Questions and Answers
What is the minimum size for telltale vent holes in reinforcing pads?
Where should telltale holes be located in reinforcing pads for accessibility?
What should be used to plug telltale holes in external welded attachments?
What is required for the two segments of a split reinforcing pad?
Signup and view all the answers
What size drain hole is specified for pass partition plates?
Signup and view all the answers
What is the requirement for how nozzles should be finishing on the inside of the exchanger?
Signup and view all the answers
What distance should the center of the telltale hole be from the edge of the pad in attachments other than nozzles and manways?
Signup and view all the answers
What is the next planned update date for the Shell and Tube Heat Exchanger standards?
Signup and view all the answers
What should be done if production test coupons require multiple thermal heat treatment cycles?
Signup and view all the answers
Which tubes require stress relief heat treatment after cold forming and bending?
Signup and view all the answers
Which type of tubes is required to undergo solution annealing?
Signup and view all the answers
When is postweld heat treatment (PWHT) required?
Signup and view all the answers
What is stated about code exemptions for postweld heat treatment of ferritic materials?
Signup and view all the answers
Which of the following statements regarding U bends is accurate?
Signup and view all the answers
Which materials are exempt from the requirement of postweld heat treatment, based on their electrode type?
Signup and view all the answers
What is the minimum length of straight portion that must be considered for heat treatment of U bends?
Signup and view all the answers
Which environments do not permit code exemptions for postweld heat treatment of P4 and P5 materials?
Signup and view all the answers
What is the maximum post weld heat treatment soaking temperature for carbon steel?
Signup and view all the answers
What should be done after completing all welding and repairs, before hydrotesting?
Signup and view all the answers
What is the proper sign that must be displayed on postweld heat treated exchangers?
Signup and view all the answers
For Cr-Mo materials, what is required if alternative tempering and PWHT temperatures are to be used?
Signup and view all the answers
What is the holding temperature range for post weld heat treatment for carbon steel exchangers?
Signup and view all the answers
Which of the following is NOT a condition that prohibits code exemptions for postweld heat treatment of P4 and P5 materials?
Signup and view all the answers
What specification must postweld heat treatment comply with?
Signup and view all the answers
What is prohibited for weld joint categories A, B, C, and D in shell and tube heat exchangers?
Signup and view all the answers
What percentage of qualification time is required for welding procedures that mandate impact tests?
Signup and view all the answers
What type of tests must production test coupons undergo after welding, according to the specification?
Signup and view all the answers
What should production test coupons simulate during hot forming?
Signup and view all the answers
In addition to standard requirements, what extra tests are needed for exchangers in sour service?
Signup and view all the answers
Which standards must hardness testing comply with for sour service exchangers?
Signup and view all the answers
Which document outlines the rules for the exclusion of dissimilar metal welds?
Signup and view all the answers
What is a consequence of improper compliance with the impact testing requirements?
Signup and view all the answers
What factors must the Exchanger Manufacturer consider for ensuring structural stability during PWHT?
Signup and view all the answers
Which of the following tolerances must be adhered to according to the document?
Signup and view all the answers
What is prohibited when components do not meet fabrication tolerances?
Signup and view all the answers
What is the required surface roughness for non-metallic gaskets?
Signup and view all the answers
At what surface roughness should spiral wound gaskets in hydrogen service be manufactured?
Signup and view all the answers
Which statement regarding mechanical restraints during PWHT is correct?
Signup and view all the answers
What is the applicable surface roughness for the side-walls of ring joint flanges in any service?
Signup and view all the answers
What must be considered in determining the dead weight at intended PWHT soaking temperature?
Signup and view all the answers
Study Notes
Telltale Holes in Reinforcing Pads
- Telltale vent holes of ¼ inch should be drilled in reinforcing pads for welded attachments, including nozzles and manways.
- Single piece reinforcing pads require one hole; split pads need at least one hole per segment.
- Holes should be located at the lowest accessible position, 25 mm from the edge of the pad.
- Telltale holes in external pads must be plugged with grease suitable for operating temperatures without retaining pressure; internal pads should be seal welded.
- Split reinforcing pad segments must be welded together without backing strips.
Pass Partition Plates
- Pass partition plates are required to have a 6 mm (¼ inch) drain hole for effective drainage.
Connection Junctions
- Nozzles must be ground flush with the inside curvature of the exchanger's inner diameter, with a smooth corner radius matching the nozzle wall thickness.
Welding Standards
- Dissimilar metal welding is prohibited in specified joint categories if using API RP 934 standards.
- Welding procedures for services requiring impact tests must be qualified with 80% consideration for any subsequent heat treatment.
- Production test coupons need to reflect all heat treatment cycles expected for the manufacturing process.
Heat Treatment Protocols
- Stress relief treatment is mandatory for carbon steel tubes in specific service conditions after cold forming.
- Solution annealing required for specific stainless steels and Nickel base alloys after forming.
- Postweld heat treatment (PWHT) is obligatory when dictated by the applicable Code or data sheets.
- Exemptions for PWHT of ferritic materials using austenitic electrodes are not allowed in sulfide stress cracking environments.
Maximum Temperatures for Heat Treatment
- Maximum PWHT soaking temperatures:
- 650°C for carbon steel
- 700°C for low alloy steels
- Final PWHT must occur after welding and repairs, before any hydrotest.
PWHT Notification
- A visible caution sign must be placed on postweld heat treated exchangers indicating the heat treatment status.
Dimensional Tolerances
- Fabrication tolerances must align with the most stringent requirements from applicable Codes, TEMA, and PIP doc VEFV1100.
- Use of fitness-for-service assessments to qualify designs that don't meet these tolerances is prohibited.
Gasket Contact Surface Requirements
- For spiral wound gaskets, surface roughness should range from 125 to 250 AARH, except for hydrogen service, which requires 125 to 150 AARH.
- Ring joint flanges should maintain a 63 AARH roughness in all services.
- Non-metallic gaskets must comply with a surface roughness of 250 to 500 AARH.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz focuses on the standards established by the Heat Transfer Equipment Standards Committee, specifically addressing the manufacture of shell and tube heat exchangers and details about telltale holes in reinforcing pads. Test your understanding of the key specifications and regulations outlined in the document.