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Thursday, December 17, 2009

TANK ERECTION PROCEDURE

*note: this is the sample document for the related job only
*author:


TABLE OF CONTENTS

1. SCOPE
2. APPLICABLE CODE
3. FOUNDATION
4. CONSTRUCTION PROCEDURE
4.1. BOTTOM PLATE
4.2. SHELL PLATE
4.3. ROOF STRUCTURE
4.4. ROOF PLATE
4.5. OUTER RAFTER ERECTION PROCEDURE
4.6. WIND PROTECTION OF SHELL PLATE AND ROOF STRUCTURE
4.7. TEST
4.8. CALIBRATION
4.9. ATTACHMENT


1. SCOPE
This specification covers construction (erection) procedure for field erection of Two (2) nos additional crude Storage Tanks.

2. APPLICABLE CODE

a. ASME IX: : Welding & Brazing Qualification

b. B31.3 : Chemical Plant, Petroleum and Refinery piping.

c. ASME V : Non Destructive Testing

d. API650 : Welded Steel Tank for Oil Storage.

e. BS 2654 : Vertical Steel Welded Non-refrigerated Storage Tank with Butt welds for the Petroleum Industry.

f. Client Technical Standard

PTS-20.156A :Standard Tank Vol. 1 – Part 1
PTS-20.156B :Standard Tank Vol. 1 – Part 2
PTS-20.156C :Standard Tank Vol. 2 – Part 3

g. Contractor Specification
: Field Inspection Procedure Specification
: Water Filling Test
: Quality Plan

3. FOUNDATION
The following item of the foundation shall be confirmed and accepted by warga Hikmat QC and Client rep (PPMSB) prior to erection of the tanks.
(Refer to PTS-20.156A – 09.00.00- Foundation)

i. Level and Direction of the foundation
ii. Camber and flatness of foundation surface

4. CONSTRUCTION PROCEDURE

(Refer to PTS-20.156B – 10.00.00 Erection & 10.02.00 Erection Procedure)

4.1 BOTTOM PLATE

(1) Arrangement and welding of the Bottom plate shall conducted as per Bottom Plate Welding Sequence in Attachment 1 and detail procedure as follow;
i. Marking of centre line.
ii. Bottom plate arrangement as per welding sequence and applicable drawing.
iii. Fitting between shell and bottom plate.

(2) Bottom plate shall be welded by back step or skip welding method.

(3) To prevent welding distortion, restraint jigs or reinforcing beams shall be used.

4.2 SHELL PLATE

(1) Prior to erection of shell plate, following marking shall be performed on the bottom plate as shown in Fig. 1 & Fig. 2

i. Marking of radius for shell erection. (The marking shall be larger than the diameter shown in the drawing, considering weld shrinkage of shell plate).
ii. Radius for checking the roundness of shell plate shall be marked.
iii. The marking allotment of 1st course of shell plate shall be carried out.
(2) Level, roundness and verticality shall be inspected after completion of erection of 1st course of shell plate.

(3) Shell plate from second to fifth course and top angle shall be erected.


(4) Welding of shell plate shall be performed from lower course, and vertical joint shall be welded prior to the horizontal joint.

4.2.1 DETAIL ERECTION PROCEDURE OF SHELL PLATE.
The sequence of erection and welding are as follow:

1) Erection of 1st course.

2) Check level, verticality and roundness of 1st course.


3) I) Erection of 2nd course. After completion of erection of second course, the vertical joint of 1st course shall be welded.
ii) Vertical joint of 2nd course shall be aligned.
iii) Local departure, tolerance cut horizontal and vertical shell seams shall be checked.

4) i) Erection of 3rd course. After completion of erection of third course, the vertical joint of 2nd course shall be welded follow by horizontal joint between 1st course and 2nd course.
ii) Local departure, tolerance cut horizontal and vertical shell seams shall be checked.

5) i) Erection of 4th course. After completion of erection of fourth course, the vertical joint of 3rd course shall be welded follow by horizontal joint between 2nd course and 3rd course.
ii) Joint between shell plate and bottom plate shall be welded.
iii) Local departure, tolerance cut horizontal and vertical shell seams shall be checked.

