Inspection of Heat Exchangers Saad G.AL-Dufairi BGP-Inspection Unit July4,2005
Outline • • • • • • • •
Objective. Types of Heat Exchangers. Saudi Aramco Specifications, F175 Forms. Industrial Standards & Codes.
TEMA Classifications. Air-Cooled Heat Exchangers. Primary Process Functions of Heat Exchangers.
Fabrication steps through ITP.
Objective
• Identify the main types of heat exchangers and their primary components..
• • • •
Inspection, and testing procedures for heat exchangers. Saudi Aramco Specifications and F175 Forms. Industry Standards And Codes.
Evaluate vendor fabrication drawings for suitability, using 32-SAMSS-007, 32-SAMSS-011, TEMA, and API standards.
• Describe the use of 32-SAMSS-007, 32-SAMSS-011, and industry codes and standards to determine heat exchanger inspection and testing requirements.
Types of Heat Exchanger The main types of heat exchangers that are used by Saudi Aramco are as follows:
• • • •
Shell-and-tube heat exchangers Air-cooled heat exchangers Double-pipe heat exchangers Plate-and-frame heat exchangers
Types of Heat Exchanger Shellside Flow In Tubeside Flow Out Shell
Tube Bundle
Shellside Flow Out Tubeside Flow In
Shell-and-Tube Heat Exchanger
Types of Heat Exchanger
Air Seal
Tube Keeper (top)
Lifting Lug
Air Seal Header
Tube Nozzle
Header
Fins Tube spacer
Side Frame
Typical Air-Cooled Heat Exchanger
Tube Support (bottom)
Air Seal
Types of Heat Exchanger Shell Cover Gasket Vent
External Fin Pipe Shell
Shell Cover
Return Bend (welded) Drain
Sliding Support Twin Flange
Double-Pipe Heat Exchanger
Fixed Support Shell End Piece
Types of Heat Exchanger
Aout
Bin
Nozzle Header
Separating Sheet
Cin
Corrugated Sheet
Effective Width
Heat Transfer Section Effective
A
Length
Side Bar Distributor
Distribution Section
Cout
Bout
Ain
Plate-and-Frame Heat Exchanger2
B
SA Specifications • 32-SAMSS-007 • 32-SAMSS-011 • 32-SAMSS-028 Exchangers • SAES-E-004
• SAES-E-006 • SAES-E-007 • SAES-E-014 • SAES-E-015
Manufacture Of Shell And Tube Heat Exchangers Manufacture Of Air-Cooled Heat Exchangers Inspection Manufacture of Double Pipe Heat Design Criteria Of Shell And Tube Heat Exchangers Design Criteria of Double Pipe Heat Exchangers Design Criteria Of Air-Cooled Heat Exchangers Design Criteria Of Plate And Frame Heat Exchangers Design Criteria Of Electric Heat Exchangers
Saudi Aramco Inspection Requirements Forms SA F 175
• Form 175-323100
Manufacture of Shell And Tube Heat Exchangers
• Form 175-323500
Floating Heads or Tube Bundles
• Form 175-323600
Manufacture of Air-Cooled Heat Exchangers
• Form 175-323300
Manufacture of Plate & Frame
Industrial Standards
• ASME SEC VIII D1/D2
Rules for Construction of Pressure Vessels
• TEMA
Standards of the Tubular Exchanger Manufacturer's Association
• API 660
Shell and Tube Heat Exchangers for General Refinery Services
• API 661
Air-Cooled Heat Exchangers for General Refinery Service
TEMA Classifications TEMA Class
Application
Example
__________________________________________________________________________________________________________________________________________
R
Severe environments
Refineries
C
Moderate service
Building services, commercial, and general process industries
B
Chemical process
Chemical manufacturing
TEMA Classifications Design Item
Class/Service R/Refinery
C/General
B/Chemical
1/8 in.
1/16 in.
1/16 in.
Minimum Thickness of Shell
See Table R3.13
See Table CB-3.13
See Table CB-3.13
Minimum Tie-Rod Diameter
3/8 in.
¼ in.
¼ in.
1/32 in., max.
None
None
¾ in.
½ in.
5/8 in.
Corrosion Allowance (carbon steel)
Gasket Contact-Surface Tolerance
Minimum Bolt Size
TEMA Size and Type Normally Written: 23–192 AES
23” Shell I.D.
Type “A” Channel
Straight Tube Length 192” (16’ – 0”)
Type “E” Shell Single-Pass
TEMA Designation System Example
Type “S” Split-Ring Floating Head
TEMA Types
Acceptable Exchanger Components Materials for Carbon and Alloy Steels Design Temperature Exchanger Component
(Note: The numbers in ( ) refer to the specific notes at the end of the table)
-100ºC - 47ºC (-150ºF - 51ºF)
-46ºC - 0ºC (-50ºF - 32ºF)
1ºC - 425ºC (33ºF - 800ºF)
351ºC - 645ºC (651ºF 1200ºF)
SA-516 Grade 70N, or SA-537 Class 1
SA-516 Grade 70 or SA-537 Class 1 or SA-285 Grade C (1)
SA-387 Grade 11
Shells, Channels, Dished Heads, Tube sheets, Rolled Nozzle Necks, Covers, and Reinforcing Pads
SA-203 Grades D or E
Pips, Nozzle Necks
SA-333 Grade 3 SA-333 Grade 6 SA-106 Grade B SA-53 Grade B (1)
Shell and Tube Heat Exchangers
SA-335 P11, 12 or 22
Air-Cooled Heat Exchangers • Forced-draft Air forced across tube bundle by fan located in air plenum
below bundle.
