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Thursday, December 17, 2009

FIELD INSPECTION AND TEST PROCEDURE

*note: this is the sample document for the related job only
*author: theprocedure@engineer.com

TABLE OF CONTENTS

1. Scope
2. Applicable Code, Standard And Specification
3. General
4. Material Inspection
    4.1 Material Receiving Inspection
5. Material Traceability Control
    5.1 Extent of Traceability Control
6. Dimensional Inspection
    6.1 Foundation Receiving Inspection
    6.2 Location Mark Check
    6.3 Fit-up Inspection
    6.4 Roundness
    6.5 Plumbness
    6.6 Local Deviation
7. Nondestructive Examination
    7.1 Visual Inspection
    7.2 NDE Procedure
    7.3 Radiographic Examination (RT)
    7.4 Liquid Penetrant Examination (PT)
    7.5 Vacuum Box Test (VBT)
    7.6 Pneumatic Leak Test (LT)
    7.7 Repair and Re-examination
8. Hydrostatic Test
    8.1 Pre-test Check
    8.2 Water Filling
    8.3 Settlement Monitoring
    8.4 Hydrostatic Test
    8.5 Cleaning
    8.6 Hydrostatic Test for Heating Coil
9. Fixed Roof Test
10. Paint Inspection
11. Tank Calibration
12. Final Inspection
13. Witness Inspection
14. Manufacturer’s Data Report

1. Scope
This document covers the inspection and test requirements of storage tanks at the construction site specified for the Two (2) nos additional PSR-2 Crude storage tank at Petronas Penapisan Melaka. (PPM)

2. Applicable Code, Standard And Specification
The following standards, code, and specifications have been used as a source of information in the preparation of this document.
API Standard
API 650-9th Ed. 1995 : Welded Steel Tanks for Oil Storage
ASME CODE
ASME SEC. VIII DIV.1 : Rules for Construction of Pressure Vessels
ASME SEC.V : Nondestructive Examination
ASME SEC.IX : Welding and Brazing Qualifications
WH’S SPECIFICATION
: Construction (Erection) Procedure Specicification
: NDT (Non Destructive Procedure)
: Scheme for Water Filling Test and Settlement Measurement
: Quality Plan

3. General
(1) Unless otherwise specified in this specification, inspection and testing shall be performed in accordance with WH’s Quality Plan and applicable codes, standards and PTS.

(2) Field QC personnel shall carefully follow the construction and testing of tanks, and shall make sure that it complies in all details with design, construction, inspection and tests specified by the applicable codes, standards and specification.

4. Material Inspection
4.1 Material Receiving Inspection
Visual inspection of incoming material including the fabricated tank material sent from the shop, shall be made by the field QC personnel to ensure that there is no injurious defect on the surface and cut edges. Check on the identification number of raw material shall be made against material certificates. Check on the erection mark of fabricated tank material shall be made against the corresponding drawings.

5. Material Traceability Control
5.1 Extent of Traceability Control
The following tank components are required to be traceable against the material certificate. The As-built Sketch shall be prepared upon completion of the erection.
a. Shell Plate
Coded marking made at shop can be used to identify the material and be recorded in As-built Sketch. As-build Sketch may be supported by the related material identification records sent from shop.

6. Dimensional Inspection

6.1 Foundation Receiving Inspection
All the stage of receiving tank foundation, the field QC personnel shall review the foundation inspection report. Spot check of actual dimension and bench mark shall be made against the report.

6.2 Location Mark Check
Prior to the primary laying-down or erection of Bottom Plate, Bottom Sketch Plate, Shell Plate, Roof Structures and Roof Plate, the field QC personnel shall check the location marking in accordance with the related orientation drawings. Similarly, prior to make the Nozzle/Manhole opening, the location marking of opening shall be ensured.


6.3 Fit-up Inspection
Weld preparation and dimensional accuracy shall be checked prior to start welding. Butt welds of Shell joints shall be matched accurately and retained in position during welding operation.
Misalignment of Shell weld joint shall not exceed the following tolerance.
a. In completed shell vertical joint
Shell Plate  15.8 mm thk : 1.6 mm
b. In completed shell horizonttal joint
Upper Plate  15.8 mm thk : 1.6 mm
For Bottom Annular butt weld, the tolerances of vertical joints shall be applied.

6.4 Roundness
Prior to commencement of shell to Bottom Sketch plate weld, the tank internal radius shall be measured. The horizontally measured tank radius at 300 mm above the bottom corner weld shall not exceed the following tolerances.
Tank < 12 m diameter : + 13 mm 6.5 Plumbness The first course shell plate shall be checked for plumbness, level and roundness before welding in accordance with WH’s construction procedure to ensure that the tank will be completed within the specified dimensional tolerances. Plumbness of Shell shall be inspected after completion of all Shell welds. The out-of plumbness shall not exceed 1/200 of the total tank height. 6.6 Local Deviation Local deviation shall be inspected, if there is any noticeable distortion after completion of shell weld. The Local deviation shall not exceed the tolerance of 13 mm. 6.7 All nozzle and couplings directly connected with piping shall be at the correct elevations from the surface of bottom plate and radial positions after completion of welding and erection and remain at the following tolerance. Elevation of nozzle : + 10 mm Radial position of nozzle : + 15 mm Nozzle projection : + 10 mm Inclination of flange face : + 0.5°  

7. Nondestructive Examination

7.1 Visual Inspection
Regardless any other nondestructive inspection method applied, all the site welds shall be subjected to visual inspection, and meet the requirements of API 650 Sec. 6 para 6.5.

7.2 NDE Procedure
General requirements, examiner’s qualification, equipment and operation procedure of nondestructive examination shall be in accordance with WH Specification : Nondestructive Test Procedure.

