PROCEDURE FOR VACUUM BOX TEST

(WRITTEN IN ACCORDANCE TO API 650)

1.0 SCOPE

This procedure provides a system of general conditions and specific instructions as an aid to personnel required to perform leak test vacuum box technique.

2.0 GENERAL REQUIREMENTS

2.1 The bubble forming solution shall produce a film that does not break away from the area to be tested and the bubbles formed shall not break rapidly due to air drying or flow surface tension. The number of bubbles contained in the solution shall be minimized to reduce the problem of decrementing between existing bubbles and those caused by leakage.

2.2The bubble forming solution shall be compatible with the temperature of the test conditions.

3.0 EQUIPMENT AND MATERIALS

3.1Vacuum box A metal or fiberglass box of convenient size and shape (e.g. flat vacuum box, angle vacuum box etc) with a glass window in the side opposite the open bottom. The open bottom edge shall be equipped with a suitable gasket to form a seal against the test surface.3.2Vacuum gauge range 0 psi to 15 psi.

3.3Air ejector3.4Air compressor

4.0PROCEDURE

4.1Connect the air ejector to the vacuum box and install the gauge. Connect the compressed air hose to the air ejector. The gauge shall register a partial vacuum of at least 2 psi below atmospheric pressure.

4.2The area to be tested shall be free from oil, grease, paint, and other contaminated which might mask a leak. If liquids are used to clean the component, it shall be dry before performing leak testing.

4.3All openings shall be sealed using plugs, covers, sealing wax, cement, or other suitable material which can rapidly and completely removed after completion of the test.

4.4All gauges used shall be calibrated against a standard deadweight tester, a calibrated gauge master or a mercury column and recalibrated at least once a year.4.5The temperature of the test surface should not be below 40 F or above 125 F throughout the examination.

4.6Apply bubble forming solution to the surface to be tested by flowing, spraying, or brushing the solution over the examination area before placement of the vacuum box.

4.7The vacuum box shall be placed over the solution coated section of the test surface and the box excavated to the required partial column.4.8Apply a partial vacuum of at least 2 psi gauge inside the box for at least ten seconds.

4.9The presence of continuous bubble growth on the surface for the material or weld seam indicates leakage through an orifice passage in the region under examination.

5.0EVALUATION OF INDICATIONS

5.1The area under test is acceptable when no continuous bubbling is observed.

5.2When leakage is observed, the position of the leaks shall be marked. After repairs have

been made, the repaired area shall be retested using this procedure.6.0ACCEPTANCE CRITERIA

6.1API 650

6.2Client specification

7.0REPORTS7.1A leak test report shall be filled out. The test report shall as a minimum, contain the following information:

7.1.1Date of test

7.1.2Client

7.1.3Project

7.1.4Name of operator

7.1.3Acceptance Criteria

7.1.4Test result

The test shall be maintained in accordance with code requirements. Please refer to attachment A

REPORT NO: ATTACHMENT ACLIENT : ITEM INSPECTED :

PROJECT: PROCEDURE NO: TS/VBT/GP/01

ACCEPTANCE CRITERIA: PAGE:

MATERIALCARBON STEELSTAGE OF EXAMINATION

PREPARED EDGE AFTER REPAIR

AS WELDED AS ROLLED

BEFORE/AFTER PWHT BEFORE/ AFTER HYDRO TEST

TEMPERATUREAMBIENT

VACUUM BOX DIMENSION1 FEET X 0.5 FEET

SURFACE PREPARATION GRINDING MACHINING POWER BRUSH

PRESSURE5 BAR (35kpa)

HOLDING TIME5-10 SEC

RESULTS

TS /WO DATE: DATE:

INSPECTED BY:

CLIENTS AUTHORISED REPRESENTATIVE:

VACUUM BOX TESTING REPORT