NDBC-8117.pdf

PROCEDURE: NDBC 8117 Rev.-

DATE: 2/12/2009

NDBC STANDARD TEST PROCEDURE

FOR

DART II HULL PRESSURE TEST

NATIONAL DATA BUOY CENTER

JOHN C. STENNIS SPACE CENTER

STENNIS SPACE CENTER, MISSISSIPPI 39529-6000

PROCEDURE: NDBC 8117 Rev. -

REVISIONS

REV DESCRIPTION DATE APPROVED

- Obsoletes ETP 06-049 2/12/2009

J. Wise

ACRONYMS AND ABBREVIATIONS

DART ..................... Deep Ocean Assessment and Reporting of Tsunamis

NDBC ..................... National Data Buoy Center

in. ........................... inch

ID ............................ Inner Diameter

SST ........................ Stainless Steel

NDBC ..................... National Data Buoy Center

NPT ........................ National Pipe Thread

NDBC ..................... National Data Buoy Center

UNF ........................ Unified National Pipe Thread

1.0 PURPOSE

This procedure provides instruction for testing the DART II buoy well for leakage. Successful completion of this procedure is indicated by the application of a green tag to the equipment.

2.0 APPLICATION

This procedure applies to all DART II buoys, and it must be performed in its entirety before the units can be green tagged. This procedure is used for new buoys undergoing initial testing, buoys returned from the vendor after repairs, and any buoy that has returned from a station.

3.0 PREREQUISITES

One blank plug of the buoy faceplate must be drilled and tapped. An air hose quick connector must be installed into this location for the duration of this test.

4.0 DISCUSSION

DART II buoy hulls contain a complex payload of batteries and electronics. The hull of the buoy must therefore be kept dry at all times. This test procedure ensures that the DART II buoy well has no leakage. This test must be run before a DART II buoy can be deployed as a station. The procedure will verify that the faceplate, buoy hatch, and buoy well are intact and functioning properly.

5.0 EQUIPMENT REQUIRED

Air test assembly set including the following as a minimum:

1. 1 manual pressure regulator (0 to -5 psi)

2. Miscellaneous pipe fittings and hose

3. 1 relief valve (automatically relieves pressure greater than 5 psi) (Note: The valve will be non-adjustable and capable of independently reducing the pocket air pressure more rapidly than it can be increased by the air source.)

4. 2 pressure gauges (calibrated, 0 to 5 psig minimum range, 0 to 12 psig maximum range, readable to 0.125 psig or better)

5. 2 air pressure valves (manual, 150 psig)

Roll of Thread Sealant Tape

Pressure Gauge

Soap solution for leak detection

6.0 SAFETY

An improper air test procedure can result in extensive structural damage and serious injury to test personnel. Testing should always be performed by qualified personnel using proper equipment. Any procedural questions will be resolved before the start of testing.

Personnel performing the procedure should be familiar with the NTSC/NDBC Safety and Accident

Prevention Program Plan and the NASA Safety Manual HDB 1700.3.

7.0 INSTRUCTIONS

7.1 ADMINISTRATIVE SECTION

Complete the administrative section of the data sheet.

7.2 TESTING

7.2.1 The test will be conducted in the ambient environment in an area shaded from direct sunlight and rainfall.

7.2.2 Upon detection of leakage, testing will be suspended until each leak is repaired, the failure documented, and testing resumed at the discretion of the test director. This test procedure may be “redlined” as necessary, during testing and the test continued at the discretion of the test director. Any such deviations from prescribed procedure will be noted on the test data sheet in the comments section.

7.2.3 Record the serial numbers and calibration due dates for all test equipment on the test acceptance sheet.

7.2.4 Remove one of the faceplate dummy plugs from the faceplate of the buoy. Install the quick connector into the faceplate. Typically, this is accomplished by using an adaptor made from a faceplate dummy plug. An adaptor can be made by drilling and tapping a faceplate dummy plug to accept the quick connector.

7.2.5 Ensure that the buoy hatch and faceplate are secure to keep outer air from intruding during the pressure process.

7.2.6 Setup test equipment according to figure 1.

Figure 1- Equipment Setup

7.2.7 Pressurize the buoy compartment to 1½ ±¼ psig.

7.2.8 After pressurizing the compartment, shut off the compressed air supply, and leak-check all access covers, seals, and welded joints using liquid soap solution.

7.2.9 Once the compartment pressure has stabilized, record the pressure. Annotate the data sheet.

7.2.10 Record the final pressure after 15 minutes have elapsed. The compartment pressure must not drop by more than ⅛ psig in 15 minutes. Annotate the data sheet.

7.2.11 Locate and repair any leakage and retest the compartment. Leakage due to defects in plating or welds will be repaired in accordance with NDBC-8031.

7.2.12 Upon completion, replace the faceplate blank plug using Teflon tape.

7.3 EMERGENCY SECURE SEQUENCE

7.3.1 Shut off compressed air supply.

7.3.2 Open the manual valve to the vent.

7.4 APPROVAL

7.4.1 Complete applicable approval information on the datasheet.

7.4.2 Submit to NTSC QA for inspection.

Pressure Gauge

Pressure Gauge

5 PSI Relief Valve

Valve

To Buoy

Manual Pressure Regulator

Valve

Compressed Air Supply

8.0 DATASHEET

NDBC STANDARD TEST PROCEDURE FOR

Administrative Section Equipment Part Number NDBC # CAL DUE DATE

Buoy Hull Number

TESTING

Test Section

Step No.

Description Measured P / F

7.2.9 Applied pressure (1½ ±¼ psig)

___________PSIG

N/A

7.2.10 Pressure remained steady for 15 minutes

___________PSIG

pressure remains within ± 1/2 psig for the full 15 minutes

NOTES:

Approval Section

OVERALL EVALUATION: PASS / FAIL

Test Conductor: Date:

NTSC QA: Date: