Date post: | 04-Jun-2018 |
Category: |
Documents |
Upload: | jignesh-pandya |
View: | 289 times |
Download: | 3 times |
of 37
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
1/37
INSPECTION OF DOUBLETUBESHEET HEAT EXCHANGERS
AT CONFERENCE HALL ON 2 ND DEC.2005
Presented by Mr. Prasad Pathak
For the benefit of business and people
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
2/37
2
1 Information Double T/S H.E.
2 Thumb rules
3 Introduction
4 Tube Sheet Details
5 Tube To Tube Sheet Joint
6 Tube Sheet To Tube Sheet Joint
7 Requirement Of Mock Up8 Mock Up Testing
6.1 DIM. Report of Mock Up
6.2 Expn. Record of Mock Up
6.3 Pull Out Record of Mock Up
9 Problems Incurred
10 Customers Concurrence
11 Conclusion
CONTENTS
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
3/37
3
INFORMATION ON DOUBLE TUBE
SHEET HEAT EXCHANGERS
1
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
4/37
4BUSINESS TRANSITION THE ROAD AHEAD
INTEGRAL DOUBLE TUBESHEETS
HEAT EXCHANGERS
The tube sheet are connected in a manner which:-Distributes axial load.
Distributes radial thermal expansion loads .
The interconnecting element is capable of preventing individual radial growthof tubesheet.
ASSUMPTIONS:
Element is rigid enough to mutually transfer all thermal and mech. radialloads between t/sheets.
Tubes are rigid enough to mutually transfer all mechanical and thermal axialloads between the tubesheets
DOUBLE TUBESHEET EXCHANGERS1
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
5/37
5BUSINESS TRANSITION THE ROAD AHEAD
CONNECTED DOUBLE TUBESHEETS
HEAT EXCHANGERS
The tube sheet are connected in a manner which :-
Distributes axial load between tubesheets by means of cylinder.
The effect of differential radial growth between t/s is a major factor intube stresses and spacing between t/sheets
ASSUMPTION:
Interconnecting cylinder and tubes are rigid enough to mutuallytransfer all mech. and thermal axial loads between the tubesheets.
1 DOUBLE TUBESHEET EXCHANGERS
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
6/37
6BUSINESS TRANSITION THE ROAD AHEAD
SEPARATE DOUBLE TUBESHEET
HEAT EXCHANGERS
The tube sheets are connected only by inter connecting tubes.
The effect of differential radial growth between t/s is a major factor in tube
stresses and spacing between t/sheets
ASSUMPTIONS:-
No loads are transferred between the tubesheets.
1 DOUBLE TUBESHEET EXCHANGERS
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
7/377
THUMB RULES IN STREAMALLOCATIONS
2
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
8/378BUSINESS TRANSITION THE ROAD AHEAD
PRACTICAL GUIDELINES FOR OPTIMUM DESIGN
FLUID STREAM ALLOCATIONS:-
The higher pressure fluid normally flows through the tube side. With smallerdiameter and nominal wall thk. the tubes are better able to accept highpressures.
Thus larger diameter is avoided for larger pressures.
Generally corrosive fluids are in the tubeside. This is much less expensive touse the special alloys designed to resist corrosion for tubes than for shell.
Flow of higher fouling fluids through the tubes are easier to clean usingcommon mech. methods than the shell .
THUMB RULES IN STREAM ALLOCATIONHEAT EXCHANGERS2
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
9/379BUSINESS TRANSITION THE ROAD AHEAD
It is best to place fluids requiring low pressure drops in the shell circuitsince flexible combinations & configurations- affecting tube pitch, baffle useand spacing, and multiple nozzles etc can be used when laying out the shellcircuit.
The fluid with lower heat transfer coeff. normally goes in the shell circuitwith this setup, low-fin tubing, which will increase available surface area,canbe used to offset the low heat transfer.
THUMB RULES IN STREAM ALLOCATIONCONTD HEAT EXCHANGERS2
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
10/3710
INTRODUCTION
3
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
11/3711BUSINESS TRANSITION THE ROAD AHEAD
HEAT EXCHANGERS3
Usually we come across inspection of straight tube and U tube HeatExchangers with single Tube sheet at either ends or single Tube sheet at oneend(U tube HE).
