0903_A_ INSPECT SEA VALVES AND SEA CHESTS REV A.docx

USNS SPEARHEAD

(JHSV 1)

INSPECT SEA VALVES & SEA CHESTS REV A

1.0 ABSTRACT:

1.1 This item describes the requirement to inspect, overhaul, and test sea valves and sea chests.

2.0 REFERENCES/ENCLOSURE:

2.1 References

2.1.1 MSC Standard Item No. 21, “Sea Valves & Overboard Discharge Overhaul”

2.1.2 NAVSEA Drawing No. 8443037, “Arrangement – Sea Intakes”

2.1.3 NAVSEA Drawing No. 8443038, “Details – Sea Intakes”

2.1.4 NAVSEA Drawing No. 8443386, “Corrosion Prevention and Control Plan”

2.1.5 Stbd Main Engine Room AFT Sea Chest PPT.

2.2 Enclosure

2.2.1 Sea Valves list

3.0 ITEM LOCATION/QUANTITY/DESCRIPTION:

3.1 Locations of six (6) Sea Chests

3.1.1 Engine Room 1 & 2, Fwd/Aft, 12” Sea chest (Total 4)

3.1.2 Pump Room 5 & 6, Port/Stbd, 10” Sea chest (Total 2)

4.0 GOVERNMENT FURNISHED EQUIPMENT:

4.1 Replacement Sea Chest Sea Valves as needed.

5.0 NOTES:

5.1 The contractor and all subcontractors, regardless of tier, must consult the General Technical Requirements to determine applicability to this Work Item. In performance of this Work Item, the contractor and all subcontractors, regardless of tier, must comply with the requirements of all applicable GTR's.

5.2 The contractor and all subcontractors, regardless of tier, are advised to review other Work Items under this contract to determine their effect on the work required under this Work Item. Many of the definitions relating to performance of this Work Item are found in Work Item 001.

6.0 QUALITY ASSURANCE REQUIREMENTS: None additional.

7.0 STATEMENT OF WORK REQUIRED:

7.1 Remove all sea valves listed in Enclosure 2.2.1.

7.1.1 Prior to removal of sea valves conduct an operational test of all (12 total) Pneumatic Actuator Valves with the assistance of Ship’s Force to insure that each operator is operating correctly and document the operation.

7.1.2 Prior to removal and after assembly provide a continuity test from flange to flange across valve. Reading shall be recorded in OHMS. Readings shall be taken with vessel out of water.

7.1.3 Contractor will insure that the Pneumatic Actuator Valves is correctly aligned/timed prior to removal and is correctly aligned/ timed upon re-installation. Any discrepancies shall be noted and verified with CHENG. in regard to incorrect open or close indication. Only open or close indication shall be acceptable at the end of valve cycle completion.

7.1.4 All Sea Valves shall be tagged with a metallic stamped tag for location, removed from vessel, and set up in contractor’s facility for cleaning and inspection.

7.1.5 Perform Valve overhaul IAW Ref 2.1.1.

7.1.6 Inspect limit switches, and rotating parts. Insure all electrical connections are tight. Inspect for any water/moisture intrusion.

7.1.7 Issue as found report and as released condition to MSC Port Engineer.

7.1.8 Hydrostatically test all Valves to 100 PSI for five minutes and prove tight in the presence of the MSCREP and ABS Surveyor. Vessel owner may substitute GFE replacement valves in lieu of testing an original valve removed from vessel. Replacement valves shall have same salient characteristics.

7.1.9 Upon completion of all valve repairs and testing, re-install Pneumatic Actuator Valves in their original locations with contractor furnished garlock gaskets. Vessel owner may substitute GFE replacement valves in lieu of installation of an original valve removed from vessel. Replacement valves shall have same salient characteristics.

7.1.10 Operate the valves in the presence of the CHENG to insure proper alignment and operation. Guidelines of 7.1.2 shall be followed.

7.2 Open for inspection and cleaning 5 Main Sea Chests using Ref 2.1.3. DO NOT REMOVE FROM VESSEL. Remove Sea skin valves only.

7.3 Remove one (1EA) Sea Chest from vessel. Stbd No.1 Main Engine Room Aft Sea Chest shall be removed from vessel.

7.3.1 Reference 2.1.5 for repairs. Remove coating as needed to perform full replacement of 20MM Basket Retaining Ring. Reference DWGS 2.0.

7.3.2 All coating shall be removed and prepared for recoating.

7.3.3 Full interior including all valve and cover flanges shall be coated with two coats EA 2 MIL Nova Plate per manufacturer’s specifications.

7.4 All (6) Sea Strainer interiors shall be cleaned, prepped and painted with contractor furnished international intersleek coating. Coating shall be applied under the direction of international coatings rep provided in WI 905.

7.4.1 Flanges of removed strainer valve flanges shall be coated with Novaplate on both strainer and hull sides. Intall valves with garlock gaskets.

7.5 Issue as found report and as released condition to MSC Port Engineer.

7.6 Replace all disturbed O-rings and gaskets with new. Flange gaskets shall be 3/16” garlock. O-rings shall be as original O.E.M. material.

7.7 Contractor shall furnish and install new replacement zinc anodes in each unit. (see Ref 2.4, Appendix I for replacement specifications).

7.8 Sea chest shall be hydro pressure tested upon assembly, in place, to 15 psi in the presence of MSCREP and ABS Surveyor.

7.9 All damaged hardware shall be renewed.

7.10 For valve flange hardware, Nylon isolation bushings or isolation sleeves shall be used for all Steel and/or Stainless steel hardware. If isolation sleeves cannot be used, hardware shall be coated with Tef-Gel Isolation Compound as per Ref 2.1.4 Section 6.2.

8.0 GENERAL REQUIREMENTS: None

Enclosure 2.2.1 Sea Valves List

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