PWS_MUTC Flask Inspection.docx

MUTC FLASK MAINTENANCE

Performance Work Statement

1. GENERAL

1.1 BACKGROUND

1.1.1 Military Sealift Command requires inspection service for 10 Air Flasks located at Military Sealift Commands Underway Replenishment Training Center (MUTC), Joint Expeditionary Base Little Creek-Fort Story (JEBLC). Vendor must complete an ultrasonic test of each flask in accordance with Technical Manual S9086-SY-STM-010, COMPRESSED AIR PLANTS AND SYSTEMS Appendix A and Appendix C and provide certified service technicians. All work shall be performed in accordance with the technical manual practices and procedures included herein.

1.1.2 All testing shall be performed by trained technicians.

1.1.2.1 Material Deficiencies shall be reported to the Contracting Officer Representative (COR).

1.1.2.2 The contractor is responsible for providing all materials and services required for the successful completion of this PWS.

1.2 OBJECTIVES

1.2.1 Under this contract, all services shall be performed by authorized technical representatives who are certified in accordance with the American Society for Nondestructive Testing.

1.2.2 All work shall be performed in accordance with S9086-SY-STM-010, COMPRESSED AIR PLANTS AND SYSTEMS (Appendix “A” and “C”) Technical Manual practices and procedures.

2. PLACE AND OF PERFORMANCE

2.1. Place of Performance: Military Sealift Command (MSC), 1142 5th Street, Virginia Beach, VA 23459 / JEBLC.

2.2. Period of Performance: All inspections shall be completed within 14 calendar days from awarded contract. The final report shall be submitted to MSC’s technical POC within 7 calendar days of inspection completion.

3. SPECIFIC TASKS:

3.1 Appendix A and Appendix C of Technical Manual S9086-SY-STM-010, COMPRESSED AIR PLANTS AND SYSTEMS (included herein) are to be used as reference for the work being contracted.

3.2 Service provider is to perform ultrasonic testing in accordance with previously referenced material.

3.3 Work hours will be between the hours of 0700 and 1500 Monday – Friday at the MSC UNREP Training Center 1142 5th Street Bldg. 3525 JEB Little Creek Virginia Beach, VA 23459.

3.4 Service provider shall submit a condition report on each air flask to the COR. These condition reports shall identify the overall condition of each tank and list all deficiencies noted.

3.5 Provide this service with a capable, certified technician.

3.6 DELIVERABLES

A finalized report detailing found deficiencies and issues.

3.7 TECHNICAL MANUALS

S9086-SY-STM-010, COMPRESSED AIR PLANTS AND SYSTEMS Appendix A and Appendix C

4. PLACE OF PERFORMANCE

Services will be accomplished at the Government site, 1142 5th Street, Virginia Beach, VA 23459. The contractor shall comply with any necessary Naval Base Security and insurance requirements. Contractor must have a Real ID to be granted a pass for base access. The Government POC will help with paperwork to receive a base pass for the duration of the work.

5. AUTHORIZED CHANGES BY THE CONTRACTING OFFICER

The Contracting Officer is the only person authorized to approve changes to any of the requirements of this contract and notwithstanding provisions contained elsewhere in this contract, said authority remains solely the Contracting Officer’s. In the event the Contractor effects any change at the direction of any person other than the Contracting Officer, the change will be considered to have been made without authority, and no adjustment will be made in the contract price to cover any increase incurred as a result thereof.

6. CONTRACTOR IDENTIFICATION

6.1 Contractor employees must be clearly identifiable while on Government property by wearing appropriate badges.

6.2 Contractor personnel and their subcontractors must identify themselves as Contractors or subcontracts during meetings, telephone conversations, in electronic messages, or correspondence related to this Contract.

7. LICENSES, PERMITS, AND PRECAUTIONS

The Contractor shall, at the Contractor’s expense, be responsible for obtaining any necessary licenses and permits, and for complying with any applicable laws, codes, and regulations, in connection with the performance of work. Further, the Contractor is responsible to ensure that proper safety and health precautions are taken to protect the work, the workers, the public, and the property of others.

8. Deliverables

APPENDIX A

REQUIREMENTS FOR ULTRASONIC INSPECTION OF HIGH-PRESSURE COMPRESSED GAS FLASKS

551-A.1 SCOPE.

551-A.1.1 These requirements apply to the ultrasonic examination of compressed gas flasks. An ultrasonic inspection is performed to detect wall thinning, axial cracks and circumferential cracks in the main body of the flask. Cylindrical flask hemispherical heads are ultrasonically inspected for wall thinning. SAF hemispherical heads and pressure boundary welds are ultrasonically inspected for wall thinning and soundness.

551-A.2 PROCEDURE.

551-A.2.1 Ultrasonic inspection procedures shall be prepared in accordance with this document. The procedures shall meet the requirements of NAVSEA T9074-AS-GIB-010/271 (except as modified herein) and be qualified in accordance with NAVSEA T9074-AS-GIB-010/271.

551-A.3 PERSONNEL.

551-A.3.1 Inspection personnel shall be certified in accordance with NAVSEA T9074-AS-GIB-010/271 and be thoroughly familiar with the requirements of this document.

551-A.3.2 Inspection personnel performing Appendix B discontinuity sizing measurements shall be qualified and certified in accordance with Appendix B.

551-A.4 EQUIPMENT.

551-A.4.1 Ultrasonic equipment shall meet the requirements of NAVSEA T9074-AS-GIB-010/271.

551-A.4.2 Ultrasonic reference calibration standards shall meet the requirements of NAVSEA T9074-AS-GIB-010/271. A block is required for thickness measurements, circumferential crack detection and axial crack detection. For cylindrical flasks, circumferential and axial crack detection shall employ calibration standards with calibration reflectors consisting of 3 percent I.D. and O.D. notches. A separate calibration standard is not required for the three inches of scanning performed on each of the hemispherical heads (different curvature). SAF base material circumferential and axial crack detection and weld inspections for detection of cracks internal to the SAF weld volume shall employ calibration standards with calibration reflectors consisting of 3/64 side drilled holes and meet the weld standard requirements of NAVSEA T9074-AS-GIB-010/271. All calibration standards shall be fabricated from a piece of a scrapped flask or an acoustically similar material as defined in NAVSEA T9074-AS-GIB-010/271. The calibration block shall have a surface finish and curvature similar to the flasks to be inspected, except, for flasks greater than 24 inches in diameter, flat reference blocks may be used in conjunction with curvature correction compensation when approved by NAVSEA. An 18-inch diameter flask and a 20-inch diameter flask are considered to have similar curvatures (see paragraphs 551-A.6.2 and 551-A.6.3 for exceptions for painted surfaces).

551-A.4.3 The ultrasonic transducer for thickness measurements may be either the single element or dual element design. The transducer for shear wave inspection shall have an active element size of not greater than 1 inch, with a nominal frequency of 2.25 to 5 MHz. For shear wave base material inspection, the transducer shall be affixed to a suitable wedge designed to produce shear waves in the material at 45 degrees. For weld inspection, the transducer inspection angles shall be in accordance with the weld inspection requirements in NAVSEA T9074-AS-GIB-010/271, or as approved by local Test Examiners in special cases to obtain meaningful results. All shear wave angles shall be within 3 degrees of the nominal transducer angle.

551-A.4.4 Ultrasonic couplant shall be in accordance with NAVSEA T9074-AS-GIB-010/271. Oil or oil-based couplants shall not be used without approval of the shipyard code responsible for cleaning and painting the flasks. The couplant used for calibration shall be used for inspection. Couplant shall be removed upon completion of the test.

551-A.5 SURFACE PREPARATION.

551-A.5.1 ULTRASONIC INSPECTION. The examination surface shall be free of loose or bubbled paint, grease, dirt and any other foreign material that might interfere with scanning. Tightly adhering paint does not require removal. Average surface roughness shall be 250 RMS or better. Surface waviness shall not interfere with search unit contact. Reduce pressure in flask to 150 psig maximum before using power tools such as sanders, needle guns, or sandblasting to remove paint. Use of grinders to remove paint from flasks is prohibited.

Particles of removed paint and debris can pose a fire hazard. Maintain cleanliness of the work area to reduce this risk. Provide adequate ventilation in enclosed spaces and use Class II dust ignition proof lights, or better.

551-A.6 ULTRASONIC CALIBRATION.

551-A.6.1 GENERAL. The inspection system shall be calibrated prior to each scanning session or shift, at any equipment change (instrument, search unit, cable, etc.) and at the completion of the inspection. If the calibration check indicates that recalibration is required, all areas inspected since the last valid calibration shall be re-inspected.

551-A.6.2 THICKNESS. For thickness measurements through paint, a multiple echo technique shall be used. Other methods for thickness measurements through paint may be utilized, if approved by the NAVSEA authorized representative.

