J15--Submarine_Maintenance_Standard_6350-081-001 _Inspect _Repair_Vibration_Damping.pdf

FOR OFFICIAL USE ONLY

SUBMEPP

MS NO. 6350-081-001 REV F CHG-3

SUBMARINE

MAINTENANCE

STANDARD

MR DESCRIPTION: Inspect; repair vibration damping.

SUBMEPP APPROVAL

Martha M. Bowman

SYSTEM/COMPONENT ENGINEER/TECHNICIAN

Jim Rizas 3/16/10

DESTRUCTION NOTICE. Destroy by any method that will prevent disclosure of contents or reconstruction of the document.

DISTRIBUTION STATEMENT D. Distribution authorized to DOD and DOD contractors only (Administrative/Operational use). Other requests shall be referred to COMNAVSEASYSCOM or higher DOD authority.

PROGRAM MANAGER DATE

Class: SSBN726

REVISIONS/CHANGES

REV DESCRIPTION SUBMEPP

APPROVAL & DATE

B The MRP was changed to:

1. Incorporate Cover Page and History Page i.

2. Incorporate PARM input to delete DRF attachment and associated note.

3. Renumber subsequent attachment, quoted attachment, and notes.

4. Delete SMIC column from MRPL.

Eric E. Blough 1/6/92

C The MS was revised to:

1. Incorporate SUBMEPP comments (updated format).

Gary Jewell Eric E. Blough

3/20/98

D The MS was revised to:

1. Incorporate SUBMEPP comments (clarified inspection criteria and deleted inspection for special treatments. Inspection will be covered in MS No. 4690-081-002).

2. Incorporate UACS SUBMEPP-00-006 (added criteria for plastic restraining covers).

Howard M. Walters Eric E. Blough

7/21/00

D

CHG-1

CHG-1 consists of Cover Page, Page i, and Page 4 of 6. The MS was changed to:

1. Incorporate UACS PSNS-00-048 (changed text requirement to reference MIL-STD-2148 (SH), for replacement of tiles for affected area greater than 10 percent of damped area).

Howard M. Walters Scott E. Mercer

2/16/01

D

CHG-2

CHG-2 consists of Cover Page, Page i, and Pages 1, 3, and 4 of 6. The MS was changed to:

1. Incorporate SUBMEPP comments (added CRES for fastener system inspection).

Howard M. Walters Scott E. Mercer

12/21/01

MS NO. 6350-081-001 REV F PAGE i

REVISIONS/CHANGES

REV DESCRIPTION SUBMEPP

APPROVAL & DATE

E The MS was revised to:

1. Incorporate SUBMEPP comments (added depth control tank and fwd trim tank damping criteria).

Howard M. Walters Scott E. Mercer

7/18/03

F The MS was revised to:

1. Incorporate SUBMEPP comments (incorporated/clarified structural criteria for steel under tiles and updated SUBMEPP’s address on the MCF Requirements form).

Martha M. Bowman Scott E. Mercer

8/20/04

F

CHG-1

CHG-1 consists of Cover Page, Page ii, Page 1 of 9, and Attachment 3, Pages 4, 6, and 8 of 8. The MS was changed to:

1. Incorporate SUBMEPP comments (updated Reference (b) and updated GAC attachment to Revision H CHG-1 requirements).

Martha M. Bowman Scott E. Mercer

2/17/06

F

CHG-2

CHG-2 consists of Cover Page, Page ii, Pages 1 and 4 through 6 of 9, and Attachments 1 and 3, Pages 1, 2, and 4 through 6 of 8. The MS was changed to:

1. Incorporate UACS SUBMEP-08-116 (changed Attachment 1 to a new, damping tile specific MCF form).

2. Incorporate SUBMEPP comments (updated GAC attachment to Revision H CHG-2 requirements).

Martha M. Bowman Scott E. Mercer

7/15/08

F

CHG-3

CHG-3 consists of Cover Page, Page ii, Pages 1 and 4 through 6 of 9, and Attachment 3, Pages 4 through 6 and 8 of 8. The MS was changed to:

1. Incorporate UACS SUBMEP-09-283 (updated MS to reflect DDGOS Rev A, ACN M05-09, allowing the use of VHB tape on selected tile).

2. Incorporate SUBMEPP comments (deleted CRES warning;

included CRES information in Step 1.c.(6); added optional use of ULTEM per DDGOS change; and updated GAC attachment to Revision H CHG-3 requirements).

Martha M. Bowman Jim Rizas 3/16/10

MS NO. 6350-081-001 REV F CHG-3 PAGE ii

MAINTENANCE STANDARD

EQUIPMENT/COMPONENT

Vibration Damping

MS NO. 6350-081-001

SYSTEM

Hull Insulation

RELATED MAINTENANCE

URO MRC 003

MS No. 4690-081-002 MS No. 6310-081-015

MR DESCRIPTION

1. Inspect; repair vibration damping.

ATTACHMENTS

1. Damping Tile Material Condition Report

2. Equipment Guide List/Maintenance Requirement Parts List

3. Applicable Steps of General Acceptance Criteria (GAC)

TECHNICAL REFERENCE DATA

(a) Conduct Hull Structural Survey URO MRC 003

(b) Submarine Structural Inspection and Repairs MS No. 7650-081-091

(c) Submarine Preservation MS No. 6310-081-015

(d) Welding and Allied Processes, NSTM Chapter 074 NAVSEA S9086-CH-STM-010/CH-074

(e) SSBN OHIO Class Submarine Alteration Design Document

MSL Tube Superstructure Damping Tile NAVSEA Drawing F100061 TRID: 249

(f) Vibration Damping Materials, Procedures for Installation, Maintenance and Repair

MIL-STD-2148 (SH)

SAFETY PRECAUTIONS

1. Observe standard safety precautions.

2. RadCon survey must be completed prior to inspecting areas in or adjacent to the reactor compartment and external areas of the ship’s pressure hull.

3. Tanks and void spaces must be certified gas-free prior to entry and periodically to ensure safe, gas-free working conditions.

4. Avoid prolonged contact with, or inhalation of, cleaning solvents. Avoid use near heat or open flame and provide adequate ventilation.

5. Trichloroethane cleaning solvent must not be used. Replacement material must be PF-145HP degreaser.

MS NO. 6350-081-001 REV F CHG-3 PAGE 1 OF 9 |

BOUNDARIES

1. Boundaries of this MS are vibration damping including all damping material and fasteners interior and exterior to the ship’s pressure hull.

MS NO. 6350-081-001 REV F PAGE 2 OF 9 |

Figure 1. Typical Vibration Damping Installation

MS NO. 6350-081-001 REV F PAGE 3 OF 9 |

PROCEDURE

Preliminary

NOTE 1: In instances where design criteria (e.g., surface finishes, tolerances, etc.) conflict with the criteria of this MS, the criteria of this MS must govern.

a. Ensure compliance with Type Commander’s instructions before entering tanks.

b. Ensure compliance with Type Commander’s instructions when working in the sail.

WARNING: RadCon survey must be completed prior to inspecting areas in or adjacent to the reactor compartment and external areas of the ship’s pressure hull.

WARNING: Tanks and void spaces must be certified gas-free prior to entry and periodically to ensure safe, gas-free working conditions.

c. Ensure fairwater planes, stern planes, and rudder are tagged out in accordance with Type Commander’s instructions.

1. Inspect; repair vibration damping.

NOTE 2: All exterior vibration damping installed is identified in Table 1. All interior tank vibration damping installed is identified in Table 2.

1.a. Compare the damping coverage areas with the actual installation drawings as listed in Table 1 and Table 2 and correct deficiencies. Report missing tiles by area in Attachment 1 Column K.

1.b. Corrosion:

NOTE 3: The tile inspector must be aware of the Reference (a), Reference (b), and Reference (c) interactions with the technical requirements of this MS.

1.b.(1) Inspect the underlying structure in way of missing or removed tiles and the steel between and around the tiles in accordance with Reference (a) or Reference (b), as applicable. This is to determine if additional tiles need to be removed for further evaluation of the underlying structure.

For tiles not removed but rust bleeding coming from under the tile or fastener is present, a structural inspector must determine that the material condition under the tiles is adequate in accordance with Reference (a) or Reference (b), as applicable. This inspection must be coordinated with the Reference (a) inspection when it is authorized.

1.b.(2) If excessive rust bleeding, corrosion products, deformed and/or lifting tiles are found, the tiles must be removed to determine the material condition of the underlying structure in accordance with Reference (a) or Reference (b), as applicable. Excessive rust bleeding is defined as rust bleeding from a fastener or from behind a tile. Rust staining by itself is not considered excessive, but debonded tile or evidence of paint failure under the tile is reason for tile removal. Report tiles removed for debonding or evidence of paint failure or corrosion under the tile in Attachment 1 Column C, F, or I, as applicable.

MS NO. 6350-081-001 REV F CHG-3 PAGE 4 OF 9 |

PROCEDURE (Cont’d)

1.b.(3) Repair structural defects in accordance with Reference (a), Reference (b), and Reference (d), as applicable.

1.b.(4) Represervation, including coating evaluations, must be in accordance with Reference (c).

1.b.(5) Visually inspect the restraining/constraining studs, nuts, and washers for evidence of corrosion (rust) or deterioration. If there is evidence of corrosion or deterioration, correct deficiencies.

1.c. Visually inspect damping in accordance with Step 1.c.(1) through Step 1.c.(8) and correct deficiencies.

NOTE 4: Prior to disassembly, refer to Instructions for Material Condition Feedback (MCF) Requirements in Attachment 1.

NOTE 5: For SSBNs 726 and 727, inspection resulting in repair/replacement to lower 2 rows of damping material between missile tube superstructure frames 52 and 83, port and starboard, must be in accordance with Reference (e).

NOTE 6: Missing damping can be identified by fouled surfaces (e.g., leftover adhesive, evidence of missing or broken studs, tiles, etc.). Clean surfaces show that sound damping was not installed (e.g., around zincs, in way of shore connection hatches, loading hatches, etc.); these areas are also identified in Table 1.

1.c.(1) Loose, cracked, broken, or missing constraining/restraining layers are not acceptable.

NOTE 7: Nut removal solely to determine acceptability of threads is not required.

1.c.(1)(a) Maximum allowable reduction in constraining layer thickness due to corrosion or pitting is 0.020” or 20 percent of original design thickness, whichever is less.

1.c.(1)(b) Areas of plastic restraining covers that have minor damage such as a roughened surface (for example, by abrasive blasting), does not need to be repaired unless the effectiveness of the cover is impaired.

1.c.(2) When damping tiles or the restraining covers exposed to seawater or in wet spaces are removed for any reason, all parts of the fastener system (stud, nut, and washers) must be checked to ensure that all material is CRES and replaced if not CRES. Any part of the fastener system (stud, nut, or washer) must be replaced if it is not CRES. Do not mix carbon steel and CRES fastener pieces.

1.c.(3) Utilizing a rubber mallet, lightly strike the washer to ascertain tightness of the nut and correct deficiencies (see Figure 1).

1.c.(4) Loose, cracked, broken, or missing nuts or washers are not acceptable. Threads must meet the requirements of Attachment 3 Step 1.e.(2).

1.c.(5) Broken or missing studs are not acceptable. Threads must meet the requirements of Attachment 3 Step 1.e.(2). Replace broken or missing studs in accordance with Reference (f) and Step 1.c.(6).

Report tiles removed for unsatisfactory studs in Attachment 1 Column B, E, or H, as appropriate.

NOTE 8: CRES fasteners may be used in dry spaces if desired.

MS NO. 6350-081-001 REV F CHG-3 PAGE 5 OF 9 |

1.c.(6) Material for replacement studs, nuts, and washers for damping tiles exposed to seawater or in wet spaces must be the right material. If any part of the fastening system is replaced, all fastener parts must be checked to ensure the installed material is correct. Do not mix carbon steel and CRES fastener pieces.