6) i) Erection of 5th course. After completion of erection of fifth course, the vertical joint of 4th and 5th course shall be welded follow by horizontal joint between 3rd and 4th course, and between 4th course to fifth course.
ii) Local departure, tolerance cut horizontal and vertical shell seams shall be checked.

7) i) Installation of top angle. Dimensional shall be checked prior welding the top angle to the top (last) course.
ii) Local departure, tolerance cut horizontal and vertical shell seams shall be checked.

4.3 ROOF STRUCTURE

i. Roof structure shall be assemble on the ground in section or completed depending on size and weight.

ii. Assembled roof structure shall be erected inside the tank after completion of bottom plate and annular plate.

4.4 ROOF PLATE
Roof plate shall be arranged on the roof structure and welding to be carried out according to welding sequence considering the distortion or warping of plates.

4.5 OUTER RAFTER ERECTION PROCEDURE
Roof of outer rafter shall be assemble on the ground in section or completed depending on size and weight. The sequence of assembly are as follow;

1. Assemble the roof plate on the temporary support.

2. Assemble and welding the center ring and center plate complete with stiffener and rib plate.

3. Fit the ring on the roof plate.

4. Install the rafter and girder on the roof plate.

5. Erect the outer rafter on the temporary support after completion of bottom plate and annular plate.

4.6 WIND PROTECTION OF SHELL PLATE AND ROOF STRUCTURE
Shell plate and roof structures shall be protected by heavy wind during the erection using guy wire rope method. A detailed execution procedure and/ or plan including the detailed dimensions of the device shall be prepared and submitted to CLIENT site for approval, prior to commencement of shell construction work.

4.7 TEST
After completion of the entire tank, test shall be performed in accordance with WH FIELD INSPECTION & TEST PROCEDURE SPECIFICATION.

4.8 CALIBRATION
After completion of the required test, the tank shall be calibrated in accordance to WH FIELD INSPECTION & TEST PROCEDURE SPECIFICATION.

4.9 ATTACHMENT:

1. Fig 1 AND Fig 2.
2. Welding Sequence For Bottom Plate.



11 comments:

  1. This comment has been removed by the author.

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  2. This comment has been removed by the author.

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  3. Nice information .You have given some detailed information on steel tank erection. I came across another site that gave similar info but it was more graphical and generic while yours is more detailed and hands on. Thanks for the info.

    ReplyDelete
  4. I haven’t known about it before. This article is very helpful!
    Thank you so much!
    Tank Calibration Services

    ReplyDelete
  5. do you mean weld all vertical joint of course or let last vertical joint of course welded later

    ReplyDelete
  6. hii.. can you explain me in details about tolerances as per api 650. suppose tolerance was given +-19mm for radius then how we check it in construction.

    ReplyDelete
  7. Asslam O Alikum,

    We repair 30 dia meter tank bottom plates. please assure to me what is the root gap between annular plates. as you all know if we repair old tank annular plate it's so critical. some time our annular plate root gap is 4.5 mm to 5.5 mm and some time its 4 mm to 6 mm. please share the reference about this.

    early response shall be highly appreciated.

    ReplyDelete
    Replies
    1. In EN standard I think , maximum allowed gap is 3 mm ; also , my expirience : shell to annualar plates welding after cca 70% of tank shell weight , and annular plates to bottom plates - last welding operation .

      Delete
  8. Thanks for this Post… Calibration is the process of accurately determining the capacity or partial capacities of a tank and expressing this capacity as a volume for a given linear increment or height of liquid. In other words, Tank Calibration Services also means measuring storage tanks, horizontal bullets, spherical tanks, vats, casks, barges, ship tanks and liquid bulk containers. These measurements provide the necessary dimensions for calculation of calibration charts.
    Eddy Current Testing
    Water bag rental in Saudi
    Storage TanK Survey

    ReplyDelete
  9. ello dear,
    I'm a construction engineer for tanks and pressure vessels with two years experience in this field, i saw your article engineering procedure on the blogspot
    I just want more information about that project you execute to help me with mine.
    Thank you very much.

    ReplyDelete