551-A.6.3 PAINT COMPENSATION. For shear wave inspection through paint, an attenuation correction is required to compensate for the effect of the paint on the test sensitivity. A comparison shall be made between the part to be inspected and the specific reference standard to be used. The comparison shall be based on a two transducer pitch-catch shear wave signal using a single full skip obtained from similar geometrical areas on the reference standard and the flask. The transducers used for the attenuation check shall be the same type, frequency and angle as that which will be used for inspection. A smaller size transducer may be used when required to peak the single full skip signal. A minimum of three random locations shall be evaluated on each flask. Compensation for paint attenuation, measured to the nearest dB, shall be added to the instrument gain after the conventional calibration is performed on the unpainted calibration block. The most attenuative area measured on the flask shall be used to determine the correction value. Alternatively, the paint compensation value may be determined by removing paint from three random areas on each flask and performing the shear wave pitch catch comparison described above using the painted and unpainted adjacent areas. Other alternative approaches to perform paint compensation shall be approved by NAVSEA.

551-A.6.4 SHEAR WAVE (CYLINDRICAL FLASKS). Calibration for inspection of base material shall be performed in accordance with the ring forging shear wave calibration requirements in NAVSEA T9074-AS-GIB-010/271 (i.e., inspection is performed between the 1/2 skip and 1-1/2 skip). The Amplitude Rejection Level (ARL) shall be established at 80 percent of full screen height, and the Disregard Level (DRL) shall be 1/2 the ARL.

551-A.6.5 SHEAR WAVE (SAFs). Calibration for shear wave inspection of SAFs shall be performed in accordance with the butt weld calibration requirements (Class 1) in NAVSEA T9074-AS-GIB-010/271.

551-A.7 CYLINDRICAL FLASK THICKNESS SCANNING.

551-A.7.1 Thickness measurements shall be made at the intersection of a grid drawn over the entire surface of the flask, including the heads. Flasks smaller than 10 cu ft shall have a 6 inch by 6 inch grid (with 3 inch tolerance on inspection points to clear obstructions). Flasks 10 cu ft and larger shall have a 12 inch by 12 inch grid (with 6 inch tolerance on inspection points to clear obstructions). The grid shall be oriented to facilitate measurement at a minimum of 90 percent of the inspection points.

551-A.7.2 Any area of visible corrosion on the flask shall be also measured near the center of the area. Localized areas of wall thinning shall be continuously scanned to their extremities to ensure that the deepest area of thinning has been measured.

551-A.8 CYLINDRICAL FLASK SHEAR WAVE SCANNING.

Shear wave inspections shall be performed over 60 percent of the entire flask body in both the axial and circumferential direction, including three inches, or the maximum extent possible, into each cylindrical flask hemi-spherical head (i.e., three inches toward the neck from the point where the flask body first curves to form the head). This 60 percent should include as much as is practical of the bottom third of the cylindrical flask’s cylindrical section with the remainder taken as a random sample. Scanning is only required in one axial direction and one circumferential direction. Continuous scanning with a minimum of 25 percent overlap shall be used.

551-A.9 SAF THICKNESS SCANNING.

For SAFs, perform UT thickness measurements in the following locations (see Figure 551-A-1):

551-A.9.1 LOW POINT(S). Intersection of a 4 x 4 inch maximum grid pattern over a four square foot area (2 feet x 2 feet with 49 points) with the center of a the grid located at the flask low points(s), (generally centered on area where fluid will puddle). Two low points exist on SAFs having the longitudinal axis installed horizon-tally and one low point exits for SAFs installed on an angle. Thickness measurements are not required for the points that lie on tapered sections, penetration inserts, under foundation rings and stiffeners and their attachment welds.

551-A.9.2 HIGH STRESS AREAS ON AND ADJACENT TO CYLINDER. Single row of points spaced 6 inches (tolerance on 6 inches is + / - 1/2 inch) apart around the flask circumference on each hemispherical head adjacent to the taper and on the cylindrical section adjacent to the foundation ring that is welded into the bulk-head. This will result in three rows of points (one on each head and one on the cylinder). Where a row overlaps the 4 x 4 inch grid, the points spaced 6 inches apart are not required to be measured for thickness.

551-A.9.3 HIGH STRESS AREAS OF PENETRATION INSERTS. Two concentric circles spaced 6 inches apart, with inspection points spaced 6 inches apart within each row, around each penetration insert (end plugs, supply discharge plug and drain plug). The inner circle shall be located beyond the taper of the penetration at or directly adjacent the penetration weld. Where the points overlap other rows or grid points, only one measurement at that location is required.

551-A.9.4 DEFECT LOCATIONS. Defect locations found during the visual inspection (locations having a defect 1/16 inch or more in depth).

551-A.9.5 NOTES. The space may be less than 6 inches at the end/start of a row. The grid or row points may be staggered between rows or longitudinal lines.

Figure 551-A-1. UT Thickness Measurements Locations Examples

S9086-SY-STM-010

551-A-10

551-A.10 SAF WELD AREA SHEAR WAVE SCANNING.

