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1 and done. > Patches/Plugs/Seals > Flashcards

Patches/Plugs/Seals Flashcards

1
Q

Wrapping type seals must provide an acceptable leak rate for a minimum of _____ to confirm integrity prior to disassembly of internal seal.

A

30min

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2
Q

Can dewatering equipment be run continuously to establish an acceptable leak rate?

A

Yes. The personnel performing the internal repair SHALL be informed in writing that continuous educator operation is required to maintain acceptable leak rate.

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3
Q

Divers shall not leave the dive side until ______ is established, repairs are completed, or ships CO/esignated rep is granted.

A

double-barrier protection

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4
Q

What is the first reference drawing used when selecting stern tube seal?

A

Shafting arrangement drawing.

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5
Q

Un-stiffined flat patches shall be minimum ____ series aluminum, ____ mild steel, or ____ marine grade plywood.

A

1/4” 5000 series aluminum.
1/4” mild steel.
1” marine grade plywood.

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6
Q

Uncompressed gasket sealing material thickness shall be ____ inches.

A

2 inches.

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7
Q

All cofferdam applications must have a ______.

A

basic rigging plan.

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8
Q

All patches must have installed _____ or engraved serial number which corresponds to supporting documentation.

A

data plate.

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9
Q

Supporting documentation for a patch must include what 6 things?

A 
Patch rated depth.
Max hull opening size.
fabrication drawing.
Gasket requirements
educator and vent line requirements, and patch specific hull opening requirements.
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10
Q

All cofferdam to vessel hull seal gaskets shall be made of what material?

A

Closed cell foam material.

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11
Q

Closed cell foam material shall conform to ASTM D 1056-00 Type 2, Class B or C.
Grade 1 or 2 for application up to ____fsw.
Grade 2 shall be used for depths deeper than ____fsw.

A

35.

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12
Q

In no case shall gasket width be less than ____.

A

3 inches.

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13
Q

Grade 1 gasket material has a ___ psi compression deflection.

A

2-5 psi

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14
Q

Grade 2 gasket material has a _____ compression deflection.

A

5-9 psi

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15
Q

Where hydrostatic force is the primary compression load; Gasket area shall be suitably apportioned to limit the allowable gasket compressive stress to ____psi.

A

50psi

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16
Q

Where rigging force is the primary compression load; Gasket area should be designed to provide a minimum compression of ____psi for gasket sealing.

A

3.5psi

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17
Q

Gaskets shall not be designed for _____ to be applied.

A

Shear loading.

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18
Q

Fasteners shall be either _____ or ____ ____.

A

Steel or Stainless steel.

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19
Q

All patches shall be sealed to the hull opening by a gasket compressed under _______.

A

Differential Pressure

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20
Q

For seachests and piping systems with no means of internal venting, the patch shall be visually inspected for what? How often?

A

The patch shall be inspected or reduced gasket compression. On an interval not to exceed 7 days.

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21
Q

Can you use a Brass Handle on mechanical expandable plugs?

A

Yes.

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22
Q

Plugs must be _____ ____ or equal.

A

Standard stock.

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23
Q

For a Seachest with no internal venting: Inspect how often? Or install?

A

Minimum 7 days, or install a 1 psi gauge resolution.

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24
Q

O-ring diameter stretch, during installation, should not exceed?

A

5%

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25
Q

What can be used to seal a DC Plug to the hull?

A

Sealing Compound (Bintsuke.)

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26
Q

For mechanical expandable plugs, the _____ rather than differential pressure secures the plug and forms the seal.

A

Expansion of the plug.

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27
Q

What appendix is the patch and plug installation sheet?

A

Appendix D.

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28
Q

In a patch, internal release of pressurized air when opening the valve indicates what?

A

Entry of water past the cofferdam seal, causing remaining air bubbles to compress.

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29
Q

Are tapered mechanical plugs authorized?

A

No, they tend to dislodge during the tightening process.

30
Q

How do you remove a DC Plug?

A

Strike the sides with a hammer, or use a chisel.

31
Q

Can you use a cheater bar to tighten a mechanical plug?

A

No

32
Q

Are mechanical plugs with aluminum components authorized?

A

NO

33
Q

When are divers authorized to leave the dive station?

A

When double valve protection is established, repairs are completed, or permission is granted by the CO or his/her designation representative.

34
Q

Who signs the formal work package?

A

Repair activity & CO or designated representative.

35
Q

What is I.D. on a mechanical expandable plug?

A

Inner Diameter.

36
Q

Where can criteria for anode installation on ships and small boats operation in fresh water be requested from?

A

NAVSEA

37
Q

What qualifies as “Double-barrier protection” when no diver installed plug is present?

A

Installation of an internal sealing blank and a closed sea-chest valve.

