USNS MARY SEARS
T-AGS 65
Solic. No.: MLL-16-T65-0002
MACHINERY, AUXILIARY SYSTEMS October 11, 2016
ITEM NO. 0501 Category “A” USMMI/MLL/RCS
Revision A
CLEAN VARIOUS HEAT EXCHANGERS
1.0Abstract
1.1Clean various system salt water coolers and associated piping. Inspect, blast and coat the end bells on #1 AC Plant and both refrigeration plant heat exchangers and the main diesel engine heat exchanger water channels with BelzonaSupermetalglide 1341.
2.0References/Enclosures
2.1NAVSEA T9514-BM-MMO-010; Chill Water Plant 84.6 Ton Capacity
2.2NAVSEA T9516-AX-MMO-010; Ship’s Stores Refrigeration Plant 2.2 Ton Capacity
2.3NAVSEA T-AGS60CL-033/2; Bow Thruster FS 500-234MNR, Vol 2
2.4NAVSEA Drawing 501-7400510;Piping Module 10
3.0Item location/description/quantity
3.1Locations: Various Machinery Spaces throughout the ship
3.2Description: Heat Exchangers
3.2.1 -Quantity (2) each – A/C condenser
3.2.2 -Quantity (2) each - Steering system heat exchangers
3.2.3 -Quantity (4) each - EMD jacket water coolers
3.2.4 -Quantity (1) each – Bow thruster lube oil cooler
3.2.5 - Quantity (2) each – Refrigeration condenser
3.2.6 – Quantity (2) each – Port & starboard gear oil coolers
3.2.6.1Port Propulsion Gear Oil Cooler:
MFR: Alfa Laval
Model: M6-MFG
S/N: 30113-87581
57.26 Square Feet
144mm wide x 40 each 0.50MM Plates
MAWP: 150 PSI @250F
3.2.6.2Starboard Propulsion Gear Oil Cooler:
MFR: Alfa Laval
Model: M6-MFG
S/N: 30113-87580
57.26 Square Feet
144mm wide x 40 each 0.50MM Plates
MAWP: 150 PSI @250F
3.3Description: Engine raw water piping - Approximately 40 meters of piping measuring 150mm in diameter.
4.0USMMI Furnished Equipment:
4.1USMMI Furnished Equipment (GFE): None
4.2USMMI Furnished Material (GFM):
4.2.1 O-rings for the Steering System HPU and the Bow thruster HPU coolers.
4.2.2 Pencil zincs for Main Engine Coolers, AC Plant Heat Exchangers and refrigeration Plant Heat Exchangers & coolers
4.2.3 Head Gaskets for the Main Engine coolers, AC Plant Heat Exchangers, Refrigeration
Plant Heat Exchangers
4.3USMMI Furnished Services (GFS):None
4.4USMMI Furnished Information (GFI):
4.4.1Technical Manuals and drawing are available on board the Vessel
5.0Notes:
5.1The contractor and all subcontractors, regardless of tier must consult the General Technical Requirements (GTR) 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.
5.2The 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.
5.3The contractor shall comply with all requirements of equipment tag out program as established by COMSCINST 3540.6, as amended, section 15.2.2, Engineering Operations and Maintenance Manual. The Chief Engineer is to administer the program. Prior to the start of work, the contractor shall contact the USMMI Port Engineer and / or the Chief Engineer to coordinate the implementation of the Tag Out Program for the entire performance period of this item. The prime contractor shall be responsible for compliance by both prime and subcontractor personnel.
6.0Quality Assurance Requirements:
6.1All workmanship, materials and testing shall be in accordance with the latest ABS Rules for Building and Classing Steel Vessels. Quality Assurance requirements shall be in accordance with MSC GTR No 3 – Tests, Inspections, Trials and Certificates.
7.0Statement of work
7.1The Contractor shall contact the Chief Engineer prior to starting any work to ensure that the valves are secured and seawater system is drained
7.2Temporarily disconnect the necessary piping, heads and manifolds in order to allow for inspection of the coolers listed in paragraph 3.2.
7.2.1Allow the Chief Engineer and Port Engineer to inspect the coolers prior to cleaning.