Shear wave inspections shall be performed for 100 percent, as practical, of SAF welds and adjacent heat affected zones (HAZ) that fall within areas defined Figures 551-A-1 and 551-A-4 and Tables 551-A-1 through 551-A-3. Areas of base material in these locations, outside of the HAZ, shall be inspected per paragraph 551-A.11. The term as practical is to allow for the taper portion near the welds and areas under attachments that cannot be inspected. Portions of the tapered section that can be scanned shall be scanned when practical. Scanning shall be in accordance with the Class 1 butt weld requirements of NAVSEA T9074-AS-GIB-010/271. The minimum and maximum depth of all reportable discontinuities shall be recorded as follows:

a. To determine the minimum depth of a discontinuity, maximize the indication amplitude and scan toward the discontinuity. Record the depth of the signal at the point where the indication begins to drop rapidly toward the baseline.

b. This operation shall be repeated while scanning away from the discontinuity to determine its maximum depth.

When performing SAF weld inspections through paint, all weld areas shall be located and plotted, including the longitudinal weld(s) in the cylindrical SAF section. Methods such as eddy current or removing paint and etching should be utilized to ensure that weld areas are properly identified.

551-A.11 SAF BASE MATERIAL SHEAR WAVE SCANNING.

Shear wave inspections shall be performed over 100 percent, as practical, of SAF base material in areas defined in Figures 551-A-1 and 551-A-4 and Tables 551-A-1 through 551-A-3 (outside of the above defined weld and HAZ areas). The term as practical is to allow for the taper portion near welds and areas under attachments that cannot be inspected. Portions of the tapered section that can be scanned shall be scanned when practical. In addition to these high stress areas, base material inspection shall be performed over a 2 foot x 2 foot section (four square foot area) with the center located at the flask low point(s) (generally centered on the area where fluid will puddle). Two low points exist on SAFs having the longitudinal axis installed horizontally and one low point exists for SAFs installed on an angle. Scanning of base material is only required in one axial direction and one circumferential direction. Continuous scanning with a minimum of 25 percent overlap shall be used.

Figure 551-A-2. Typical Spherical Air Flask Inspection Zones with Access Plugs (See Tables 551-A-1, 2, and 3)

Figure 551-A-3. Typical Spherical Air Flask Inspection Zones End View Showing Adapter Plates (See Tables 551-A-1, 2, and 3)

Figure 551-A-4. Typical Spherical Air Flask Inspection Zones with Manway (See Tables 551-A-1, 2, and 3)

Feature - Inspection Zone

A - Drain line side inspection/maintenance penetration

B - Manway-Spherical Transition

Longitudinal distance from external manway face

C - Spherical-Cylindrical Transition - Drain Side

Longitudinal distance from drain line side face of drain line side circumferential ring

D - Flask wall under circumferential Ring - Drain Side

Distance on each side of circumferential ring, also inspect under ring to maximum extent practical

E - Flask wall under circumferential Ring - Center N/A

F - Flask wall under circumferential Ring - Supply Side

Distance on each side of circumferential ring, also inspect

G - Spherical-Cylindrical Transition - Supply Side

Table 551-A-1. SEAWOLF Class Inspection Zones - Continued

Longitudinal distance from supply side face of supply side circumferential ring

H - Supply-Discharge Line

I - Supply side inspection/maintenance penetration

J - Drain Line

K - Flask Wall Under Longitudinal Stiffener

Distance on each side of adapter plate (stiffener), also inspect under stiffener to maximum extent practical

L - Longitudinal weld on cylinder part of flask (not shown), Inspect weld and HAZ

Table 551-A-2. SSN 688 Class Inspection Zones

Feature - Inspection Zone

A - Drain line side inspection/maintenance penetration

B - Manway-Spherical Transition N/A

C - Spherical-Cylindrical Transition - Drain Side

Longitudinal distance from drain line side face of drain line side circum-ferential ring

D - Flask wall under circumferential Ring - Drain Side NA

E - Flask wall under circumferential Ring - Center

Distance on each side of circumferential ring, also inspect under ring to maximum extent practical

F - Flask wall under circumferential Ring - Supply Side NA

G - Spherical-Cylindrical Transition - Supply Side

Longitudinal distance from supply side face of supply side circumferential ring

Table 551-A-2. SSN 688 Class Inspection Zones - Continued

H - Supply-Discharge Line

I - Supply side inspection/maintenance penetration

J - Drain Line

K - Longitudinal Stiffener

Distance on each side of adapter plate (stiffener), also inspect under stiff-ener to maximum extent practical

L - Longitudinal weld on cylinder part of flask (not shown), Inspect weld and HAZ