1.c.(6)(a) Studs must be type 316L (UNS No. S31603) in accordance with MIL-S-24149.

1.c.(6)(b) Material for replacement nut and washers may be fiberglass reinforced ULTEM 2300 plastic flanged nuts per EBDIV Specification 3722. When CRES is used, 316L should be used because of its superior corrosion properties; however, for nuts and washers only, if 316L is not available, 316 may be used.

1.c.(6)(b)1 CRES nuts must be hexagonal for 250 degree service in accordance with NASM 25027.

1.c.(6)(b)2 CRES washers must perform in accordance with ANSI-B-27.2.

1.c.(6)(c) Prior to assembly of CRES nuts and studs and CRES washer/nut assemblies and studs, the stud threads must be coated with an anti-seize compound in accordance with MIL-T-22361.

1.c.(7) Evidence of damage or destruction due to heat from welding or burning is not acceptable. Report tiles removed for unsatisfactory condition in Attachment 1 Column D, G, or J, as appropriate.

1.c.(8) Gaps between nut and/or washer and damping tile or constraining/restraining layer are not acceptable.

WARNING: Avoid prolonged contact with, or inhalation of, cleaning solvents. Avoid use near heat or open flame and provide adequate ventilation.

WARNING: Trichloroethane cleaning solvent must not be used. Replacement material must be PF-145HP degreaser.

1.d. If tiles are missing, loose, deformed, or damaged and account for 10 percent or less of the damped area, the affected tiles must be removed and the surface represerved to meet the requirements of Reference (c). Installation of new tiles is not necessary.

1.e. If tiles are missing, loose, deformed, or damaged and account for greater than 10 percent of the damped area, the missing, loose, or damaged damping material must be replaced in accordance with Reference (f), except as noted in Step 1.f. of this MS. Preservation must be in accordance with Reference (c).

1.f. For Type II, Class 1 (color coded blue), Type V Class 2 (color coded orange), and Type II, Class 2 (color coded white - with no steel constraining sheets) tiles only, tiles may be installed with 3M Corporation Very High Bond (VHB) tape number 4926. Tiles installed using VHB tape must be installed in accordance with Reference (a) as amended by UIPI 9802-105.

1.g. Submit Attachment 1 under cover letter to NAVSEA 05U7T and SUBMEPP Code 1844 upon completion of this MS.

MS NO. 6350-081-001 REV F CHG-3 PAGE 6 OF 9 |

Area Inspection Points

Longitudinal Support Frames 4-10

Bow Structure Frames 4-10 Flat

Bow Free Flood

Access Trunk to GRP Dome

MBT 1A and 1B Bulkhead Frames 4, 5, and 6

Non-Pressure Hull Frames 7, 8, and 9

Non-Pressure Hull Plating Frames 6-27

Torpedo Tube Recess NOTE: Areas in way of BQN-3 enclosure and low frequency sonar array are not damped.

Main Ballast Tank Bulkhead 10 and Non-Pressure Hull Frame 11

Main Ballast Tank Bulkhead 15 and Non-Pressure Hull Frame 16

Non-Pressure Hull Frames 12, 13, and 14 Frames 17, 18, and 19 Frames 20, 21, and 22

MBT 1A and 1B MBT 2A and 2B MBT 3A and 3B

Center Line Longitudinal Bulkhead Frames 4-15 Frames 15-25

Sonar Sphere Support Structure Structure Support Frames 1-4

Fairwater/Sail Plating Frames 33-43 NOTE: Areas in way of voids, high frequency projectors, acoustic window, and side lights are not damped.

