API publications necessarily address problems of a general nature. With respect to partic- ular circumstances, local, state, and federal laws and regulations. API Standard Tank Inspection, Repair, Alteration, and Reconstruction. FIFTH EDITION | NOVEMBER | PAGES | $ | PRODUCT NO. C everyday working knowledge of API Standard and the applicable reference API Standard , Tank Inspection, Repair, Alteration, and Reconstruction.
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API Tank Inspections. Why Inspect Your Tanks? • Prevent leaks into your secondary containment or to groundwater (if you do not have a secondary. API is a standard that covers the inspection, repair, alteration, and reconstruction of aboveground storage tanks. Nov 1, Printed Edition + PDF;; Immediate download; $; Add to Cart API December Tank Inspection, Repair, Alteration, and.
Butt 5b 0. The following list gives some historical causes of tank bot- "All butt joints listed have butt straps both inside and outside. Internal pitting and pitting rates in the anticipated service. Corrosion of weld joints weld and heat affected zone. Weld joint cracking history. The condition of the tank shell welds shall be evaluated for d. Stresses placed on the bottom plates by roof support loads suitability for service.
Any deterioration of the existing welds and shell settlement. Underside corrosion normally in the form of pitting. Inadequate drainage resulting in surface water flowing as necessary.
Some typical shell butt-weld flaws and recom- under the tank bottom. The lack of an annular plate ring when required. Uneven settlement that results in high localized stresses in 4. Roof support columns or other supports welded to the tank tions nozzles, manways, c1eanout openings, etc. Details such as type and extent of reinforcement, weld j.
Rock or gravel foundation pads with inadequately filled-in spacing, and thickness of components reinforcing plate, noz- surface voids. Nonhomogeneous fill under the tank bottom for example, siderations and shall be reviewed for structural adequacy and a lump of clay in a sand foundation pad. Any noncompli- I. Inadequately supported sumps. A selection basis for cathodic protection systems for the underside of tank bottoms is covered by API RP Each aspect of corrosion phenomena, and other readily observed from the outside of the tank.
The methods vary to the extent by StP r maximum rate of corrosion not repaired on the which they can reliably measure general corrosion and pitting. Magnetic flux leakage MFL tools are commonly used, along with ultrasonic UT maximum rate of corrosion on the bottom 03 thickness measurement tools, to examine tank bottoms.
Ultra- side. To calculate the corrosion rate, use the sonic thickness measurement techniques are often used to minimum remaining thickness after repairs. The quality of data cathodic protection. For areas of a bottom that have been scanned by the magnetic flux leakage or exclusion process, Appendix G may be used to provide guidance in qualifying and do not have effective cathodic protection, the personnel and procedures for obtaining thickness data.
The M FL threshold is defined as the minimum remaining Quantifying the minimum remaining thickness of tank bot- thickness to be detected in the areas inspected.
This toms based on the results of measurement can be done by the value should be predetermined by the tank owner method outlined in 4. Other approaches such as the based on the desired inspection interval. Areas of bottom side corrosion that are repaired should be evaluated with the corrosion rate for the 4.
The evaluation is done by using the corro- thereof is as follows: Corrosion of the bottom plate includes loss of metal from iso- where lated or general corrosion. MRT mllllmum remaining thickness at the end of 4. The term RPS refers to the suite of API standards that are designed interval to the next internal inspection shortened.
These are: If a decision is made to replace an existing bottom, API supports the tom plate thickness not including the original corrosion evaluation of installing an RPB or continued use of an RPS. The evaluation allowance or 50 percent of tmill of the lower shell course per should consider the effectiveness of RPS controls, the product stored, the location of the tank, and environmental sensitivities.
An RPB includes steel 4. Isolated pitting will not appre- bottoms, synthetic materials, clay liners, and all other barriers or combina- ciably affect the strength of the plate. The projection 1. The thicknesses specified in the table are based on the founda- tion providing a unifonn support under the full width of the annular thickness of annular plate ring is usually greater than 0. Unless the foundation is properly compacted, particularly at in. Isolated pitting will not appreciably affect the strength the inside of a concrete ringwall, settlement will produce additional of the plate.
