2019 Valve list NOAA Fairweather Dry docking.docx

1. INTENT

1.1 This item is to remove, overhaul, and reinstall sea valves on the NOAA Ship Fairweather.

2. REFERENCES

2.1 Drawing: FA S0201-1, General Arrangements

2.2 Drawing: FA S4805-1, Salt Water Cooling System

2.3 Drawing: FA S4823-1, Sea Connections

3. GOVERNMENT FURNISHED EQUIPMENT (GFE)

3.1 None

4. REQUIREMENTS

4.1 Fabricate and install new valve tags for each valve listed in Table 520-1.

i. Tags shall be stainless steel.

ii. Tags shall be embossed with the valve number and system as shown in Table 520-1

iii. For Valves without a number associated with then contact the chief engineer.

b. Any deviations from valves shown in Table 520-1 shall be the subject of a CFR.

c. Prior to disassembling and overhauling a valve, the Contractor may, at their option and at no additional cost to the Government, renew the valve with an identical valve. If this option is exercised, the new valve must be tested and meet the same acceptance criteria as prescribed herein for overhauled valves. If a valve is determined after disassembly to be non-repairable, the Government will negotiate an equitable cost adjustment, limited to the difference between the cost of the new valve and the costs which would have been incurred had the valve been overhauled. For valves of 3-inch IPS size and below, the cost adjustment will be limited to the costs incurred associated with disassembling the valves.

d. Whenever a transducer sea chest valve is required to be removed for overhaul, extreme care must be taken to prevent damaging the transducer assembly. Remove and reinstall the transducer assembly in accordance with the transducer manufacturer’s technical manual, a copy of which will be provided by the COTR within 48 hours after being requested.

NOAA SHIP FAIRWEATHER

ITEM 15200

SEA VALVE OVERHAUL

ITEM-15200

PAGE-1

Table 520-1 – Listing of Sea Valves

e. Overhaul valves noted above as follows:

i. Remove valves from the ship to a suitable machine shop for overhaul, test, and inspection.

ii. Tag each valve prior to removing from the ship.

iii. Completely disassemble each valve. Matchmark valve parts.

iv. Thoroughly clean bonnets, stems, discs, gates, globes, seats, bodies, and other metal parts to bright metal.

v. Clean and chase all valve stem threads. Check stems for straightness.

1. Straighten stems to within 0.002 inch total indicator runout (TIR).

2. Polish stems to a 32 Root-Mean-Square (RMS) finish in way of packing surface and remove all raised edges.

vi. Visually inspect all parts, including all fasteners, for deterioration and other defects.

vii. Clean dress, and true gasket mating surfaces.

viii. Check the disc-to-seat, globe-to-seat, and plug-to-bore contact fits using the bluing transfer method. Final contact fits shall be demonstrated to the COR and ABS Surveyor. Machine, grind, lap, spot-in, and recheck contact fits as necessary to obtain the following contacts:

1. Globe, globe angle, and globe stop-check valves shall have a 360- degree continuous globe-to-seat contact with a bluing transfer line not exceeding 1/16-inch width.

2. Gate valves shall have a 360-degree continuous gate-to-seat contact with a bluing transfer line which does not exceed 3/16-inch width. The transfer line shall appear within the lower 50-percent of the gate seating surface at the top and bottom of the gate.

3. Plug valves shall have a minimum 80-percent plug-to-bore surface contact, evenly distributed over 100-percent of the area.

4. Swing-check valves shall have a 360-degree continuous disc-to-seat contact.

ix. If unable to obtain the above specified contact fits by machining, grinding, and lapping, renew the globes, plugs, discs, gates, and renewable seats. Contractor may, at their option and at no additional cost to the Government, renew globes, plugs, discs, gates, and renewable seats after initial inspections and before machining, grinding, or lapping the existing parts to obtain the required contact fits.

x. Reassemble each valve following successful contact tests.

1. Insure discs, gates, and plugs are in the half-open position during reassembly to avoid damaging seats or binding stems.

2. Renew all gaskets, fasteners, rubber seals, and non-metallic seats.

3. In butterfly valves, renew boots, O-rings, O-ring fasteners, and Teflon bushings.

4. Renew valve stem packing in feed water, condensate, and steam valves with packing conforming to MIL-P-24503 and DOD-P- 24583.