Fairwater Frames

Fairwater/Sail

Fairwater Flats

Non-Pressure Hull Frames 141, 142, and 143 Frames 144, 145, and 146 Frames 149, 150, and 151

Frames 152, 153, 154, and 155 Frames 158, 159, and 160

Frames 163, 164, 165, and 166 Frames 167-172

MBT 4A and 4B MBT 5A and 5B

MBT 6 and Aft Free Flood

Non-Pressure Hull Frame 147 and Bulkhead Frame 148

Table 1. Exterior Vibration Damping Inspections

MS NO. 6350-081-001 REV F PAGE 7 OF 9 |

Table 1. Exterior Vibration Damping Inspections (Cont’d)

Area Inspection Points

MBT Bulkhead 156 and Frame 157

MBT Bulkhead Frames 161, 162, and 162A

Non-Pressure Hull Plating Frames 135-156 Frames 157-172

Pressure Hull Frames 138 and 139 Frames 140 and 141

MBT Baffles

Centerline MBTs Bulkhead Frames 137-156

Longitudinal Bulkhead and Stringers Frames 156-172

Anchor Bolster Hawser and Chain Pipe

Stabilizer Structure

Shaft Tube Bearing Support

MBT 4A and 4B MBT 5A and 5B

MBT 6 and Aft Free Flood (Cont’d)

Secondary Propulsion Motor Recess Structure

Missile Hatches Superstructure Main Deck

Frames 25-125 NOTE: Areas in way of DSRV seats, shore connection hatches, countermeasures loading hatches, safety line track, missile loading pads, communication buoy hatches, thru penetrations, hinged deck cleats, and AN/BST-1 are not damped.

Superstructure Frames Frames 26-31, Frames 33-51 *Frames 53-61, *Frames 63-70

*Frames 72-79, *Frames 81 and 82 Frames 84-93, Frames 95-104

Frames 106-112, Frames 114-117 Frames 119-125

Superstructure

Swash Bulkheads Frames 23, 52*, 62*, 71*, 80*, 83*, 94, 105, 113, and 118

* For SSBNs 726 and 727, inspection resulting in repair/replacement to lower 2 rows of damping material between missile tube superstructure frames 52 and 83, port and starboard, must be in accordance with Reference (e).

MS NO. 6350-081-001 REV F PAGE 8 OF 9 |

Area Inspection Details

Depth Control Tanks Sound Damping FR 82D through FR 94 Sections NAVSEA dwg 607-4674658

Fwd Trim Tanks Sound Damping FR 18 through FR 49 Sections NAVSEA dwg 607-4674656

Table 2. Interior Tank Vibration Damping Inspections

MS NO. 6350-081-001 REV F PAGE 9 OF 9 |

Attachment 1

Damping Tile Material Condition Report

Instructions

(1) Complete the form with information from the specific hull and availability being worked.

(2) Include number of all tiles removed during an availability, including tiles damaged during blasting and preservation work in a tank.

(3) Report only MBT data.

(4) The same information is being gathered for 3 different categories of installation methods: 1) Damping Tile with Steel Restraining Layer, 2) Damping Tile with Non-Steel Restraining Layer, and 3) Damping Tile with no Restraining Layer.

(5) For each category, indicate how many tiles will be removed for each failure type.

If a tile qualifies for replacement for more than 1 failure type, it should be counted for each applicable failure type (up to 3 times).

(6) Columns B, E, and H reflect tile removal due to stud, nut, washer, and/or nut/washer assembly failure.

(7) Columns C, F, and I reflect tile removal due to substrate (structure under the tile) corrosion or preservation system failure.

(8) Columns D, G, and J reflect tile removal due to damping tile and/or restraining/constraining layer failure. This column is divided into 2 sub-columns to allow activities to differentiate between tiles damaged in service (“As Found”) and tiles damaged due to maintenance work in the tank (“Maint”) such as blasting.

(9) Column K reflects the number of tiles noted as missing when the tank was opened.

(10) The comments block is for any pertinent information in regard to the damping system in the tank. It could include localized failure that can be attributed to a single cause, large numbers of failures due to surface prep or other tank work, comments on the straining system, etc.