Unless a stress analysis is performed, the annu- stresses in the annular plate. During intermediate cooling periods, the con- mic loading considerations, the thickness of the annular crete can absorb moisture, swell, lose its strength, and crack. Deterioration of concrete exposed to underground water plus any specified corrosion allowance.
Sulfate-type alkalies, and to a lesser extent, chlorides, can 4. Temperature cracks hairline cracks of unifoml width do in accordance with the requirements of the applicable standard, not seriously affect the strength of the concrete foundation using the actual thickness of the existing annular plate. To ensure shall be repaired to prevent water from entering the concrete suitability for service, all tank foundations shall be inspected structure and corroding the reinforcing steel.
Distortion of anchor bolts and excessive cracking of the concrete structures in which they are embedded may be indi- a. Calcining loss of water of hydration can occur when con- cations of either serious foundation settlement or a tank over- crete has been exposed to sufficiently high temperature for a pressure uplift condition.
These tanks are potentially existing tanks for suitability for continued operation or susceptible to failure due to brittle fracture and require an change of service with respect to the risk of brittle fracture assessment as illustrated by the decision tree.
The procedure applies to both welded ing demonstrates that an aboveground atmospheric storage and riveted tanks; however, the procedure is based primarily tank in a petroleum or chemical service is fit for continued on experience and data obtained from welded tanks. The decision tion.
The effectiveness of the hydrostatic test in demon- tree is based on the following principles: This experience shows that once a tank has demon- with Section 4 has been performed. The original nominal strated the ability to withstand the combined effects of thickness for the thickest tank shell plate shall be used for maximum liquid level highest stresses and lowest operating this assessment. Simi- 5. In ing the metal temperature by heating the tank contents.
The following aspects should be considered: Deterioration of the tank since original hydrostatic test. Tanks fabricated from steels of unknown toughness 5. The original nominal thickness for thickest tank be used for evaluating aboveground atmospheric storage shell plate shall be used for the assessment.
For unheated tanks in petroleum and chemical services. Each of the key tanks, the shell metal temperature shall be the design metal steps, numbered 1 through I I on the decision tree, corre- temperature as defined in API Std , 2. Tanks may also be shown to meet the toughness without failing.
For the purpose of this assessment, the lowest requirements of API Std seventh edition or later by expected temperature is defined as the lowest I-day mean impact testing coupon samples from a representative number temperature as shown in Figure of API Std It is nec- of shell plates.
This does notO exempt tanks from otherO Yes hydrotest requiremcntsO stipulated in this standard. E Safe for use. El roQ 30 E Qi. For unheated tanks, the shell metal temperature shall equal the design metal temperature as defined in 2.
The original nominal thickness for the thickest tank shell plate shall be used for the assessment. The procedures and accep- 5. This evaluation shall be based on the most severe combina- tion of temperature and liquid level experienced by the tank 5.
The evaluation may show that the tank needs to made in compliance with this standard. Restrict the liquid level. The service can be considered more severe b. Restrict the minimum metal temperature. Change the service to a stored product with a lower spe- ature is reduced for example, changing from heated oil service cific gravity. Combinations of a, b, and c, above. Personnel performing this inspection should as defined herein.
The purpose of this inspection is to assure be knowledgeable of the storage facility operations, the tank, continued tank integrity. Inspections, other than those defined and the characteristics of the product stored. These include, but are 6. Evidence of leaks; shell distortions; signs of settlement; corrosion; and a. The nature of the product stored. The results of visual maintenance checks. Corrosion allowances and corrosion rates.
Corrosion prevention systems. Conditions at previous inspections. The methods and materials of construction and repair. The location of tanks, such as those in isolated or high risk 6.
This inspection shall be called the h. The potential risk of air or water pollution. Leak detection systems. Change in operating mode for example: Tanks may be in operation during this k. Jurisdictional requirements. Changes in service including changes in water bottoms.
The existence of a double bottom or a release prevention 6. A history of the service of a given tank or a checked. Recommended practices dealing with the preven- tank in similar service preferably at the same site should be tion of hydrocarbon ignition are covered by API RP These regulations indication of the integrity of the shell. Knowledge of such reg- 6. When the corrosion rate is not known, the maximum inter- 6. Corrosion rates may be estimated from TANK tanks in similar service based on thickness measurements taken at an interval not exceeding 5 years.