5. Renew valve stem packing in all other valves with packing conforming to MIL-P-24396, Type B.

f. Inspect all studs, bolts, and nuts in line and bonnet flanges of non-ferrous sea valves to determine the material. If the fasteners are not nickel-copper (Monel), submit a CFR giving the actual material, condition, recommendations, and price proposal to renew with Monel fasteners.

g. Coat the interior of each steel valve, excluding seating and polished surfaces, with the same epoxy primer used on the underwater body.

h. Perform the following hydrostatic tests after reassembling or renewing each valve. Final hydrostatic tests shall be performed in the presence of the COR and ABS Surveyor. Hydrostatic tests shall be performed as follows:

i. All tests shall be performed using clean water as the test medium. Unless otherwise specified, the test pressure shall be 150-percent of the maximum operating pressure of the system from which the valve was removed, but not less than 50 psig.

ii. With the valve in the open position, test each valve body for 10 minutes. No leakage is allowed.

iii. Seat each plug and butterfly valve with hand force. Seat all other valves using the torque valves listed in the following table as the maximum allowable seating force applied to the hand wheel.

Pounds) on Rim of Handwheel

pounds.

iv. Test each globe, angle globe, and globe stop-check valve by applying test pressure in the direction tending to open the valve. Test each butterfly, gate, and plug valve by applying test pressure alternately on both sides of the disc, gate, or plug. Hold test pressure for a minimum of 3 minutes if there is no leakage. If there is evidence of leakage, hold the test pressure and measure the leakage rate.

v. Test each globe stop-check valve and swing check valve by applying test pressure in the direction tending to close the valve (back pressure) for a minimum of 5 minutes. If leakage occurs, hold the test pressure and measure the leakage rate. Globe stop-check valves shall be tested with the stems in the open position. The test back pressure for valves having a pressure rating of 150 psig and below shall be 50 psig, and for valves having a pressure rating over 150 psig shall be 100 psig.

vi. The seat leakage shall not exceed the following:

1. Check valve back pressure tests: for valve up to and including 2 inches, the leakage rate shall not exceed 25 cc/hour/inch diameter. For valves 2-1/2 to 10 inches, the leakage rate shall not exceed 50 cc/hour/inch diameter. For valves over 10 inches, the leakage rate shall not exceed 100 cc/hour/inch diameter.

2. Soft-seated valves: no leakage shall be permitted.

3. Metal-to-metal seated valves: for valves less than 1 inch, the leakage rate shall not exceed 10 cc/hour. For larger valves, the leakage rate shall not exceed 10 cc/hour/inch of nominal pipe size.

vii. Any valve which fails a seat leakage test shall be renewed or overhauled and retested until an acceptable test is performed.

i. Remove all waster pieces and spool pieces installed between the sea valves and the ship’s hull. Thoroughly clean the waster and spool pieces and inspect for deterioration or other defective conditions and submit CFR with inspection results. Inspect all fasteners and submit a CFR same as specified above for sea valves. Reinstall waster pieces and spool pieces following successful inspection.

i. In the event the section of piping between the hull and the valve is not removable, clean and hydrostatically test the section of piping to 150 psig for 5 minutes. Any sign of leakage or deformation constitutes a failed test. Correction of a failed section of piping shall be the subject of a CFR.

j. Mechanically route out piping for sea chest vents.

k. Reinstall each valve after tests have been accepted by the COR and ABS Surveyor.

i. Install new flange gaskets.

l. Prepare and paint all new and modified areas to match original.

5. TEST/ REPORTS/ INSPECTIONS

a. The Contractor shall establish, document, and maintain an effective quality assurance system to ensure and verify that the material, processes, and procedures used comply with the requirements.

b. Prior to requesting the COR to witness the final bluing contact inspection or the final acceptance hydrostatic tests of a valve, the Contractor shall perform preliminary inspections and tests which meet the acceptance criteria stated in this Work Item.

c. After acceptable preliminary inspections and tests have been conducted, the Contractor shall notify the COR and conduct final acceptance bluing contact inspection and final acceptance hydrostatic tests of each valve in the presence of the COR and ABS surveyor.

6. NOTES/SHIPS CONDITIONS/ PHOTOGRAPH

a. None