Table 551-A-3. SSN 774 Class Inspection Zones

Feature - Inspection Zone

A - Drain line side inspection/maintenance penetration

B - Manway-Spherical Transition NA

C - Spherical-Cylindrical Transition - Drain Side

Longitudinal distance from drain line side face of drain line side circumferential ring

D - Flask wall under circumferential Ring - Drain Side

Distance on each side of circumferential ring, also inspect

E - Flask wall under circumferential Ring - Center N/A

F - Flask wall under circumferential Ring - Supply Side

Distance on each side of circumferential ring, also inspect

G - Spherical-Cylindrical Transition - Supply Side

Longitudinal distance from supply side face of supply side circumferential ring

Table 551-A-3. SSN 774 Class Inspection Zones - Continued

H - Supply-Discharge Line

I - Supply side inspection/maintenance penetration

J - Drain Line

K - Flask Wall Under Longitudinal Stiffener

Distance on each side of adapter plate (stiffener), also inspect under stiffener to maximum extent practical

L - Longitudinal weld on cylinder part of flask (not shown), Inspect weld and HAZ

551-A.12 ACCEPTANCE CRITERIA.

551-A.12.1 ULTRASONIC THICKNESS INSPECTION. Flasks with a measured wall thickness below the required minimum wall thickness listed in Table 551-A-4 shall be rejected. Rejectable areas shall also be evaluated per Appendix B to determine if the rejectable condition is the result of a thinned area or due to a lamination in the wrought material. Refer to Table 551-4-12 for information on older, obsolete flasks.

Table 551-A-4. Minimum Allowable Wall Thicknesses for Air Flasks

Diameter (Inches)

Minimum Wall Thickness (Inches)

(84 cu ft)

2.94 Cylindrical Section

1.74 Hemispherical Section

75.25 OD2

(167 cu ft)

3.94 Cylindrical Section

2.30 Hemispherical Section

SSN 21 & SSN 774

Class SAFs: D-306-01 550-7410313 100-7285186

(80 cu ft)

3.19 Cylindrical Section

1.92 Hemispherical Section

74.38 OD2

(160 cu ft)

3.94 Cylindrical Section

2.30 Hemispherical Section

87.50 OD2

(245 cu ft)

4.69 Cylindrical Section

2.69 Hemispherical Section

1MIL-F-24032 flasks are fabricated of K-monel and are intended for removal of KOH (potassium hydroxide) carryover from oxygen generators. MIL-F-24032 flasks are included here to make the table complete and com-prehensive.

2The outside diameter (OD) listed for the spherical flasks is for the cylindrical section.

551-A.12.2 ULTRASONIC SHEAR WAVE INSPECTIONS. (CYLINDRICAL AND SAF BASE MATERIAL).

Any base material discontinuity with a maximum amplitude that exceeds the Amplitude Rejection Level (ARL), or exceeds the Disregard Level (DRL) with a length over 3 inches, shall be evaluated in accordance with Appendix B. Results of the inspections shall be forwarded to NAVSEA for disposition.

551-A.12.3 ULTRASONIC SHEAR WAVE INSPECTIONS (SAF WELDS). Weld and heat affected zone dis-continuities that exceed the Class 1 criteria of MIL-STD-2035A shall be reported. The minimum and maximum depths of these discontinuities shall be reported per paragraph 551-A.10. Results from volumetric weld inspections shall be supplied to NAVSEA for review as soon as possible. Discontinuities selected by NAVSEA shall then be characterized and sized in accordance with a NAVSEA approved ultrasonic discontinuity characterization and sizing procedure, and reported to NAVSEA for disposition.

551-A.13 RECORDING AND REPORTING.

551-A.13.1 A separate flask inspection report prepared in accordance with NAVSEA T9074-AS-GIB-010/271 shall be completed for each flask inspected. Flasks shall be identified as defined by the shipyard design code. Reference lines or a grid shall be established to accurately record discontinuity position. The same reference lines shall be used for the thickness measurements, shear wave crack detection scans and crack sizing inspections (if performed). (For submarines, the certified Task Group Instruction (TGI) process satisfies the recording and reporting requirements herein.)