When the corrosion rate is known, the maximum interval 6. Normally, bottom corrosion rates will control interval is equal to or less than the interval required in and the inspection interval will be governed by the measured 6. The 6. The shall the internal inspection interval exceed 20 years. Ensure that the bottom is not severely corroded and based inspection RBI procedures.
Combining the assess- leaking. Gather the data necessary for the minimum bottom and sequence of tank leakage or failure is the essential element of shell thickness assessments detailed in Section 6. As applica- RBI. A RBI assessment may increase or decrease the internal ble, these data shall also take into account external ultrasonic inspection intervals obtained using the procedures of 6.
Identify and evaluate any tank bottom settlement. The RBI assessment may also increase or decrease the year inspec- 6. The initial RBI assessment conducted at the intervals defined by 6. The shall be reviewed and approved by an authorized inspector authorized inspector who is responsible for evaluation of a and an engineer s , knowledgeable and experienced in tank tank must conduct a visual inspection and assure the quality design including tank foundations and corrosion.
If the internal inspec- assessment shall be subsequently reviewed and approved by tion is required solely for the purpose of determining the con- an authorized inspector and an engineer s , knowledgeable dition and integrity of the tank bottom, the internal inspection and experienced in tank design including tank foundations may be accomplished with the tank in-service utilizing vari- and corrosion, at intervals not to exceed 10 years, or more ous ultrasonic robotic thickness measurement and other on- often if warranted by changes in service.
Electro- assessment of a tank include the following: The material of construction, including liners and coat- ultrasonic inspection. If an in-service inspection is selected, ings, relative to the product temperature and ambient the data and information collected shall be sufficient to evalu- conditions.
The design codes or standards utilized in the tank con- tank bottom thickness, corrosion rate, and integrity, utilizing struction and repair including tank bottoms.
An individual, knowl- c. The methods used for determination of the shell and bot- edgeable and experienced in relevant inspection methodolo- tom plate thickness.
The availability and effectiveness of the inspection meth- of the in-service NDE results. This alternative approach in. Foundation Design shall be documented and made part of the pennanent record of the tank. API RP The analysis methods used to detennine the product side, soil side, and external corrosion rates and the accuracy of 6. The availability, accuracy, and need for leak detection 6. Inspection records form the basis of a scheduled inspec- g.
It is recognized that records may cathodic protection systems, liners, and coatings. The quality of the maintenance, including previous experience with tanks in similar services.
The probability of and type of failure, i. The environmental consequence and likelihood of a tank 6.
Construction records may include nameplate information, Historic tank leakage and failure data and infonnation will drawings, specifications, construction completion report, and also be important for this assessment. It is essential that all RBI assessments be conducted by trained, qualified individuals knowledgeable in RBI method- 6.
RBI assessments The inspection history includes all measurements taken, shall be thoroughly documented, clearly defining all the fac- the condition of all parts inspected, and a record of all tors contributing to both the likelihood and consequence of examinations and tests.
A complete description of any tank leakage or failure.
These records should include the external access to the tank bottom to detennine bottom thick- results of any experiences with coatings and linings. The results of any 6. Specific requirements for repairs and alter- 7. Existing rolled structural shapes that are to be reused 7. New structural material shall meet the requirements of All new materials used for repair, alterations, or recon- ASTM A 36 or A as a minimum.
Materials identified by original contract drawings, API name plates, or other suitable docu- 7. Material not the current applicable standard. After identification, determination shall be 7. If existing plates are to be used to reconstruct the tank, they 7. See tion does not exist shall be subjected to chemical analysis and Sections 4 and 6. Impact values shall satisfy the require- 7.
When the direction of rolling is not Welding consumables shall conform to the AWS5 classifi- definitely known, two tension specimens shall be taken at right cation that is applicable to the intended use.
Lejeune Road, Miami, plates welded to the shell shall meet, as a minimum, the Florida , www. If the actual thickness is greater than that necessary to allow the liquid level required, the extra Any specific design considerations other than normal prod- thickness can be considered as corrosion allowance. The joint efficiency and allowable stress levels for existing welded joints that are not 8.
See 4. For 8. Reconstructed tanks shall be built to meet the stability 8. Thickened bottom structed tank, the required corrosion allowance shall be plates under the bottom shell course or anchoring of the tank deducted from the actual thickness before calculating the may be required even if not used on the original tank.
