HYDROSTATIC TEST OF CO2

CYLINDERS

Every 5 years you must hydrostatically test the carbon dioxide cylinders used on multiplace life rafts. However, fully charged cylinders are considered serviceable regardless of the last hydrostatic test date. If a cylinder is both due for a test and discharged, disconnect it from the raft. Obtain a new cylinder from supply as a replacement. Forward the old cylinder to supply. (Cylinders must be empty before forwarding to supply.) Before installing the new cylinder, perform the following tasks:

1. Gently tap the inverted cylinder with a small piece of wood. If any rust or other contamination falls from the cylinder, do not use it. Draw another from supply and repeat the contamination check.

2. Ensure that a siphon tube is installed on all multiplace life raft cylinders.

3. Replace the stem in the inflation assembly valve.

^4. Install a new sealing washer. Refer to NAVAIR 13-1-6.1.

Table 6-4.-Barometric Pressure Conversion Chart

^{5. Thread the} inflation valve onto the ^{cylinder and} tighten it to a torque value ^{of 600 60} inch-pounds for multiplace life raft cylinders and 400 40 inchpounds for LR-1 raft cylinders. The hydrostatic test does not apply to the LR-1 life raft cylinder.

MULTIPLACE RAFTS

Multiplace life rafts vary in size and in the quantity of equipment they carry.

CNO has established survival equipment lists as standards to be used by all concerned. These lists provide the equipment necessary for an effective 24-hour survival capability.

The body of the life raft consists of an encircling buoyant tube and a fabric bottom. The fabric sections used in the inflatable buoyant tube are incorporated in such a manner that the warp threads of the straight fabric run in a circumferential direction around the tube, and the warp threads of the bias cloth run in the opposite direction in the adjoining sections.

The fabric bottom of the raft is applied without tension across the enclosure formed by

the flotation tube, and it is attached securely to the underside.

SEAM TAPES AND PATCHES

All raft seams and patches are secured by the use of self-curing cement, applicable to the specifications listed in the Inflatable Survival Equipment Manual, NAVAIR 13-1-6.1.

No sewing or stitches are used in the seams or through the fabric of any compartment. However, sewing is permitted in the construction of patches, oarlocks, disks, flap seats, cylinder carriers, lifeline supports, handles, and pockets.

Seam repair is done only if a flotation tube does not leak; that is, if only the outer seam tape is loose or if the seam does not seal a flotation tube. If the seam tape is present and undamaged, recement the tape to the raft. If the tape is missing, measure and fit a replacement tape to the area and cement it in place. Overlap the seam tape on other seams a minimum of 1 inch.

If the tape is damaged, peel the tape from the raft. Apply toluene only as needed to loosen the tape. Avoid excessive application of toluene on the seams, and remove any spilled or excess toluene immediately.

NOTE: Do not use toluene near open flame, heat, or electrical sparks. Avoid prolonged contact with the skin or breathing the fumes. Use toluene only in well ventilated areas.

Do not touch the cleaned raft areas when handling. Clean both the pieces to be cemented with four applications of toluene. Apply the toluene with back-and-forth strokes on the first and third applications and one-waystrokes on the second and fourth. Allow the areas to dry between applications.

Prepare cement and accelerator mixture. Prepare only enough mixture to last for 8 hours, as this is the effective active period for the mixture. Dispose of any remaining mixture after 8 hours.

Using a disposable brush, apply cement to completely cover surfaces to be cemented.

Apply two coats of cement to both pieces, allowing the first coat to dry for approximately 10 minutes.

When the second coat of cement becomes tacky, place the pieces together. If the cemented area is a cut or tear, butt the edges of the damaged area before applying a patch. Roll out the bubbles using a wooden roller.

Allow the cemented area to dry for at least 48 hours, and then dust the area with talcum powder.

If the seam tape is only damaged, trim the old tape and replace it with new tape. Overlap the other seam tape a minimum of 1 inch. All tapes and patches are applied to the life raft without tension. The tape is applied in such away that an equal amount of tape width is on each side of the seam edge, which it covers.

To patch a damaged area on a life raft, select the applicable color and type of raft cloth, depending on the type of raft to be repaired. Cut a rounded patch 1 inch larger than the damaged area on all sides. Scallop the edges of the patch if it is larger than 5 inches in diameter.

If the damaged area in the floor is larger than 1 inch, patches must be applied to both sides. Intermediate maintenance activities have the prerogative to declare rafts beyond the capability of maintenance if internal patching is required.

Center the patch over the damaged area and trace an outline of the patch on the raft fabric.

Cement the patch to the damaged area in accordance with the instructions previously discussed in this section. After all repairs have been made, perform a leakage test on the raft and dust the repaired area with talcum powder.