551-A.13.2 The following information shall be included in the report:

a. Hull number.

b. Flask identification, size and type.

c. Ultrasonic procedure(s) identification and revision number.

d. Inspector’s name, level and signature.

e. Date of each inspection.

f. Type of material inspected.

g. Equipment description and serial numbers (ultrasonic instruments).

h. Ultrasonic transducer manufacturer, frequency, size, angle and serial number.

i. Ultrasonic couplant used.

j. Ultrasonic calibration standard serial numbers.

k. If ultrasonic inspection is performed through paint, describe the specific technique used to compensate for paint (thickness measurement and shear wave inspections).

l. Assign a unique number to each reportable discontinuity.

m. Report the specific location of each discontinuity on the flask. Reporting shall be such that the area can be relocated after the flask is painted. Unless otherwise specified by the shipyard design code, report all discontinuities using the inboard, top point of the flask where the hemispherical head just begins to form as a standard reference point. Report all discontinuities in the body of the flask from this point in terms of (1) inches down the flask along the inboard surface of the flask and (2) inches around the circumference of the flask (measured in a counter-clockwise direction, as viewed from the top of the flask). For discontinuities in the head region, skirt attachment weld, or SAFs use a sketch to report the locations. Mark the location of the standard reference point described above on the sketch. For SAFs, a secondary reference point may be used (vice the reference point established for the flask) to report the locations in lieu of the sketch, particularly for indications in welds. The location of the secondary reference point shall be accurately identified on the inspection report.

n. Record the length of the discontinuity and the method used to measure the length (e.g., ultrasonically mea-sured using a 6 dB drop technique).

o. Record the orientation of the discontinuity (e.g., relative to the flask axis or weld direction).

p. Record the indication’s ultrasonic peak amplitude relative to reference level. Amplitude shall be reported in percentage of screen height for indications with peak amplitudes less than the reference level, and dB above reference level for indications at or exceeding the reference level.

q. Enter the location of the discontinuity from the scanning surface (for ultrasonically detected discontinuities).

r. Enter the characterization of the discontinuity, as determined from Addendum A, Ultrasonic Discontinuity Characterization Requirements. Add notes and sketches to aid in characterizing the discontinuity (open to ID, open to OD, detected by inspection, etc.).

s. All ultrasonic thickness measurements including grid locations.

The reportable SAF weld volume indications sized for through wall height to report the minimum depth and maximum depth shall be supplied to NAVSEA for review as soon as possible prior to the above formal report to allow time for discontinuities to be selected by NAVSEA then be characterized and sized by the test facility for NAVSEA disposition.

APPENDIX C

REQUIREMENTS FOR NONDESTRUCTIVE INSPECTION OF IN-SERVICE AIR RECEIVERS

551-C.1 SCOPE.

This instruction contains the standard requirements to be used for the recertification of air receivers (in-place) manufactured in accordance with MIL-T-15301, using non-destructive testing techniques instead of hydrostatic testing.

551-C.2 REFERENCE DOCUMENTS.

The following references form a part of this procedure to the extent specified herein.

a. MIL-T-15301, Tanks, Pressure 600 P.S.I. Gage Working Pressure, Naval Shipboard Use.

b. T9074-AS-GIB-010/271: Requirements for Nondestructive Testing Methods.

c. S9074-AR-GIB-010/278: Requirements for Fabrication Welding and Inspection and Casting Inspection and Repair for Machinery, Piping and Pressure Vessels.

d. MIL-STD-2035: Non-destructive Testing Acceptance Criteria.

551-C.3 PROCEDURE.

551-C.3.1 Magnetic Particle Test (MT), Dye Penetrant Test (PT), Ultrasonic Test (UT) and Visual Test (VT) procedures shall be prepared in accordance with this appendix. The procedure shall be in accordance with reference

(b) (except as modified herein) and qualified in accordance with reference (b).

551-C.4 QUALIFICATION REQUIREMENTS.

Inspection personnel shall be certified in accordance with reference (b) and be thoroughly familiar with the requirements of this appendix.

551-C.5 EQUIPMENT.

551-C.5.1 Ultrasonic equipment shall meet the requirements of reference (b). As a minimum, ultrasonic equipment shall be of the pulse-echo type and have and have an A-scan display. It is also recommended that a digital thickness readout be incorporated in the unit. The transducer for thickness measurements may be either the single element or dual element design.

551-C.5.2 Ultrasonic couplant shall be used in accordance with reference (b). Oil or oil-based couplants shall not be used without prior approval. The couplant used for calibration shall be used for inspection. Couplant shall be removed upon the completion of the test.

551-C.5.3 Magnetic particle equipment shall meet the requirements of reference (b). An AC yoke shall be used to prevent arc strikes.

551-C-2

551-C.6 SAFETY PRECAUTIONS.

551-C.6.1 Always wear safety glasses when performing a magnetic particle inspection.

551-C.6.2 Prior to connecting the magnetic particle inspection unit to the power source, ensure that all unit cables are visually inspected for damage.

551-C.7 SURFACE PREPARATION.

551-C.7.1 Prior to the ultrasonic inspection, the examination surface shall be free of loose or bubbled paint, grease, dirt and any other foreign material that might interfere with the inspection. Tightly adhering paint does not require removal. Average surface roughness shall be 750 RMS or better. Surface waviness shall not interfere with search unit contact.