TEMA provides option for using Double Tube sheet HE to get a bettercontamination-proof joint.( ref.TEMA RCB pg.55-62)
Such design of exchangers are popular in Pharma industries whereintermixing of shell side and tube side fluid are totally to be avoided forprocess reasons.
It would be worthwhile attempting to describe how the double tube sheetavoids intermixing. Pl. refer the figure.
INTRODUCTION
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
12/3712BUSINESS TRANSITION THE ROAD AHEAD
HEAT EXCHANGERS3 INTRODUCTION
HEAT EXHCHANGER DETAILS
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
13/3713BUSINESS TRANSITION THE ROAD AHEAD
HEAT EXCHANGERS
TYPICAL JOINT DOUBLE TUBESHEET
INTRODUCTION3
Inner T/SOuter T/S
ChannelShell
Tubes
Shell
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
14/3714BUSINESS TRANSITION THE ROAD AHEAD
GENERAL DETAILS ABOUT THE JOB INCLUDING OVERALL DIMNS. :
HCL Hydrogenation Heater for Reliance Industries Limited ,HaziraPROCESS FLUID:- SHELL SIDE - HCL / TUBE SIDE - STEAM*U Tube Double Tube sheet HE.
DIMENSIONS :
Overall Length 6931 mm.
SHELL ID 440 mm x 12 Thk, TUBESHEET 476 ODMATERIAL :
Shell / Dish end SA 516 Gr 70
Tube sheet SA 350 Gr LF2 46mm & 71mm ThK
U Tubes SA 334 Gr 6 19.05 OD x 2.77 mm thk
HEAT EXCHANGERS
* SINCE THE PROCESS FLUID WAS STEAM, CUSTOMERCONFIRMATION OF IBR WAS SOUGHT.
INTRODUCTION3
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
15/37
15
TUBE SHEET DETAILS
4
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
16/37
16BUSINESS TRANSITION THE ROAD AHEAD
TUBE SHEET DETAILS
TubeSheet - SA 350 Gr LF2. X 476 dia.
First T/s 46mm( inner) & second 71 mm ( outer).
Each T/s having two grooves of 3mm width and 0.4mm depth.
148 No of holes each of Dia. 19.25mm on 25.4mm traingular pitch.
4 HEAT EXCHANGERS
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
17/37
17
TUBE TO TUBE SHEET JOINT
5
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
18/37
18BUSINESS TRANSITION THE ROAD AHEAD
TUBE TO TUBE SHEET JOINT5
Tube SA 334 Gr 6 Size 19.05mmx 2.77 mm ThkFully expanded joint.
8 to 10% expansion% Thinning check and air test after expansion.
HEAT EXCHANGERS
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
19/37
19
TUBE SHEET TO TUBE SHEETJOINT
6
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
20/37
20BUSINESS TRANSITION THE ROAD AHEAD
TUBE SHEET TO TUBE SHEET JOINT6
Full penetration joint with 25 mm gap in between the Tube sheets.
NDT as per drawing MPINDT suggested PT and UT in addition to MPI.
HEAT EXCHANGERS
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
21/37
21
REQUIREMENT OF MOCK UP
7
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
22/37
22BUSINESS TRANSITION THE ROAD AHEAD
WHY THE MOCK UP WAS REQUIRED TO BE DONE:
( TEMA DOESNT CALL FOR SUCH TESTS FOR U -TUBE EXCHANGERS)
To establish expansion parameters.
To check % thinning after expansion
To check axial load (pull out ) of tubes after expansion.
To check proper flow of tube material in the T/s grooves afterexpansion.
To freeze the sequence of the expansion of the T/s to Tube joint.
REQUIREMENT OF MOCK UP7 HEAT EXCHANGERS
SINCE TUBE SHEET ASSLY HAD DOUBLE EXPN. PORTION,IT WAS ESSENTIAL TO DEMONSTRATE THE EXPANSION
ACHIEVED IN THE INNER TUBESHEET.