Std equivalence. The replacement plate may be cir- rized inspector or an engineer experienced in storage tank cular, oblong, square with rounded comers, or rectangular design, before commencement of the work by a repair orga- with rounded comers except when an entire shell plate is nization.
Authorization for alterations to storage tanks that replaced. Refer to Figure for typical details of acceptable comply with API Std may not be given without prior replacement shell plates. The authorized inspector will segments of shell plates are to be removed and replaced, the designate inspection hold points required during the repair minimum spacing requirements specified in Figure for or alteration sequence and minimum documentation to be vertical weld joints shall be maintained.
It is acceptable to submitted upon job completion. The authorized inspector remove and replace entire shell plates or full height segments may give prior general authorization for limited or routine 01 of shell plates by cutting and rewelding along the existing hor- repairs as long as the authorized inspector is sure that the izontal weld joints.
Prior to welding the new vertical joints, repairs will not require hydrostatic testing or do not require the existing horizontal welds shall be cut for a minimum dis- an engineering evaluation. The vertical 9. The autho- 9. Joints in lap-welded shell tanks may be repaired according to 9. Lap-welded joint design of examination and provides the acceptance standards, exam- for lapped patch shell repairs shall meet the requirements of 01 iner qualifications, and procedure requirements.
Appendix F 9. Details of welding shall be in accordance with 5. The spe- cific requirements as listed in Sections I through 12 shall be 9. See Plate Figure for minimum dimensions. The thickness of the replacement shell plate be at least the greater of 8 times the weld size or lOin. For shell PLATES plates of unknown toughness not meeting the exemption cri- teria of Figure , the edge of any vertical weld joint 9.
Figure has 9. In addition, the minimum dimensions. These repairs are permanent repairs sub- 9. Greater of 6 in. Greater of 10 in. Greater of 12 in. Prior to welding new vertical joints.
Weld the horizontal joint last. Prior to welding new vertical joints, cut existing shell-to-bottom weld for a minimum of 12 in.
The cut shall extend past or stop short of existing bottom plate welds by at least 3 in. Weld the shell-to-bottom weld last. All comers, except at the shell- to-bottom joint, shall be rounded to a minimum radius of 2 in. The nozzle reinforcing plate shapes of API Std are also acceptable.
The plate to clear weld spacing requirements of Figure shall be used as a shell-to-bottom basis for locating repair plates relative to butt-welded, fillet- weld welded, and riveted seams and other repair plates. Detail A Detail B 9. Figure Lapped Patch Repair Plates at the 9. The mini- 01 I mum repair plate dimension is 4 in.
The repair plate shall be formed to the shell radius. The welds of the repair plate shall be full fillet 9. The minimum repair plate dimension shall be 4 in. In addi- 01 I tion, the following requirements shall be satisfied.
The minimum hole diameter is 2 in. Lapped patch repair plates may also be used for shell plates Shell openings due to plate removal shall have a minimum that are below the retirement thickness, providing the follow- comer radius of 2 in. The perimeter weld shall be a full fillet weld.
The modified shell severely isolated or widely scattered pitting if the following height shall be in accordance with the requirements of the requirements are satisfied. However, if operating conditions are such that the exces- the fillet welds to the product will produce crevice corrosion sive weld reinforcement may be deleterious such as for a or if a corrosion cell between the shell plate and repair plate is floating roof with flexible seals , consideration shall be given likely to occur.
If the existing shell plate thickness 9. Arc strikes 9. The reinforcing be determined on an individual case basis in accordance with plate shall meet all dimensional and weld spacing require- Section 4.
In areas where the shell plate thickness exceeds ments of API Std See Figures A and for accept- that required by design conditions, it is permissible to grind able details. Tor t 1. All details, dimensions, and weld spacing shall be in accordanceO c. If an integral reinforcement design is used, the thickness with the requirements of API Std Spacing of welds shall be in accordance with Figure 9-l.
The joint between new material of the insert plate and old material of the existing shell plate shall be butt-welded. All details. Care must be exercised during the trimming operation to Figure Typical Details for Addition of 'Tombstone" avoid damaging the shell material beneath the reinforcing Shape Reinforcing Plate to Existing Shell Penetration plate.
