, the anchor pattern must be

Sharp and Angular

Penetrations larger than NPS4 shall be installed with the use of an insert plate if the shell plate thickness is

>1/2"

Each radiograph shall clearly show a minimum of

6" of weld length

Qualification of stud welding procedures shall involve welding and testing of

10 Studs

Concentration cell corrosion may cause pitting of a bare steel tank bottom at a rate as high as

80 Mils/per year

The minimum size of the letters on a replacement or reconstructed nameplate shall be

5/32"

What is the minimum thickness allowed by api 653 for a new roof rim

3/16"

What is the likely location of oxygen cell corrosion

under a surface deposit

653 - 1 Flashcards

(113 cards)