Do not confuse hose elongation under pressure with coupling slippage. If the chalk line returns to near its original position, no slippage has occurred and the assembly is satisfactory. If there is any doubt, perform a second test. If doubt persists after the second test, reject the assembly.

Air Test

Hose assemblies intended for gas or air service must also be tested with air or nitrogen at 100 psi and the assembly immersed in water. Random bubbles may appear over the hose and in the fitting area when the assembly is first pressurized. Do not construe this as a defect. However, if the bubbles persist in forming at a steady rate at any particular point on the hose, reject the assembly.

Installation of Flexible Hose Assemblies

After completion of tests, proceed as follows:

1. Install as soon as possible.

2. Do not leave the hose assembly around on decks or on docks where they can be subjected to any form of abuse.

3. Make up hose assemblies as late as possible during the availability schedule to minimize the chances of damage while the ship is being overhauled.

4. Install plastic dust caps, plugs, or tape ends to protect threaded areas until the hose assembly is installed.

When installing flexible base connections, observe the following requirements:

1. Ensure each leg of hose is free of twist between end fittings.

2. Ensure the fixed piping near the flexible configuration is properly supported so that it does not vibrate from the resiliently mounted equipment.

3. Ensure the configurations are clear of all surrounding structures and remain so when resiliently mounted equipment moves through its maximum excursion under shock.

4. Locate flexible connections as close as possible to the sound-mounted unit.

5. Support the free elbow of the configuration with an approved pipe hanger so as not to sag or otherwise unduly stress or distort the configuration.

6. Do not appreciably change the alignment of the hose configuration between the unpressurized and pressurized conditions. If you do, you could cause misalignment or improper support at the fixed end.

Figure 9-52.-Hose assembly identification tags.

7. Obtain metal hose assembly identification tags (fig 9-52) from your local SIMA and secure them onto one of the legs of the hose configuration. The tag is made of a noncorroding material. Do not remove or alter the tag once it is attached.

8. Leave the configuration in a condition where one end can hang down unsupported during installation or dismantling of piping. Otherwise, you can damage the hose wire reinforcement.

Periodic Inspection By Ship's Force

No less than once a quarter, preferably about once a month, visually inspect all flexible piping connections to determine whether any signs of weakness or unusual conditions exist. Inspect the hose in other systems semiannually. To assist you when performing this inspection, you should compile a checkoff list of hose assemblies and locations for your assigned spaces or equipment. This list will consist of all flexible devices installed (and their locations) together with a list of inspections to be performed on each flexible device. When you perform the listed inspections, note the following:

1. Evidence of leakage at fitting ends.

2. Discoloration of fittings (possible indication wire reinforcement is rusting).

3. Slippage of hose out of fitting.

4. Twisting of hose or other distortion or unusual appearance.

5. Cracking of outer rubber cover.

6. Rubber cover rubbed thin by abrasion or chafing.

7. High pulsations, fluid hammer, or whipping caused by pressure pulsations.

8. Large vibrations due to improper supports at the fixed end.

9. Large area of hose covered with paint. (The intent of this requirement is to eliminate having the flexible hose connections deliberately painted. The hose does not have to be replaced if a few paint drops inadvertently fall onto it. Do not attempt to clean off dried paint from the hose.)

10. Check hangers to ensure they have not broken off', become distorted, or been otherwise damaged.

11. Soft spots or bulges on hose body (indicates weakening of bond between outer rubber cover and wire braid or deterioration of the reinforcing wire).

12. If results of visual inspection indicates weakening of hose or fittings, or makes hose configuration suspect, replace the hose immediately, if at all possible. Keep under surveillance while under pressure until it is replaced.

13. If necessary to remove a flexible hose configuration from the system, examine the interior of the hose for cracks or other signs of deterioration of the inner liner. Do not damage the liner by trying to dislodge sea growth. Do not remove the end fittings from any section of hose that is to be installed.

14. Presence of identification tag.

Storage

The following guidelines are recommended for proper storage of hose and fittings:

Hose-Hose should be stored in a dark, dry atmosphere away from electrical equipment; temperature should not exceed 125"F. Storage in straight lengths is preferred, but if hose is to be coiled, take care to ensure the diameter of the bend is not less than 3 feet. To prevent damage during storage, wrap the hose with burlap or other suitable material.

Reusable end fittings-Protect all threads with tape or other suitable material, and wrap the entire fitting in a protective covering to prevent nicking or other damage,

Shelf Life

The following are shelf life requirements for hose and reusable end fittings:

Hose-Do not install reinforced rubber hose that is over 4 years old from the date of manufacture. This time is measured from the quarter and year of manufacture but does not include the quarter year of manufacture. Consider the shelf life of hose ended upon installation aboard ship. To ensure against its accidental use, dispose of any hose not installed that has exceeded the above shelf life.

Reusable end fittings-There is no shelf life for end fittings. They should be replaced on an individual basis when examination makes them suspect.

Servicing

No servicing or maintenance is required since hose or fittings must be replaced at the slightest suspicion of potential failure. If a fitting is removed from a section of hose, that hose section must not be reused, regardless of its service life.

Service Life of Rubber Hose

All rubber hose has a periodic replacement time. All flexible rubber hose connections will be replaced every 5 years ( t 6 months) in critical systems and every 12 years in noncritical systems. Wire braided Teflon hose has no specified shelf or service life. Its replacement is based on inspection of the hose for excessive wear or damage.