These repairs are penn anent repairs subject to an on-going assemblies. If it is not known whether the assembly was ther- inspection and maintenance program. Care must be 9. The new reinforcing plate shall be in accordance with Figure A. See Figure B. When a welded-on patch plate is within 6 in. The the section of the shell containing the fitting and reinforcing sides of the tombstone shaped welded-on patch plate shall plate, and raising the entire assembly to the correct elevation intersect the shell-to-bottom joint at approximately 90 see Figure Cut lines in shell plate 9.
Refer to Figure for acceptable details for welded-on patch plates. The minimum dimension for a welded-on patch plate that overlaps a bottom seam or existing patch is 12 in. A welded-on patch plate smaller than 12 in. Welded-on patch plates shall not be placed over areas of ,or as permitted per 9. If the tank is still undergoing settlement, the addition of welded-on patch plate may not be advisable.
LOld bottom d. For welded-on patch plates less 12 in. Three-plate lap Cf: Shell plate z j -i: Dimensions given are from toe of fillet welds or to centerline of butt-weld and also apply to new-to-existing welds. Critical Welded-on patch plate 2.
The maximum dimension along the shell for welded-on patch critical zone plates in the critical zone is 24 inches. When the edge ofa welded-on patch plate is approximately parallel to a bottom seam, the edge shall be held at least 2 inches from weld seam.
Patches over three-plate laps shall extend 12 inches minimum beyond the three-plate lap. Bottom plate or annular plate ring 6. These rules apply to butt-welded bottoms, where applicable.
Perimeter welds on welded-on patch plates within the crit- tion. The weld repair of bottom plate corrosion is permitted if ical zone shall be two-pass, minimum, and examined per all of the following conditions are satisfied. The sum of the pit dimensions along an arc parallel to the d. Installation of a welded-on patch plate by butt-welding to shell-to-bottomjoint does not exceed 2 in.
There must be sufficient remaining bottom plate thickness e. Welded-on patch plates over existing patches are not for completion of a sound weld and to avoid bum-through. The minimum acceptable bottom plate thickness for weld f.
The bottom plate under the perimeter of a welded-on patch repairs is 0. A lesser thickness is permitted for weld plate shall meet the thickness requirements in 4. The bottom plate thickness at the attachment weld must be at enced in storage tank design and repair. All weld repairs shall be ground flush with the surround- bottom plate.
The new bottom plate shall be extended outside the 9. All rules for weld spacing the critical zone than those listed in 9. Weld spacing requirements shall be in shall be filled with sand, crushed limestone, grout, or con- accordance with API Std , 3. Std ,9. The review shall consider brittle fracture, 9. For reinforced penetrations, including low types, a mini- 9. Surface irregularities and b.
For self-reinforced penetrations, the greater of 3 in. The shell-to-bottom weld is to be welded with low hydro- 9. The toes of the welds shall be blend-ground to minimize limited to pit welding or overlay welding as noted in this sec- stress concentrations as listed below: Also see 4. Blend-grind the inside and outside of the shell-to-bottom weld a 9. For diamond-shaped reinforcement plates, blend- striker, and bearing plates, are to be added to tank bottoms, grind the lower horizontal length of the diamond- they shall be installed in accordance with 9.
Blend-grind the inside and ined in accordance with For these additional welded- 01 outside of the shell-to-bottom weld a minimum of one on plates, if the lap weld spacing requirements as set forth in penetration diameter length on either side of the pene- Figure are not met, magnetic particle MT or liquid pen- 03 tration's centerline.
For low-type penetrations, blend-grind the nozzle portions of welds failing to meet minimum spacing criteria. Blend-grind the inside and outside of the shell- see 3. The blend-ground lengths of welds listed in 9. In the event roof live loads in excess of in the down position. Removing the entire shell-to-bottom attachment weld, 9.
Sections 3. All arc gouged areas of the tank shell shall be magnetic par- ticle examined, and defective areas repaired and re-examined.
Frangible of the existing tank bottom, shall meet all requirements of joint design, or the need for emergency venting devices in API Std For tanks with shell plate of unknown tough- accordance with API Std , shall meet the requirements of ness that do not meet the exemption criteria of Figure , API Std ,3. If metallic elements, and chemical and weather deterioration the original construction drawings are not available, the roof of seal fabric.
