PWS-REV1_N4044326Q0002.pdf

USNS Yukon

( TAO 202 )

AUXILIARY MACHINERY RFQ N4044326Q0002

PWS CATEGORY "A" 2025-12-17

Distilling plant Plate Cooler maintenance Wasson, Robert

0514 - 1

1.0 ABSTRACT

1.1 Provide technical services to disassemble, inspect, clean and renew plate packs for the ships Freshwater Generators (distilling plants).

2.0 REFERENCES/ENCLOSURES:

2.1 TECHNICAL MANUAL, TM T9531-AJ-MMC-010_0 DISTILLING PLANT

2.2 NAVSEA DWG. 185-8495617 Evaporators Replacement Arrangements & Structural

2.3 L-T8635-COT-010_2_0 ASSEMBLY OF PLATE PACK ON AQUA, INSTRUCTION

2.4 MIL-STD-2073-1E CHANGE 4 DEPARTMENT OF DEFENSE STANDARD

PRACTICE FOR MILITARY PACKAGING

3.0 ITEM LOCATION/DESCRIPTION

3.1 Contractor’s Facility.

3.2 POP 1/1/2026 -1/10/2026

4.0 GOVERNMENT FURNISHED EQUIPMENT/MATERIAL/SERVICES:

Gaskets Needed for Two Evaps:

Alfa Laval Nomen P/N Qty Plate Gaskets 3900703306 154 Plate Gaskets 3900703406 154 End Gaskets 3900703506 4 End Gaskets 3900703306 4 Gasket Glue 9844000200 2 Containers

5.0 NOTES:

5.1 None.

6.0 QUALITY ASSURANCE REQUIREMENTS: See 7.5

7.0 STATEMENT OF WORK REQUIRED

AUXILIARY MACHINERY RFQ N4044326Q0002

0514 - 2

7.1 Inspect all plates in the plate pack. Reject any plates that are holed or damaged beyond use. If the plates are stuck to each other punch them with your hands. Never use any tools or similar as the plates risk getting permanently damaged and has to be replaced.

7.2 Remove Old Gaskets from the Plates. Set both end plates aside. Pull the old gasketing from all the plates. Stubborn or hardened gasketing that remains can be scraped off with screw driver or similar tool but take care not to puncture the plate. Grind away any sharp corners on the screw driver blade or tool you are using. Stubborn traces of gasketing can also be removed using a wire brush in a power drill. It is unnecessary to remove the thin film of gasket cement remaining on the plates.

7.3 Inspect Plates. Scale not removed by the acid cleaning can be cleaned off at this time.

Loose scale can be flaked off by holding the plate by the ends and flexing. Take care not to kink or bend the plate. Clean remaining slime and marine growth with soap and water. If plates are still scaled, soak in a descaling bath of AC-2 (at pH 2.0). When plates are free of all traces of scale and slime, thoroughly rinse and dry. (To obtain a pH of 2.0 with AC-2, use 0.14 oz. of AC-2 for each gallon of water: or 1.06 grams for each liter of water).

7.3.1 Contractor shall inspect the plates prior to reassembly. Contractor shall submit a report for other conditions found unserviceable to the MSCREP.

7.3.2 Reinstall end plates and ensure that plates are tightened evenly.

7.4 INSTALL GASKETS ON PLATES

7.4.1 Gaskets are furnished in full patterns and cemented intact to all plates in the same way. On plates to be turned, the gasket will be cut as instructed later.

7.4.2 The gaskets will be cemented in place with contact cement (Part No. 872-7532).

Work with it in a well ventilated area. Stir the cement well and transfer a quantity into a plastic squeeze -bottle (e.g. ketchup bottle) with a tip that may be cut to obtain a 1/8" bead. Cement may also be applied with a brush.

7.4.3 Look at the short dimples that surround all the holes like rays. One pair of holes is surrounded by rays wider than the other pair. Stack all the plates so that the holes with the wider rays are nearest you.

