NSW_RIB_ECP_161_Bilge_Vented_Loop_(2).pdf

For:

Contract No. USZA22-03-D-0003

Submitted by:

UNITED STATES MARINE, INC.

10011 Lorraine Road Gulfport, MS 39503

(228) 679-1005

Submitted On:

October 14, 2008

Presented to:

US SPECIAL OPERATIONS COMMAND

SOAL-NS-C (Bldg 506C) 7701 Tampa Point Blvd.

MacDill AFB, FL 33621-5323

CDRL DI-022

ECP 161

Bilge System Vented Loop Install

United States Marine, Inc.

Contract #USZA22-03-D-0003 2 ECP 161

USMI NSWRIB

ENGINEERING CHANGE PROPOSAL

Originator: D.J Malley

10011 Lorraine Rd Gulfport MS 39503

Submittal Date: 10-14-2008

Contract Number: USZA22-03-D-0003

Procuring Contracting Officer: Sandra Smith

ECP Number: ECP 161

Title: Bilge System Vented Loop Installation

Description of Change: A vented loop with silencer (consisting of a vent barb with breather vent) will be installed on each of the two aft electric bilge system discharge lines at the top of the loop prior to exiting the transom.

Reason for Change: The electric bilge pumps can become air locked, preventing them from functioning properly. A detailed review of the manufacturer's specifications for the Rule 16A (24V) 3700 bilge pump revealed that the use of a check valve in the discharge piping requires the installation of a vented loop.

CAGE Code: 0NNZ7

Specifications Affected: None

Drawings Affected: A-2, Sheet 1; A-2, Sheet 4; P-4, Sheet 3 DDP/Interim Spare Item Change: Yes

Effect on Production Schedule: None. ECP can be incorporated on production craft with no negative effect. All other craft will require the retrofit.

Contract #USZA22-03-D-0003 3 ECP 161

MODIFICATION JUSTIFICATION:

The current electric bilge pump system air locks sporadically and will not function properly. The current piping configuration allows water to remain trapped near the transom check valve which, consequentially, keeps the bilge pump from priming itself due to air trapped between. The manufacturer’s specification for the electric bilge pump states that a vented loop is required when a check valve is used in the system. A check valve is located on the discharge hose of each electric pump at the transom. Testing of the pumps with a vented loop eliminated the air lock;

however, “whistling” from the vented loop occurred when the bilge pumps were turned off. After a vent barb (USMI# 506-7010) with breather vent (USMI# 506-7009) was applied to the vent opening in the top of the vented loop, testing showed that the “whistling” was successfully eliminated. The vent barb (USMI# 506-7010) and breather vent (USMI# 506-7009) are shown on page 6 under Attachment 1 “Modification Description”.

MODIFICATION DESCRIPTION

See Attachment (1) for a detailed description.

SCHEDULE:

The ECP will be incorporated on future production craft. There is no negative effect on the production schedule. The NSWRIB production schedule will remain 14 weeks and 1 day. (This includes approved ECP's from 010 to 161). All other craft will require retrofit and each craft will take one day to complete when made available to USMI. Retrofit kits can be made available from USMI 60 days after approval of delivery order.

WEIGHT AND MOMENT IMPACT:

LCG/VCG Change with Vented Loop Components Added:

Note: * Positive value indicates a shift forward or upwards.

USMI # or OEM# DESCRIPTION QTY

UNIT

WEIGHT

TOTAL

WEIGHT

505-9008

LOOP, VENTED, MF 840, 1-1/2" BARB, 5-1/4" H X

7-3/4" W

2 0.4 0.8

506-7010 ASSEMBLY, VENT BARB, MF-846 2 0.02 0.04

506-7009 BREATHER-VENT, 1/4" NPT MALE, 3 MAX CFM, 1/2"

HEIGHT 2 0.02 0.04

634-7003 4” INSPECTION PORT 2 0.4 0.8

505-7198 CLAMP, WORM, SS #24, 1-4/16" - 2" (10/PK) 8 0.04 0.32

Total Weight Change 2 lbs

Vessel Configuration

Weight Change

(lbs)

LCG

Change* (inches)

VCG

Change* (inches)

Light Load 2.00 -0.01 0.00 Full Load 2.00 -0.01 0.00

Contract #USZA22-03-D-0003 4 ECP 161

LOGISTICS AND SPARING:

The following parts will be added to the MEL:

The following part will be deleted from the MEL:

(None)

The following list details recommended additions to the PIO list:

The following parts will be added to the DDP:

USMI# VENDOR/OEM VENDOR#/OEM# DESCRIPTION QTY U/I

505-9008 Forespar Marelon 903000

LOOP, VENTED, MF 840, 1-1/2" BARB, 5-

1/4" H X 7-3/4" W

2 EA

506-7010 Forespar Marelon 903004 ASSEMBLY, VENT BARB, MF-846 2 EA

506-7009 McMaster Carr 4471K12

BREATHER-VENT, 1/4" NPT MALE, 3 MAX

CFM, 1/2" HEIGHT

2 EA

634-7003 Lewis Marine 5063-1054 4” INSPECTION PORT 2 EA

505-7198 Gulf Belt & Die &

Gasket Co. CL-WORM-SS-24 CLAMP, WORM, SS #24, 1-4/16" - 2" (10/PK)