The service life and inspection information repairs shall be in compliance with the requirements of API shall be used to determine whether a change of material is Std , Appendix H. In addition, the final 9. Rim-mounted primary shoe seals and toroidal seal systems can be removed, repaired, or replaced. To minimize evapora- 9. Temporary spacers to keep the roof centered shalI be used during the repairs.
Primary seal 9.
In this case, in-service repairs are limited to replacement heat treatment. For tank shell plates of recognized toughness, shell plates of unknown toughness having a maximum thickness less than 9.
Recognized toughness is defined as meeting or exceeding 9. For tank shell plates of unknown toughness with thickness a. Increasing the length of rim mounted secondary seals in ing limitations apply.
Replacing all or part of the primary seal system along with I. Nozzles shall be limited to a maximum diameter of possible installation of a rim extension for a secondary seal. This step shall be taken only after checking the annular space 2. The shell plate temperature shall be at or above the variation at several levels from low pump out to high liquid minimum shell design metal temperature for the entire hot level.
All nozzles shall be reinforced. The reinforcement shall be calculated per API Std , 3. The minimum Damaged parts shall be repaired or replaced. Prior to tak- thickness of the reinforcing plate shall be equal to the ing this action, the cause of the damage shall be identified and shell plate thickness, and the minimum reinforcing plate corrected. Buckled parts shall be replaced, not straightened. The maximum height of tank liquid above the hot tap 9. The reinforcing plate to nozzle shall be installed 9.
Care shall be taken to limit the trodes. After the valve has been installed on the flange, severely pitted shell plate. A hot tap procedure specific to carrying out the work shall be developed and documented. The procedure shall include the practices given in API Publ Horizontal weld if: If the tank has an existing butt-welded annular ring, this ring can be left attached to the shell or removed from the shell Section Any shell ring may be dismantled by cutting out existing The authorized inspector ever is less, on both sides of the weld seam.
The area where temporary attachments are removed shall be ground flush The tank shall be cleaned and gas-freed prior to com- The existing shell-to-bot- tom weld connection shall not be reused unless the entire bot- Marking material shall be of a a. The bottom plates may be cut from the shell along a line durable type.
Drawings showing piece mark locations are A-A and line B-B shown in Figure , scrapping the welds also a useful adjunct. If the entire bottom is to be reused, the bottom may be cut See When such joints are welded by the submerged-arc process, the tack Figure Tank Shell and Bottom Cut Locations welds shall be thoroughly cleaned of all welding slag but need not be removed provided that they are sound and are thoroughly fused into the subsequently applied weld beads.
Tack welds to be left in place shall be made by quali- All other coatings New vertical joints in adjacent ual metal-arc welds, including the attachment of the first shell shell courses, made in accordance with For all welds in shell courses over II2-in. The the surfaces of the parts to be welded are wet from rain, snow, welding procedure selected shall not cause underbead or ice; when rain or snow is falling on such surfaces; or dur- cracking; also, the need for preheat of thick plates and the ing periods of high winds unless the welder and the work are effect of low atmospheric temperature during welding shall properly shielded.
No welding of any kind shall be performed be considered. Other requirements shall be in accordance with Misalignment in joints SIS-in. Vertical joints shall be completed roof columns.
For tanks with internal floating roofs, apply the before the lower horizontal weld is made. Radius tolerances measured higher than one foot above the thick permitted. The sweep board shall be made to the true such as rafters and girders must be reasonably true to line outside radius of the tank.
The foundation shall be determined from the actual elevation of the specified have adequate bearing capacity to maintain the trueness of the high point.
The actual elevation differences shall not deviate foundation. If the material specification for the steel from an exist- And the rest of the members check the API answers turn-by-turn. Only then we publish the API answers. So, no one can falter the accuracy of our Aboveground Storage Tank Inspector answers. It opens on all devices conveniently. Get access to the dump as soon as you send the payment.
Furthermore, the users get 90 days free updates. It has a few API questions solved. Safe and Secure Our website is safe and secure for its visitors. You can check out with Bit SSL encryption. What is the Square Root of ? What is the radius of a circle whose diameter is '? What is the area of the circle in Question 7? Solve for Z: An inspection is performed on an existing AST 67' tall. What is the minimum thickness of the first course.