MS NO. 6350-081-001 REV F CHG-2 PAGE 1 OF 8 |

FO

R O

FFIC

IA

L U

SE

O N

LY

A ttachm ent

Hull #: Avail Date: Avail Type:

Damping Tile w/Steel Restraining/Constraining Layer

Damping Tile w/Non-Steel Restraining/Constraining Layer

Damping Tile w/no Restraining/Constraining Layer

B C D E F G H I J K

A # Tiles remvd for Unsat/ Missing Stud(s)

# Tiles remvd for tile damage

# Tiles remvd for Unsat/ Missing Stud(s)

# Tiles remvd for tile damage

# Tiles remvd for Unsat/ Missing Stud(s)

# Tiles remvd for tile damage

# Tiles missing when tank opened

Tank CRES Steel

# Tiles remvd for delamination or corrosion of substrate As

Found Maint CRES Steel

# Tiles remvd for delamination or corrosion of substrate As

Found Maint CRES Steel

# Tiles remvd for delamination or corrosion of substrate As

Found Maint

MBT 1A

MBT 1B

MBT 2A

MBT 2B

MBT 3A

MBT 3B

MBT 4A

MBT 4B

MBT 5A

MBT 5B

MBT 6

Comments:FO R O

FFIC

IA

L U

SE

O N

LY

M S N O 6350-081-001

R

EV

F C H G -2

PA

G E O F

Attachment 2

Equipment Guide List and Maintenance Requirement Parts List

EQUIPMENT GUIDE LIST

IDENTIFICATION NO. APL

Hull Insulation T89GEN6350

MAINTENANCE REQUIREMENT PARTS LIST

DRAWING NO. None

DESCRIPTION PIECE

NO. QTY CAGE PART NO. *M/C/S

None

* Mandatory/Contingency/Special Tool

MS NO. 6350-081-001 REV F PAGE 3 OF 8 |

Attachment 3

Applicable Steps of General Acceptance Criteria (GAC)

NOTE: This attachment contains only those steps from MS No. 7650-081-001H CHG-3, General Acceptance Criteria, that are necessary to accomplish the inspections required by this MS. A list of definitions is located at the end of this attachment.

1. General acceptance criteria

TECHNICAL REFERENCE DATA

(a) Submarine Fastening Criteria NAVSEA S9505-AM-GYD-010

1.e. Threaded fasteners (including self-locking fasteners and locking elements), Acme threads, and tapped (bolt) holes:

NOTE 25: Except for threads covered by pressure and non-pressure hull tapped hole inspections, removal of threaded fasteners or thread inserts only to determine acceptability of threads is not required.

NOTE 26: Reinstallation of studs with anaerobic sealant must be in accordance with recommended vendor procedures or approved local overhaul facility procedures.

NOTE 27: If necessary, threads should be cleaned before applying these acceptance criteria.

NOTE 28: Thread requirements apply to the load bearing portions of the fastener only. Defects are acceptable on the free end of the fastener only if they cannot cause damage to the engaging threads.

NOTE 29: Except for low-alloy and carbon steels above 1000°F or other fastener materials above 670°F, continued use of silver plated fasteners when the silver plating is worn is acceptable, provided that anti-galling (compound) lubricant per CID A-A-59004 (Molykote P-37 paste), is applied to the threads.

NOTE 30: Steam turbine fasteners with original copper plating disturbed need not be replated or replaced, provided anti-galling (compound) lubricant per CID A-A-59004 (Molykote P-37 paste) is used.

Except for low-alloy and carbon steels above 1000°F or other fastener materials above 670°F, if replacement fasteners are necessary, they need not be copper plated, provided anti-galling (compound) lubricant per CID A-A-59004 (Molykote P-37 paste) is used.

NOTE 31: Reference (a) should be used for repair, installation, and replacement of threads and fasteners.