• Induced-Draft Fan located above hood covering tube bundle. Air pulled across tube bundle and exhausted through hood.
• Humidified Forced-Draft Air humidified before forced across tubes. Evaporation draws heat from air and cools air below
temperature of process fluid.
Air-Cooled Heat Exchangers Tube Bundle
Inlet Nozzles
Return Header(s) Inlet Headers Outlet Headers Outlet Nozzles
Supports
Plenum
Fan
Fan Ring Drive Assembly
Typical Forced-Draft Air-Cooled Heat Exchanger
Air-Cooled Heat Exchangers Hood or Plenum
Fan Ring Fan Return Headers
Inlet Nozzles
Inlet Headers
Outlet Headers
Outlet Nozzles
Tube Bundle Drive Assembly
Supports Horizontal Tube, Induced-Draft Air-Cooled Heat Exchanger
Air-Cooled Heat Exchangers Hot Air Tube Bundle
Process Nozzle Partition Plate
Header
Plenum Chamber
Header Fine Water Mist
Forced Draft Fan
Process Nozzle Water Header Nozzles (above fan Typical)
Water Header Nozzles (below fan Sometimes)
Humidified Forced-Draft Heat Exchanger
Acceptable Materials for Fin fan cooler Design Metal Temperature Exchanger |Component
(Note: The numbers in ( ) refer to the specific notes at the end of the table)
-46ºC to 0ºC (-50ºF to 32ºF)
1ºC to 425ºC (33ºF to 800ºF)
351ºC to 645ºC (651ºF to 1200ºF)
Header Plates, Pass Partition Plates and Stiffener Plates
SA-516 Grade 70N or SA-573 Class 1
SA-516 Grade 70, or SA-537 Class 1 or SA-205 Grade C (1)
SA-387 Grades 11, 12 or 22
Nozzle Necks
SA-333 Grade 6
SA-106 Grade B SA-53 Grade B (1)
SA-335 P11, 12 or 22
Tubes (inner) (2)
SA-334 or SA-249 Type 304
SA-179 or SA-214
SA-179 or SA-214 or SA-213 Type 304
Forged Flanges, Forged Fittings, and Plugs
SA-350 LF2
SA-105N
SA-182 F11, 12, or 22
Wrought Fittings
SA-420 WPL6
SA-234 WPB
SA-234 F11. 12. pr 22
Studs/Nuts for Pressure Connections
SA-320 L7 w/ SA-194 Grade 2H
SA-193 B7/ SA-194 Grade 2H
SA-193 B5, or B16/SA-194 2H, or 3
Primary Process Functions of Heat Exchangers
• Change temperature of a fluid • Change phase of a fluid.
Fabrication steps through ITP
• Fabrication drawing should be issued for constriction. • Welding Procedure Specification (WPS) & Procedure Qualification Record (PQR) shell be approved by CSD.
• Material certificates to be 3.1B for pressure parts plus NACE TM0284 for HIC service.
• Certificate should include material chemical analysis & mechanical test.
• Verification of heat number between certificate and actual material.
• Material traceability. (hard punching prior to cutting)
Fabrication steps through ITP (2)
• • • • • • • • •
Layout marking for cutting of shell and header box. Rolling & edge preparation of long seam & circ seams. Re-rolling after long seam. Fit-up of long seams then circ seams. Layout marking of all nozzles pipe. Fit-up of flange to neck pipe. Marking of all nozzles on shell & channels.
Bevel edge preparation of nozzle opening. Fit-up of nozzles to shell & Channels.
Fabrication steps through ITP (3)
• Layout & drilling of baffle plate & tube sheet . • Tube bundle preparation & assembling of tubes, tierods, spacers etc, to tube sheet.
• • • • • •
Tube expansion to be between 5.0% to 10%. Post Weld Heat Treatments (PWHT) if required. NDE (RT, UT, MT & PT) and Hardness test. Final visual & dimensional test. Pneumatic test of all reinforcements pads at 30 KPA. Hydrotest of shell side, tube side then channels side.
Fabrication steps through ITP (4)
• • • •
Draining the whole equipment. Verification of “U” stamp and name plate. Surface preparations, blasting then coating. Fin-fan coolers shall be completely drained with dry air to an exit dew point of less than -1°C.
• Internal surface protection by corrosion inhibitor such as CORTEC VCI-309, VCI-307 or 5 PSIG of nitrogen blanket.
• Shipment release.
Thank you
