NO. 2/13, PEENYA INDUSTRIAL AREA, BANGALORE-58

VTPL/HLT/Rev 0

PROCEDURE FOR HELIUM LEAK TESTING OF HYDROGEN OXIDATION SYSTEM

Heavy Water Plant, Kota

MSLD : Mass Spectrometer Leak Detector.

SP : Sniffer Probe

Prepared By

R Sreenivasa PrasadService Engineer - VTPL

Checked/ Reviewed By Approved By

NO. 2/13, PEENYA INDUSTRIAL AREA, BANGALORE-58

VTPL/HLT/Rev 0

1. Scope This procedure is applicable for the helium leak testing of Hydrogen Oxidation System and its components at HWP (Kota)

2. Reference ASME Section V Article 1 and Article 10 Appendix IV

3. Equipment Details Instrument Make: Model:

Detector (Sniffer) ProbeMake: Model:

Calibration Standard:Standard Leak: Make:

Pressure Gauge: Range: Calibration Date:

4. Personal Qualification The operator should be qualified minimum up to Level II of ASNT/ISNT.

5. Calibration of Equipment

Warm Up: The instrument should be turned on and allowed to warm up for the minimum 15 mins. prior to calibrating with the calibrated leak standard.

Calibration: The helium mass spectrometer should be calibrated as per manufacturer’s manual to a sensitivity of at least 10-9 Std cc/sec by calibrated leak.

6. Testing Procedure 6.1 Connect all Rupture Disc, Safety Valves, and Pressure Transmitters & Pressure gauges

to the system as per the test scheme.6.2 Pressurize the system with N2 (Inert Gas) up to 1 bar gauge and raise the pressure by

Helium Gas up to 1.7 bar gauge.

Prepared By

R Sreenivasa PrasadService Engineer - VTPL

Checked/ Reviewed By Approved By

NO. 2/13, PEENYA INDUSTRIAL AREA, BANGALORE-58

VTPL/HLT/Rev 0

6.3 All joints required to be tested should be cleaned with acetone and surface should be free from oil/grease/dust etc.

6.4 All weld & flange Joints should be wrapped with Plastic/masking tape.6.5 Prior to testing, the test pressure shall be held for 4 hrs.6.6 Start the leak detector and calibrate the instrument as per calibration procedure.

Calibration shall be done on every four hours and at the end of the shift or test.6.7 Connect the probe with leak detector and note down the

background readings as well as detection time required by the system to detect the standard leak through sniffer probe.

6.8 Start sniffing the joints by puncturing the masking tape from bottom to top. The probe should be hold in position for time more than the detection time observed during calibration.

6.9 Any unacceptable indication of leak shall be recorded along with joint identification and location of leak and the same shall be marked on the joints with marker also.

6.10 The component shall then be depressurized, and the leak(s) repaired. After repairs have been made, the repaired area or areas shall be retested in accordance with the requirements of this procedure.

7.0 Acceptance Criteria Maximum permissible leak rate are as follows:Weld joints : 1X10-7 Std cc/secFlange/ mechanical joints : 1X10-7 Std cc/sec

8.0 Report Result should be reported in the test report format.

9.0 Post Cleaning After completion of test, masking tape from all the joints should be removed and the joints should be cleaned with acetone.

Prepared By

R Sreenivasa PrasadService Engineer - VTPL

Checked/ Reviewed By Approved By

NO. 2/13, PEENYA INDUSTRIAL AREA, BANGALORE-58

VTPL/HLT/Rev 0

Prepared By

R Sreenivasa PrasadService Engineer - VTPL

Checked/ Reviewed By Approved By