MS NO. 6350-081-001 REV F CHG-3 PAGE 4 OF 8 |

NOTE 32: “Type I” and “Type II” inspections as found in the GAC, serve only to identify different levels of inspection. “Definitions” of Type I and Type II have not been provided to avoid defining or guiding the level of inspection required, and to avoid the potential misapplication of the GAC requirements. It is intended that engineering or technical individuals invoke Type I, Type II, or an alternate fastener inspection level, depending on the specific application. A Type I inspection is typically used for pressure containing and critical thread SUBSAFE applications, LEVEL 1 applications, and other pressure containing applications. Type I fastener criteria is also normally applied to fasteners for which a torque requirement is also specified in the associated maintenance standard. A Type II inspection is typically used for non-critical applications.

An engineering evaluation of the loads in the joint can result in exceptions to this general usage; for example, a Type II thread inspection is currently authorized for LEVEL 1 pressure containing pump cover fasteners in the SUBSAFE SSN688Cl Byron Jackson MSW pump.

NOTE 33: During an overhaul period, it is not necessary to replace the nylon locking pellets in male self-locking fasteners that were originally assembled with new locking pellets if the fastener is subsequently required to be disassembled to support shipboard installation/reassembly of the component or grooming/maintenance of the component.

1.e.(2) Type II threaded fasteners (including self-locking fasteners and locking elements) and tapped (bolt) holes:

1.e.(2)(a) Visible cracks are not acceptable.

1.e.(2)(b) Thread defects that do not go beyond the thread root diameter are acceptable provided total surface of all engaged threads is not reduced more than 10 percent as estimated visually.

1.e.(2)(c) Clearance fit threads must engage by hand.

1.e.(2)(d) The locking insert (plug, patch, or chemical patch type) on externally threaded male fasteners should be replaced at each reuse because it provides a relatively small locking area to begin with, and it normally does not meet acceptable locking torque after a few uses. (Renewal of these nylon elements can be accomplished locally.)

Locking elements on male fasteners may be reused if fastener breakaway torque is at least 25 percent of the values listed for the appropriate fastener size in Reference (a) Table 3-4.

In those cases where repair activities encounter insurmountable scheduling or logistics circumstances, and subsequently judge that the fastener must be reused without replacing the locking element, an anaerobic thread locking compound (such as ASTM D5363, AN0141 or AN0143) may be applied to allow future removal with just hand tools. (Example of “scheduling or logistics” problems: unscheduled repairs of components with installed male fasteners, lack of nylon stock, insufficient time to send patch fasteners to a qualified vendor, broken machine tools that are used to manufacture the insert, and so on.) Loctite should not be used with any thread lube/anti-galling compound. For SUBSAFE, LEVEL 1, pressure-containing, underwater explosion (undex) qualified applications, or where the drawing records a torque value, engineering should recalculate an acceptable torque using an estimated Loctite coefficient of friction (cf). For non-critical applications, torque Loctited fasteners to “wrench tight”.

MS NO. 6350-081-001 REV F PAGE 5 OF 8 |

Self-locking nuts must meet the requirements of Reference (a) Paragraph 3-38.e(1).

1.e.(2)(e) Ineffective wrench flats, drive slots, or spanner wrench slots are not acceptable.

MS NO. 6350-081-001 REV F PAGE 6 OF 8 |

Definitions

Acme Threads - a frequent thread choice for power transmission, yielding more efficiency than the typical machine thread, commonly known as a “V” thread. Although more difficult to machine, the Acme thread’s basic screw geometry attributes to its lower losses, including friction, which in turn means less wear and ultimately longer life.

A “V” thread has an angle of 60 degrees between opposing faces, while the Acme is only 29 degrees.

Dynamic Radial Seal - an O-ring (or quad-ring) seal configuration where the parts being sealed are cylindrical, with one part contained within and concentric with the other, and subject to relative motion along the common cylinder axis. The direction of pressure is perpendicular to the plane containing the O-ring. Generally, the seal is constrained in the concentric space between the 2 sealed parts by means of a rectangular groove machined into the circumference of one of the mating sealing surfaces. Sealing is accomplished both by compression of the seal cross-section (squeeze) within the assembled gland and by some degree of pressure deformation of the seal into the gap between the sealed parts.