7.3 Radiographic Examination (RT)
The following RT shall be performed.
a. Shell vertical / horizontal joints and bottom annular radial joints shall be radiographed in accordance with the requirement of API 650 Sec. 6 para 6.1.
Heating coil butt joints shall be radiographed on spot basis. Minimum 5% butt joints of heating coil welded by each welder shall be fully radiographed.
b. Radiographs shall be judged in accordance with API 650 Sec. 6 para 6.1.5.
c. When a spot radiograph fail to comply with the acceptance standard, additional radiographs shall be taken in accordance with the requirement of API 650 Sec. 6 para 6.1.6.

7.4 Liquid Penetrant Examination (PT)

The following PT shall be performed.
a. The attachment welds of nozzle / manhole welded to shell at site shall be examined by PT.
b. The acceptance standard shall be in accordance with API 650 sec. 6 para 6.4.4.

7.5 Vacuum Box Test (VBT)

The following vacuum box test shall be performed.
a. All Bottom welds, i.e. Bottom-to-Bottom, Sketch Bottom Sketch-to-Bottom Sketch, Bottom Sketch-to-Shell joints, shall be inspected.
b. Any leakage observed by VBT is unacceptable.

7.6 Pneumatic Leak Test (LT)

The following pneumatic leak test shall be performed.
All attachment weld of reinforcement plate on each shell opening welded at site shall be inspected in accordance with API 650 Sec. 5 para 5.3.5. Any leakage observed by LT is unacceptable.

7.7 Repair and Re-examination

When an imperfection is judged to be repaired by welding, repair welding shall be make in accordance with the applicable welding procedure. Repaired are shall be re-examined by the same method originally used.

8. Hydrostatic Test


8.1 Pre-test Check
a. Before filling water into the tank, it shall be ensured that all inspection on Bottom, Shell and Roof including attachment welds shall be completed.
b. Any foreign articles shall not be left in the tank.

8.2 Water Filling
a. The water filling rate shall be decided with consideration given to tank size, pump facilities, water supply available, stability of foundation settlement, and other matter relating to safety.
b. When foundation settlements are negligible or significantly greater than expected settlement, water filling rate may be changed.
c. During the entire filling and emptying operation, roof manhole and/or other openings shall be kept open.
d. During the water filling, the floating roof shall be checked frequently for leaks.

8.3 Settlement Monitoring
a. Settlement reading shall be take at a minimum of 4 points around the base of tank.
b. Settlement reading shall be taken and reported to Contractor at least once a day while the tank is being filled with water and emptied.

8.4 Hydrostatic Test
a. Water shall be filled to the specified test level as WH Spec.
b. After the tank filled to test water level, all welds in the shell, including shell to bottom Sketch Plate welds, shall be visually inspected for water tightness.
c. Water shall be maintained at the test level for minimum of 24 hours after which water may be discharged.
d. Prior to starting the water discharging, ensure that the roof openings are opened.

8.5 Cleaning
a. During and after the tank is emptied, the inside of tank shall be cleaned.
b. All sand, sludge and rubbish on the tank bottom shall be removed.

8.6 Hydrostatic Test for Heating Coil
Heating coil shall be tested hydrostatically at a pressure specified in applicable drawing.

9. Fixed Roof Test
While the tank is maintained at the test water level, welds on the fixed roof shall be pneumatically leak tested. Non-pressure tank roofs shall be tested to pressure not exceeding the weight of the roof plates with compressed air and low-pressure tank roofs shall be tested to a pressure equal to the maximum internal pressure rating. The inaccessible are during hydrostatic test shall be inspected in advance by vacuum box.

10. Paint Inspection
Paint inspection shall cover the following items.
a. paint material check
b. surface preparation check
c. paint application check
d. dry film thickness (DFT) check
e. visual inspection of completed surface
f. pinhole test for tank internal lining

The magnetic pull-off type gauge or fixed probe magnetic flux type gauge shall be used for DFT readings. For each coat of paint, the DFT shall be taken at a frequency of one measurement of every 10 square meters area. Each measurement consists of an average of three gauge readings next to one another. All spot measurements shall not be less that 100% of the specified DFT.
After the final coating has been completed, the field QC personnel shall ensure that the appropriate clean-up is done, and that any abrasions, nicks or scrapes are repaired as required.

11. Tank Calibration
Tank calibration and preparation of gauge table shall be performed by a specialized firm in accordance with internationally accepted method and with local statutory requirements.

12. Final Inspection
Prior to tank box-up, the inside of tank shall be thoroughly ensured clean. Flange surfaces of Nozzle/Manhole shall be carefully inspected for defects which may caused and leakage.
It shall be also ensured that all works required by drawings, specifications and the related inspection and test plan have been thoroughly completed.

13. Witness Inspection

The scope of inspection by Vendor, CONTRACTOR, and OWNER is indicated in Scope of Inspection. The Inspection and Test Plan shall be progressively followed by the inspector throughout site construction.

14. Manufacture’s Data Report (MDR)
The site portion of MDR shall be compiled at site as the construction is progressing. The completed site MDR shall be submitted to CONTRACTOR, while a original copy will be sent to WH home office for retaining. As a minimum, the following inspection records shall be included in the site MDR as per Quality Plan.
a. Inspection Certificate
b. As-built Sketch of Shell Plate
c. Welders Map of Shell and Bottom Plate/WPS & PQR/Welder’s Qualification Records
d. NDE Record of RT, PT, VBT and LT
e. Dimensional Inspection Record of Tank Foundation, Roundness and Plumbness
f. Hydrostatic Test Record including settlement data
g. Roof Test Record
h. Paint Inspection Record

1 comment:

  1. how to calculate air pressure for fixed roof testing

    ReplyDelete