551-C.7.2 Prior to the magnetic particle inspection, all weld surfaces shall be dry, free of dirt, oil, grease, paint, scale or any other contaminates which might interfere with the proper distribution and concentration, or with the intensity, character or definition of magnetic particle indications. With the exception of undercuts which are within the specification allowances, the contour of the welds shall blend smoothly and gradually into the base metal. Weld surface irregularities shall be removed to the extent that they will not interfere with the interpreta-tion of the test results.

551-C.7.3 All inspection surfaces shall meet the requirements of reference (b) (which includes the removal of paint). Reduce pressure in flasks to 150 psig maximum before using power tools such as sanders, needleguns, or sandblasting to remove paint. Use of grinders to remove paint from flasks is prohibited.

Particles of removed paint and debris can pose a fire hazard. Maintain cleanliness of the work area to reduce this risk. Provide adequate ventilation in enclosed spaces and use Class II dust ignition proof lights, or better.

551-C.8 TEST PROCEDURE.

551-C.8.1 EXTERNAL VISUAL EXAMINATION. Upon successful completion of the magnetic particle test, the inspector shall conduct an external visual examination. The inspector shall record any deformities in the shape of the receiver and for any other defects such as cracks, blisters, pitting, bulges, deterioration of welded joints or other surface defects that could reduce the safe operation of the receiver.

551-C.8.2 INTERNAL VISUAL EXAMINATION.

555-C.8.2.1 Internal visual examination will require the air system be tagged out in order to open up the receiver. All tag out procedures shall be accomplished by ship’s force. Under no circumstances shall the inspector tag out any piece of equipment. Once the system is tagged out, bleed down the air system and receiver by opening up the drains on the receiver. Once again, this shall be accomplished by Ship’s Force.

555-C.8.2.2 After bleed down, an inspection port shall be opened on the receiver. If the receiver has a manhole/ handhole, it shall be opened first and all internal observations shall be made using this port. If the receiver does not have a manhole/handhole port, remove a flanged piping connection on the receiver. For best results remove a flange on the top of the receiver. The inspector may need to remove more than one flange connection on the receiver in order to view all the welds and internal surfaces.

555-C.8.2.3 If the internal exam will be accomplished through flanged connections, the inspector shall insert a flexible borescope into all opened flange connections to determine the interior condition of the receiver. If the inspector will be inspecting the receiver through the manhole, then a flashlight and mirror will be suitable.

555-C.8.2.4 During the internal exam, the inspector shall pay particular attention to the welds and the overall condition of the receiver. All observations shall be recorded. All welds shall be examined for discontinuities (i.e. cracks) and general condition. The entire interior surface shall be inspected for corrosion, pitting or blistering or peeling of the protective coating. Also, inspect for any signs of moisture in the receiver. This could be in the form of standing water or water marks on the sides of the receiver.

555-C.8.2.5 If the interior surfaces of the receiver fail the visual exam (i.e. heavy corrosion or the protective coating is blistering) the receiver shall be cleaned and represerved in accordance with paragraph 551-4.7.2.6.

555-C.8.2.6 Upon completion of internal visual exam and replacement of any software, the receiver shall be reassembled, tags removed (by ship’s force) and the air system put back on-line.

551-C.8.3 MAGNETIC PARTICLE AND DYE PENETRANT WELD INSPECTION. For carbon steel receivers, the inspector shall perform a magnetic particle test. The MT test shall always be administered first to avoid any contamination from the UT couplant. The MT test shall be performed in accordance with the inspection activity’s approved procedure, which shall be in accordance with reference (b). The MT inspection shall be performed in two directions with an AC yoke on all the external weld surfaces on the receiver. A typical receiver will have two end cap welds, a seam weld and a number of welded connections (i.e. handholes, drains, inlet/out-let connections, feet, etc.).

555-C.8.3.1 Weld Inspection Inspector shall inspect a minimum of 90% of the total weld length. Anything less than 90% shall be documented for submittal of a Departure from Specification or for submittal to the LCM for evaluation and disposition.

555-C.8.3.2 Dye Penetrant Test (PT). For nonferrous receivers, inspector shall perform a PT. The PT shall be performed in accordance with the inspection activity’s approved procedure, which shall be in accordance with reference (b). The PT inspection shall be performed on the entire external weld surface on the receiver. A typical receiver will have two end cap welds, a seam weld and a number of welded connections (i.e., handholes, drains, inlet/outlet connections, feet, etc.). Inspector shall inspect a minimum of 90% of the total weld length.