Dynamic Surface - Dynamic surfaces are surface areas (sealing and non-sealing) that have relative motion with another part excluding mating surfaces where the relative motion is a slow rotation of less than 1 turn. The relative motion may be but is not limited to rubbing, sliding, hard intermittent contact, etc., as occurs in (but not limited to) the following:

1) Valve stem “O” ring seal area or groove (more than 1 turn required for valve operation)

2) Valve stem bore “O” ring seal area or groove (more than 1 turn required for valve operation)

3) Lift/swing check valve disc/clapper seat area

4) Snorkel head valve seat area

5) Diesel/air induction hull/backup valve flapper seat area

6) Operating shaft “V” packing seal area

7) Valve disc/seat contact areas

Hull Flange - a flange that is directly fastened to the pressure hull, and should failure occur, would allow uncontrollable flooding into the submarine.

Major Repairs - are those repairs that can potentially affect the structural integrity of a pressure-containing portion of a piping system or component. Examples of these repairs include most welding (“minor” welding repairs are defined in NAVSEA S9074-AR-GIB-010/278), brazing or other fabrication processes, including new mechanical joints in which a flange or union tailpiece is replaced using a weld or braze, and the installation of new pressure boundary parts or components which have not been previously strength tested.

Minor Repairs - are repairs that do not qualify as “Major”. Examples include operations that could be considered maintenance such as replacing packing and pressure seal rings, lubricating, lapping or grinding seats, and replacing damaged parts such as stems and discs.

Non-hull Flange - A flange that is not a hull flange.

Static Face Seal - an O-ring seal where the O-ring groove is machined into the inner face of one of 2 mating flanges.

Pressure acts radially outward on the seal, tending to force the O-ring against the outer circumference of the groove.

Static Radial Seal - same configuration as that of a dynamic radial seal except that there is no relative motion between sealed parts.

MS NO. 6350-081-001 REV F PAGE 7 OF 8 |

Definitions (Cont’d)

Static Surface - Static surfaces are surface areas (sealing and non-sealing) that remain in stationary contact with their mating part/member.

Note: For repairs and inspections, mating surfaces having relative motion must be considered static surfaces if the relative motion is intermittent with low frequency of operation and of 1 cycle or less. For example, the valve stem seal areas on valves that are normally operated only to accomplish specific system line-ups and are fully opened or closed when the stem is rotated 90 degrees (1/4 turn) should be considered static. All other areas are considered to be dynamic surfaces. Refer to NAVSEA-approved procedures for current brush plating requirements on static sealing and non-sealing surfaces.

Straight Thread Tube Fitting Boss Seal - an O-ring seal configuration designed to seal threaded connections, such as plugs or threaded tubes. The O-ring gland is created by the inner face of the plug or tube “boss” (the face in way of the part into which the male piece is threaded) and the chamfer machined into the outer edge of the tapped hole. When the plug/tube is fully threaded into the mating hole, the O-ring is compressed into the semi-triangular shaped space thus formed, creating a seal. O-rings used in straight thread tube boss seals are often of higher durometer than those used in other applications.

Type I Fasteners - Type I fastener classification is determined by Engineering based on specific function and/or design. Generally included in this group are SUBSAFE fasteners, pressure boundary fasteners in Level I systems, and fasteners for which a torque requirement is specified in the associated maintenance standard.

Type II Fasteners - are determined by Engineering to not require Type I inspection criteria. Included in this group are those fasteners for which a torque requirement is not specified in the associated maintenance standard.

V-ring Packing Seals - a seal configuration where the parts being sealed are cylindrical, with one part contained within and concentric with the other. These parts are usually subject to relative motion along the common cylinder axis. The seal assembly is constrained by a machined groove in the outer sealing surface and held in place by an adapter flange. The seal assembly is made up of a male and female adapter between which are compressed several sealing rings that have a “vee” shaped cross-section. The direction of pressure is both perpendicular to the packing diameter and in a direction which tends to expand the “vee” packing rings against the sealing surface of the inner part. Consequently, sealing tends to be pressure activated.

MS NO. 6350-081-001 REV F PAGE 8 OF 8 |