8 EA

The following parts list details the components that make up this ECP:

USMI# VENDOR/OEM VENDOR#/OEM# DESCRIPTION QTY U/I

505-9008 Forespar Marelon 903000

LOOP, VENTED, MF 840, 1-1/2" BARB, 5-

1/4" H X 7-3/4" W

2 EA

506-7010 Forespar Marelon 903004 ASSEMBLY, VENT BARB, MF-846 2 EA

506-7009 McMaster Carr 4471K12

BREATHER-VENT, 1/4" NPT MALE, 3 MAX

CFM, 1/2" HEIGHT

2 EA

634-7003 Lewis Marine 5063-1054 4” INSPECTION PORT 2 EA

505-7198 Gulf Belt & Die &

Gasket Co.

CL-WORM-SS-24 CLAMP, WORM, SS #24, 1-4/16" - 2" (10/PK) 8 EA

USMI # VENDOR/OEM VENDOR#/OEM# DESCRIPTION U/I

505-9008 Forespar Marelon

903000

LOOP, VENTED, MF 840, 1-1/2" BARB, 5-1/4" H X 7-

3/4" W

EA

506-7010 Forespar Marelon

903004 ASSEMBLY, VENT BARB, MF-846 EA

506-7009 McMaster Carr 4471K12

BREATHER-VENT, 1/4" NPT MALE, 3 MAX CFM,

1/2" HEIGHT

EA

634-7003 Lewis Marine 5063-1054 4” INSPECTION PORT EA

505-7198 Gulf Belt & Die & Gasket Co.

CL-WORM-SS-24 CLAMP, WORM, SS #24, 1-4/16" - 2" (10/PK) EA

USMI # VENDOR/OEM VENDOR#/OEM# DESCRIPTION U/I

505-9008 Forespar Marelon 903000

LOOP, VENTED, MF 840, 1-1/2" BARB, 5-1/4" H X 7-

3/4" W

EA

506-7010 Forespar Marelon 903004 ASSEMBLY, VENT BARB, MF-846 EA

506-7009 McMaster Carr 4471K12

BREATHER-VENT, 1/4" NPT MALE, 3 MAX CFM,

1/2" HEIGHT EA

634-7003 Lewis Marine 5063-1054 4” INSPECTION PORT EA

505-7198 Gulf Belt & Die &

Gasket Co.

CL-WORM-SS-24 CLAMP, WORM, SS #24, 1-4/16" - 2" (10/PK) EA

Contract #USZA22-03-D-0003 6 ECP 161

Attachment (1)

MODIFICATION DESCRIPTION

The vented loop installation can occur as either a retrofit or during the production sequences of a new craft. The following describes the steps to effectively install the vented loops on the discharge line.

Vented Loop Assembly - Two assemblies required per NSW RIB.

* The Rubber Duckbill Valve must be inserted with the “Duck Bill” facing towards the vented loop (as shown above) for proper operation.

Vent Barb Assembly

USMI P/N 506-7010

Breather-Vent

USMI P/N 506-7009

Hose Clamp #24 SS

USMI P/N 505-7198

Hose Clamp #24 SS

USMI P/N 505-7198

Rubber Duckbill Valve (supplied with Vented

Loop 505-9008)*

(1) Vented Loop

USMI P/N 505-9008

Contract #USZA22-03-D-0003 7 ECP 161

Vented Loop Installation:

Step 1: Remove jet hatches and locate bilge discharge hose anti-siphon loop under the gunwale in the jet room.

Location of anti-siphon loops

Detailed view of anti siphon loops

Contract #USZA22-03-D-0003 8 ECP 161

Step 2: The anti-siphon loops of the aft port and starboard bilge pump discharge line is cut at its highest point and the vented loop (505-9008) is connected to the hose and secured with two hose clamps (505-7198) on each end. The vented loop cap is removed and a vent barb assembly with duck bill valve (506-7010) is installed in place of original cap. The breather vent (506-7009) is screwed into the top of vent barb assembly to muffle whistling sound created when a bilge discharge occurs.

Step 3: Place the small angle of the template on the starboard gunwale, and slide the template against the transom bulkhead. Using the template as a guide, drill three 3/16” pilot holes for the vented loop, and one ¼” pilot hole for the center of the inspection port. Remove the template and use a 4-½” hole-saw to drill the hole for the inspection port. Repeat for the port side.

Vented loop and inspection port template.

Vented Loop Assembly (Installed in Bilge Discharge Hose)

Vented loop mount pilot holes

4-½” hole saw pilot hole for inspection port

STBD

FWD

Contract #USZA22-03-D-0003 9 ECP 161

Step 4: Jam nut three #10X1-½” stainless steel machine screws in the vented loop mounting hole locations, and install the inspection port (use 5200 adhesive to seal the bolts and silicon to seal the port). Once completed, the gunwale should look like the figure below.

Step 5: Mount the vented loop assembly to the gunwale using the three #10 machine screws installed in step 4, fender washers, and #10-24 nylon locknuts.

Vented loop as installed under gunwale

Step 6: Conduct an operational check of the aft electric bilge pumps to ensure proper operation.