What is the minimum thickness of the fourth course of the tank in question What is the design first course thickness of a new tank that is 60' tall. What is the annular plate thickness of the new tank in question What is the hydrostatic test first course thickness of the new tank in question 18?
What is the minimum thickness of the first course of an existing tank if the nameplate reads as follows: A Specific Gravity: Use the formula.
Answers will be discussed at the beginning of class the following morning.. The following is a collection of questions remembered by various students who took the API Exam in the past. API Practice Exam. Section QW only B Beeggiinn tthhee ooppeenn bbooookk ppoorrttiioonn ooff tthhiiss eexxaam m oonn tthhee nneexxtt ppaaggee. Welding in the 3G position qualifies a welder in what positions? Flat and horizontal Horizontal and vertical Flat and vertical Vertical and overhead A change in groove design A change in backing A change in post weld heat treatment A change in electrode angle A welder may be qualified by RT if 1.
The liquid penetrant examination method is an effective means for detecting 1. Welders shall be qualified in accordance with 1. Geometric unsharpness of the radiograph of a component under 2" thick shall not exceed. What is the maximum allowable prod spacing using an AC prod technique? Based on the above information should a repair be made? Ultrasonic examination of hot tap connections or reinforcement is required by API when.
The required thickness of the shell in this area is 0. What is the maximum permissible height for the bulge? Calculate the minimum thickness for the third course. Assume pit depth of one-half of the minimum acceptable tank shell thickness. N Noottee:: Assume pit depth of slightly less than one-half of the minimum acceptable tank shell thickness. Because the pits are aligned vertically no repair is required Scattered pits may be ignored If the pit is round.
Calculate the minimum thickness of the first course based on product alone. There is one area of general internal corrosion on the south side of the shell 20" wide and 20" in vertical length.
The pits measure. The diameter of the pits are 1. There is evidence of bottom settlement. TThhee ffoolllloow w:: What is the hydrostatic test height of this tank based on a minimum thickness found in question An area of edge settlement in the tank bottom 6' from the shell has sloped down and settled.
A more rigorous stress analysis must be performed The area should be repaired Sloped edge settlement is usually no problem The area should be documented and checked during the next inspection Yes No Not enough information given The tank holds water. Should a repair be recommended? The settlement measures 2" at the deepest point. The bottom lap welds are approximately parallel to the shell.
Using data from above. Grade 70 A M Grade The material of construction is A A DC yoke shall have a lifting power of at least 1. Weld build-up the area. Hydrostatic test stress Does the procedure need to be requalified? A new tank will hold a product with the specific gravity of 1. Use RBI. What is the thickness required for the annular plate? Include corrosion allowance. What type of repair. When using the SMAW process. The thickness of the first course is 1.
Because the product might not contaminate the soil or waterways. During an MT examination. The corrosion allowance is. Floating roofs on new tanks shall be sufficiently buoyant to remain floating after 1. Fifteen inches of rainfall in a hour period Ten inches of rainfall in a hour period Thirty inches of snow in a hour period Thirty inches of sand in a hour period A sudden rapid fracture under stress.
The shell material is A 36M. During a welder qualification test. If the supporting PQR is used. Each floor scanning operator. SFA 5. Section IX. Weld Symbols or Written Description should show the general arrangement of the parts to be welded. Production Drawings.. Class E F-No. Analysis and Mech. Where applicable. Welding Process es: SMAW Type s: P 1 Date: Thickness Range: Base Metal: This information may be listed in a tabular form similar to that shown below.
Torch Angle. Interpass Temp. Hot Wire Addition.. Spray arc. Procedure Qualification Record No. Width 1 Impact Values Lateral Exp SIGNED Detail of record of tests are illustrative only and may be modified to conform to the type and number of test required by the Code Tests conducted by: Laboratory Test No API Practice Exam JP We certify that the statements in this record are correct and that the test welds were prepared Please close all materials. TThhee sseeccoonndd ppaarrtt ooff tthhee eexxaam Booookk.
Who has the ultimate responsibility for complying with the provisions of API Standard ? If cracks are suspected in nozzles or nozzle welds they should be checked by. Every 10 years Every time the tank is empty Annually Semi-annually During the reconstruction of a tank. On a fixed-type roof. How often should this survey be done?