7.3 Cleaning:
7.3.1Condenser/Heat Exchanger Heads
7.3.1.1Clean each main engine jacket water cooler headswhich are not coated with Belzona Supermetalglide 1341 by conveying ashore and blasting to SSPC-SP-10 (near white metal).
7.3.1.2The water channels for each EMD engine (parts 3 and 4 as shown on Enclosure 2.1) shall also be conveyed ashore and blasted to SSPC-SP-10 standards. Each channel measures approximately 18” length by 24” diameter and weighs approximately 85lbs each. There are two channels per cooler.
7.3.1.3Apply two coats Belzona Supermetalglide 1341 epoxy along internals of each channel and head.
7.3.1.4Clean all gasket mating surfaces and polish to accept new gaskets.
7.3.1.5Renew zincs using USMMIfurnished pencil types.
7.3.2Condenser/Heat Exchanger Piping Tubes
7.3.2.1Contractor shall procure a commercial grade power tube cleaner as well as appropriate sized nylon brushes to clean each condenser.
7.3.2.2 Each tube bundle shall be cleaned using nylon bristle brushes set in a coil, wrapped around a wear resistant polymer core.
7.3.3Heat exchanger piping cleaning – EMD Engines 1-4
7.3.3.1The contractor shall temporarily disconnect and remove the check valve on the discharge side of the raw water pump providing cooling to the heat exchanger. Clean the entire length of pipe from the check valve to the head of all zebra mussels and fouling using a commercial grade power tube cleaners and scalers.
7.3.3.2Allow the Chief Engineer to inspect each piping section after cleaning and prior to reinstalling check valve and head.
7.3.4Plate coolers
7.3.4.1The Contractor is to temporarily disconnect piping and the foundation bolts and rig all four gear oil cooler ashore to an authorized Alfa Laval repair shop.
7.3.4.2The coolers are to be disassembled, cleaned and a condition report is to be prepared with photographs and provided to the USMMI Port Engineer as to the conditions found. The USMMI Port Engineer is to be notified so that the cleaned plates can be visually inspected. All gaskets are to be provided and replaced by the subcontractor. Any additional repairs identified in the Condition Report will be handled by a change order.
7.3.4.3After all repairs are completed the coolers are to be hydrostatically tested at 1.25 times the design pressure in the presence of the USMMI Port Engineer. .
7.3.4.4After successful tests the cooler are to be returned to the ship and reinstalled using new contractor provided gaskets and stainless steel fasteners..
7.3At the completion of cleaning, the Contractor shall notify the P/E in order to schedule an inspection for both the heads and tubes with the ABS Surveyor in attendance.
7.6After inspection and approval by the Port Engineer, reassemble the units as per original installation using new USMMIprovided gaskets, new O-rings where required, new zincs where required and new contractor provided stainless steel fasteners.
7.7 Upon completion of all work accomplished, conduct a leak test using system pressure. Allow the Chief Engineer and Port Engineer to inspect for leaks. Repair all leaks as required.
7.8 Clean up all dirt and debris generated, and wipe down the immediate and adjacent spaces to the satisfaction of the Port Engineer and Chief Engineer.
7.9No additional work is to be accomplished without prior written approval by the Contracting Officer, Purchasing Manager or USMMI Port Engineer. The USMMI Contracting Officer, USMMI Purchasing Manager or USMMI Port Engineer is the only person authorized to give the Contractor authorization to proceed with growth or new work. The USMMI Port Engineer is the single point of contact authorized to address technical questions.
7.10A Completion of Work Report describing all work that was performed will be delivered to the Port Engineer upon completion of all work.
8.0General Requirements:
8.1The Contractor shall provide all labor, materials, temporary staging and tools required to accomplish this work specification, except as specified in Section 4.0.
8.2The Contractor shall remove and reinstall interferences necessary to accomplish this work specification.
8.3Inspection and acceptance of all work shall be by the Chief Engineer and the designated On-site USMMI Representative (Port Engineer).
8.4All areas involved in work or traversed by workmen or equipment shall be left clean and in good order.
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