7.4.4 Lay a l/8” bead of cement down the middle of the grooves that will receive the gasket.

7.4.5 Press the gasket in place, flat surface down, angular side up. The full circles in the gasket are to surround the holes with the wider dimples. Continue in the same way with the remaining plates, including the two set apart. As each is finished, stack it on top the previous one.

7.4.6 Add the extra gasketing to the two end plates set apart (wall plate and blind plate). These will be strips in the two empty diagonal channels providing the "X" pattern that will completely seal off the top holes.

AUXILIARY MACHINERY RFQ N4044326Q0002

0514 - 3

7.4.6.1 Measure the distance in the open channel from the ridge of the diagonal gasketing to the ridge of the gasketing along the top. Cut the strips to this measure, angling both ends and· taper-cutting the bottom of either end so it fits perfectly with the gasketing already in place without gaps.

7.4.6.2 Cement the two strips in place, providing enough cement at either end to fill any gaps and to create a complete, unbroken and securely sealed gasket.

7.4.7 Place the two plates on top of the others. Lay a weighted sheet of metal or wood on top of the stack to provide uniform pressure on each gasket and to keep it in place as the cement is drying. Allow at least a half hour drying time.

7.4.8 Inspect the cover plate. Grind off any corrosion.

7.5 CUT GASKETS FOR EVERY OTHER PLATE.

7.5.1 Set the blind and wall plates aside. They are not part of this procedure. Of the remaining plates, take exactly one half of them and stack them, same as you did to apply the gaskets. That is, holes with wider rays near you.

7.5.2 Cut the gaskets on these plates according to the illustration in Reference 1. If this is the condenser bundle (figure 3), cut away the entire strip between the two full circle parts of the gasket and the diagonal piece leading to the point between the upper and lower holes. If this is the evaporator bundle (figure 4), note that only four pieces, each 2" long, are cut out of the strip between the two full circle parts of the gasket (provide a template or guide to simplify this cutting). The diagonal piece is cut away same as for the condenser bundle.

7.5.3 Cutting is most efficiently done and least likely to damage the plates with a diagonal wire cutter. Lift the gasket from the plate just enough to slip the cutter jaw underneath and snip. Discard the unwanted strip. Firm down the cut ends of the gasket on the plate.

7.5.4 The plates in the other half of the stack are not cut. Neither are the wall or blind plates. You should now have an equal number of plates with a full gasket and with a cut gasket, plus one wall plate and one blind plate each with full gasketing plus added gasketing to make the “X"

CAUTION:

In cutting the gaskets avoid cutting into the circular part or into the point between the upper and lower holes. To do so will create a gap destroying the full seal the gasket is to provide in these areas.

7.6 STACK THE PLATES

7.6.1 All gasket sides of the plates face into the shell.

7.6.2 Beginning with the wall plate, apply a light coating of food grade silicone spray or oil to the gasket. This allows easier disassembly of the plates for the next

AUXILIARY MACHINERY RFQ N4044326Q0002

0514 - 4 repair. With the gasket facing into the shell and full circle gasketing down, slide the plate in on the side brackets until the gasket contacts the shell wall.

7.6.3 Continue with the remaining plates, applying the lubricant, then sliding each plate onto the stack in proper position and order:

7.6.3.1 Following the wall plate comes a full gasket plate, full circle gasketing down.

7.6.3.2 After each full gasket plate comes a cut gasket plate turned 180 degrees so that the cut and full circle gasketing are up.

7.6.3.3 Continue, alternating full and cut gasket plates in proper position until all plates have been lubricated and stacked, blind plate last, with its full circle gasketing down.

7.7 Place the plate stack in a crate designed to protect the stack. Please a single plate stack in each crate for eventual transfer to the ship.

8.0 GENERAL REQUIREMENTS

None Additional

7.7 Place the plate stack in a crate designed to protect the stack. Please a single plate stack in each crate for eventual transfer to the ship.