38
Q

Patch and plug installation and inspection checksheets must be approved by whom?

A

CO (or designated representative) and the Repair Activity.

39
Q

Prior to installation of a plug, the ship’s CO shall be notified of what?

A

Location of the plug and whether it’s a single or double valve protection.

40
Q

Patch and plug checksheet shall remain where while the device is installed?

A

On file at the installing activity.

41
Q

For mechanical plugs, what is the requirement for the top plate or washer?

A

Must be larger than the opening being sealed.

42
Q

What is stamped on the end plate of each mechanical plug?

A

Size range. Can also be placed on a waterproof tag attached to the plug.

43
Q

The plug must have a seated pressure rating at least how much ___ times the static pressure head it will seal?

A

1 ½ times.

44
Q

If a Seachest has no means of internal venting, the patch shall be visually inspected by divers for what?

A

Gasket decompression.

45
Q

An isolation valve for an internal vent shall be opened during inspection and observed for what?

A

The presence of water or rushing air.

46
Q

After removing a plug, divers should remain for how long?

A

Until they receive word that no leaks exist.

47
Q

When installing a plug, what needs to be cleaned?

A

Clean the hull surface and opening of any fouling, cleaning as far into the opening as the plug will reach.

48
Q

For a DC wooden plug that is longer than ____ inches, it may need to be trimmed down so that a max of ____ to ____ inches protrudes from the opening.

A

8 Inches

3-4 inches

49
Q

Where can information be found on a hull’s appendage (i.e. exact location and arrangement.)?

A

Docking plan

50
Q

Patch and Plug INSPECTION checklist is what appendix?

A

Appendix C

51
Q

What is the shim spacing on an unstiffened flat patch?

A

Max 5 inch shim spacing.

52
Q

True/False A Zero Leak rate seal shall be confirmed at the internal repair area prior to removing piping fasteners?

A

TRUE

53
Q

A patch rigging plan includes what?

A

Lifting requirements, securing and attachment requirements, manufacturer, and weight test requirements.

54
Q

Uncompressed gasket sealing material thickness shall be what?

A

2 inches

55
Q

All patch pipe nipples used to attach the suction side of dewatering eductors must have what installed to secure the space when dewatering is complete?

A

A valve.

56
Q

Why are excessively long plugs not recommended?

A

They are harder to install, and pose a great risk to becoming fouled and dislodged.

57
Q

During single-valve isolation, what must be rigged and operationally ready prior to commencing work?

A

Dewatering equipment, and an emergency plan must be in place to act the entire time single-valve protection is established.

58
Q

Whenever single valve protection is in place, the repair activity shall include what?

A

A written notification, and a specific plan for immediate installation of a replacement piping component or internal sealing blank.

59
Q

What if you are unable to achieve a “0 Leak Rate”?

A

A leak rate with dewatering equipment secured that is acceptable to personnel performing internal repair work must be established, as well as the ship’s DC equipment must be on hand.

60
Q

When hull configuration limits the force applied by the hogging lines, the use of a _______ should be considered to provide the sealing force required.

A

Stand-off

61
Q

What is the rubber in a mechanical expandable plug made of?

A

30 Durometer

62
Q

Can an isolation valve for an internal vent be left continuously open?

A

Yes, if approved by the ship an internal vent may be left open to maintain cofferdam differential pressure.

63
Q

What is the minimum PPE while making Binstsuke?

A

Glasses, heat gloves, faceshield, coveralls, leather apron, steel toed boots, and an ABC fire extinguisher. ←Look this up

64
Q

How do you bleed off pressure to ensure a patch or plug has positive seal?

A

Open an installed bleed valve, or slowly loosen an internal flange. Only loosen, don’t remove.

65
Q

If an internal blank has been installed, the integrity of the diver installed plug must be _________ prior to removing the blank. Plug seal integrity should never be assumed.

A

re-established/re-verified

66
Q

If no other internal vent exists, the internal sealing blank shall have a _____ installed.

A

Less than 1/2 in diameter vent valve installed.

67
Q

Supporting patch documentation must include what?

A

Patch rated depth, max hull opening size, fabrication drawing, gasket requirements, eductor and vent line requirements, and patch specific hull opening attachment and alignment requirements.

68
Q

All patches shall be vented to atmospheric pressure by using what?.

A

An internal seachest vent, or an external non collapsible vent line.

69
Q

A _______ MUST be installed and opened prior to operation of a dewatering eductor.

A

vent line.

70
Q

When securing a patch to the hull, a temporary device such as a spider may be used to aid initial seating but ________ must also be used.

A

An additional means of securing, such as a hogging line.

71
Q

If a __________temporary securing device is used as a positive attachment, a hogging line is NOT required.

A

a NAVSEA approved {temporary securing device}

1 and done. (22 decks)

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