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
23/37
23
MOCK UP TESTING
8
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
24/37
24BUSINESS TRANSITION THE ROAD AHEAD
MOCK UP TESTING
DESCRIPTION OF THE MOCKUP:-
Tube sheets with same configuration as required in job.
17 No of holes used.
Pull out test carried out on Hole nos. 4,9&14 ,surrounded by at least tworows.
Expansion in two stages.
% expansion checked in both Tube sheets with bore gauge.
ADDITIONAL TESTS DONE ON THE MOCKUP:
After satisfactory expansion, the joint with annular space was seal weldedfirst and then subjected to pneumatic test at 2.0 kg/cm2(g). pressurefollowed by hydro test at 33.0 kg/cm2(g) and the results were leak tight.
8 HEAT EXCHANGERS
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
25/37
25BUSINESS TRANSITION THE ROAD AHEAD
DIM. REPORT OF MOCK UP8.1 HEAT EXCHANGERS
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
26/37
26BUSINESS TRANSITION THE ROAD AHEAD
EXPN. RECORD OF MOCK UPHEAT EXCHANGERS8.2
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
27/37
27BUSINESS TRANSITION THE ROAD AHEAD
PULL OUT RECORD OF MOCK UPHEAT EXCHANGERS8.3
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
28/37
28BUSINESS TRANSITION THE ROAD AHEAD
The pull out loads were found to be satisfactory when the tests were done :-
1. Required load - 56 kn actual 80 kn
2. Macro test was conducted after sectioning to confirm the proper flowof tube material in the grooves after expansion, the flow of material was
satisfactory.
3. Hardness test were done on the inner expanded & unexpandedsurface of the tube and was with in 187 bhn.
8.4 HEAT EXCHANGERSPULL OUT RECORD OF MOCK UP
CONTD..
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
29/37
29
PROBLEMS INCURRED
9
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
30/37
30BUSINESS TRANSITION THE ROAD AHEAD
PROBLEMS INCURRED9.1
REQUIREMENT OF EXTRA LONG DIAL BORE GAGE FOR THE INNERTUBESHEET:
In mock up stage , both ends of the tube sheets were accessible and henceit was easy to check % expansion in both the tube sheets separately.
In actual job, only one end was accessible. So it required a long bore gaugeto check the expansion. Since the fabricator was not having the long boregauge,expansion of the outer T/s was checked and reported. The same wasreferred to client for concurrence and was accepted by them based onsatisfactory mock up results.
HEAT EXCHANGERS
PROBLEMS INCURRED
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
31/37
31BUSINESS TRANSITION THE ROAD AHEAD
NDT SPECIFIED FOR THE EQPT WAS 100% RADIOGRAPHY :-
BV insisted the above requirement for the T/S TO T/Sheet weld joint
Due to the joint geometry, radiography could not be realised. UT was thenext suggested alternative. Again due to joint configuration /lesser widthof joint & limitation of scanning area only a small portion could be
examined leaving out the critical root penetration.
To counter this, special care for the root pass was undertaken by keeping3 visible ports for examining the root penetration visually. The rootpenetration was found satisfactory.
As per approved QAP only MP examination was specified for this jointand hence accepted on this basis.
HEAT EXCHANGERSPROBLEMS INCURRED
CONTD..9.1
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
32/37
32BUSINESS TRANSITION THE ROAD AHEAD
BV INSPECTION REPORT9.2 HEAT EXCHANGERS
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
33/37
33BUSINESS TRANSITION THE ROAD AHEAD
BV INSPECTION REPORTCONTD..HEAT EXCHANGERS9.2
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
34/37
34
CUSTOMERS CONCURRENCE
10
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
35/37
35BUSINESS TRANSITION THE ROAD AHEAD
CUSTOMERS CONCURRENCE 10 HEAT EXCHANGERS
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
36/37
36
CONCLUSION
11
8/14/2019 Inspection of Double Tube sheet exch.Presentation1.ppt
37/37
CONCLUSION
TEMA does not give too much details about such type of Double T/s HE.
Maximum care was taken to do all possible testing and checks toestablish fool proof joint.
Still a better version of checks and testing may be possible.
Any additional information and experience on this topic is welcome.
HEAT EXCHANGERS11