551-C.8.4 ULTRASONIC THICKNESS EXAM. The UT inspection system shall be calibrated prior to each inspection session or shift, at any equipment change (instrument, transducers, cables, etc.) and at the completion of the inspection. If the calibration check indicates that recalibration is required, all areas inspected since the last valid calibration shall be re-inspected.

555-C.8.4.1 For thickness measurements through paint, either a multiple echo technique shall be used or the thickness calibration standard shall be painted with a thickness of paint of a similar paint system equal to the average thickness of the paint on the receiver under inspection, plus or minus 0.005 inches. Establish the average thickness to apply to painted calibration standards by taking a minimum of five paint thickness measurements at random locations on each receiver.

555-C.8.4.2 Thickness measurements shall be made at the intersections of a 6 inch by 6 inch grid over the entire surface of the receiver, including the heads. Any area of visible corrosion on the receiver shall be measured near the center of the area. Localized areas of wall thinning shall be continuously scanned to their extremities to ensure that the deepest area of thinning has been measured.

555-C.8.4.3 The inspector shall make a sketch of each receiver similar to Figure 551-C-1 detailing all UT thickness locations and each sketch should correspond to a UT data sheet, similar to the data sheet in Table 551-C-1.

Table 551-C-1. UT Data Sheet

REMARKS:

Figure 551-C-1. Low Pressure Air Receiver UT Thickness Locations

551-C.8.5 REPAINT WELDED SURFACES. All exterior welded surfaces which had paint removed shall be repainted using the same paint scheme as the surrounding structure.

551-C.9 ACCEPTANCE CRITERIA.

551-C.9.1 ULTRASONIC THICKNESS INSPECTION. Receivers with a measured wall thickness below the required minimum wall thickness shall be rejected. Minimum wall thickness for the heads and shell shall be determined by the receiver detail drawing. As stated in paragraph 551-4.7.2.5.2, if the receiver detail drawing does not provide a minimum wall thickness allowance, minimum wall thickness for recertification shall be 90% of the original specified material thickness. However, if the receiver detail drawing is not available, the minimum wall thickness for the heads and shell shall be determined using the formulas in reference (a). Once this value is determined, the minimum allowable wall thickness shall be 90% of the calculated value. Any air receiver with a working pressure greater than 400 psig is considered a Class 1 receiver. Any receiver with a working pressure of 400 psig or less is considered a Class 2 receiver.

555-C.9.1.1 Receivers which are rejected due to below minimum wall thickness should be considered for weld repair in accordance with reference (c).

551-C.9.2 MAGNETIC PARTICLE WELD INSPECTION. All acceptance criteria for the welds inspected shall be in accordance with reference (d). As outlined in reference (c), welds on air receivers with a working pressure greater than 400 psig shall be considered Class 1 welds and welds on air receivers with a working pressure of 400 psig or less shall be considered Class 2 welds.

551-C.9.3 VISUAL INSPECTION, INTERNAL. All acceptance criteria for internal visual inspection of the welds shall be in accordance with reference (d). As outlined in reference (c), welds on air receivers with a working pressure greater than 400 psig shall be considered Class 1 welds and welds on air receivers with a working pressure of 400 psig or less shall be considered Class 2 welds. In addition, minor rust (i.e. surface rust) on the internal surface of the receiver is acceptable. However, if heavy corrosion (i.e. rust flaking off) or heavy pitting is present in the receiver, then determine remaining wall thickness and weld repair, if required, and represerve.

551-C.10 RECORDING AND REPORTING.

An air receiver inspection report shall be prepared in accordance with reference (b). The following information shall also be included in the report:

a. Ship Name and hull number.

b. Receiver identification, size and type.

c. Procedure identification.

d. Inspector’s name, level and signature.

e. Date of the inspection.

f. Type of material inspected.

g. Equipment description and serial numbers (UT instruments and MT equipment).

h. UT transducer frequency, size and serial number.

i. UT couplant used.

j. UT calibration standard serial numbers.

k. If ultrasonic inspection is performed through paint, describe the paint condition and the specific technique used to compensate for paint.

l. Report the specific location and length of each discontinuity on the receiver.

m. Record all observations from the visual exams.

551-C.11 TAGGING.

Receivers that successfully pass the above testing shall have tags adhered to them. The following informa-tion, as a minimum, shall be stamped on each tag:

Example of stamping:

a. Recertification Activity: NSWCCD-SSES

b. Type of Recertification: UT/MT Method

c. Recertification Date (month-year): 03-2002

d. Receiver Serial Number or ID: Serial# 12345 or # 1 Ship Service Air Receiver image3.jpeg image4.png image5.png image6.png image7.png image1.jpeg image2.png