Heat Transfer Equipment Standards

Questions and Answers

What is the minimum size for telltale vent holes in reinforcing pads?

⅛-inch

¼-inch (correct)

½-inch

⅜-inch

Where should telltale holes be located in reinforcing pads for accessibility?

At the lowest accessible position (correct)

In the center of the pad

At the highest position of the pad

At the edge of the pad

What should be used to plug telltale holes in external welded attachments?

Concrete

Grease or other non-pressure retaining materials (correct)

Silicone sealant

A metal cap

What is required for the two segments of a split reinforcing pad?

They must be welded together without a backing strip Signup and view all the answers

What size drain hole is specified for pass partition plates?

6 mm Signup and view all the answers

What is the requirement for how nozzles should be finishing on the inside of the exchanger?

Nozzles should be ground flush with a smooth corner radius 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?

25 mm Signup and view all the answers

What is the next planned update date for the Shell and Tube Heat Exchanger standards?

26 June 2020 Signup and view all the answers

What should be done if production test coupons require multiple thermal heat treatment cycles?

Apply each cycle separately. Signup and view all the answers

Which tubes require stress relief heat treatment after cold forming and bending?

Brass and Monel tubes in all services. Signup and view all the answers

Which type of tubes is required to undergo solution annealing?

Tubes made of un-stabilized stainless steels or Nickel base alloys. Signup and view all the answers

When is postweld heat treatment (PWHT) required?

When specified on the data sheet or by applicable code. Signup and view all the answers

What is stated about code exemptions for postweld heat treatment of ferritic materials?

Exemptions are not permitted for exchangers in sulfide stress cracking environments. Signup and view all the answers

Which of the following statements regarding U bends is accurate?

All U bends require stress relief heat treatment after forming and bending. Signup and view all the answers

Which materials are exempt from the requirement of postweld heat treatment, based on their electrode type?

Nickel-based electrodes used on ferritic materials. Signup and view all the answers

What is the minimum length of straight portion that must be considered for heat treatment of U bends?

150 mm from tangent line. Signup and view all the answers

Which environments do not permit code exemptions for postweld heat treatment of P4 and P5 materials?

Environments containing wet H2S Signup and view all the answers

What is the maximum post weld heat treatment soaking temperature for carbon steel?

650°C Signup and view all the answers

What should be done after completing all welding and repairs, before hydrotesting?

Conduct postweld heat treatment Signup and view all the answers

What is the proper sign that must be displayed on postweld heat treated exchangers?

Caution – Exchanger Has Been Postweld Heat Treated – Do Not Weld Signup and view all the answers

For Cr-Mo materials, what is required if alternative tempering and PWHT temperatures are to be used?

They must be qualified according to API RP 934-A. Signup and view all the answers

What is the holding temperature range for post weld heat treatment for carbon steel exchangers?

620°C – 650°C 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?

Environments with ambient temperatures Signup and view all the answers

What specification must postweld heat treatment comply with?

SAES-W-010 Signup and view all the answers

What is prohibited for weld joint categories A, B, C, and D in shell and tube heat exchangers?

Dissimilar metal welds Signup and view all the answers

What percentage of qualification time is required for welding procedures that mandate impact tests?

80% Signup and view all the answers

What type of tests must production test coupons undergo after welding, according to the specification?

Production heat treatment time and mechanical tests Signup and view all the answers

What should production test coupons simulate during hot forming?

Heat treatment cycles and post-weld heat treatment cycles Signup and view all the answers

In addition to standard requirements, what extra tests are needed for exchangers in sour service?

Impact and hardness tests Signup and view all the answers

Which standards must hardness testing comply with for sour service exchangers?

NACE MR0175/ISO 15156 Signup and view all the answers

Which document outlines the rules for the exclusion of dissimilar metal welds?

API RP 934-A Signup and view all the answers

What is a consequence of improper compliance with the impact testing requirements?

Failure of weld integrity assessment Signup and view all the answers

What factors must the Exchanger Manufacturer consider for ensuring structural stability during PWHT?

Temperature gradients in equipment wall Signup and view all the answers

Which of the following tolerances must be adhered to according to the document?

The most stringent of applicable Code, TEMA, and PIP document VEFV1100 Signup and view all the answers

What is prohibited when components do not meet fabrication tolerances?

Fitness-for-service assessment methodology Signup and view all the answers

What is the required surface roughness for non-metallic gaskets?

250 to 500 AARH Signup and view all the answers

At what surface roughness should spiral wound gaskets in hydrogen service be manufactured?

125 to 150 AARH Signup and view all the answers

Which statement regarding mechanical restraints during PWHT is correct?

They should be minimized to allow movement. Signup and view all the answers

What is the applicable surface roughness for the side-walls of ring joint flanges in any service?

63 AARH Signup and view all the answers

What must be considered in determining the dead weight at intended PWHT soaking temperature?

The heat exchanger design and contents 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.