30.F.06 Breathing supply hoses.
- Breathing air supply hoses must be suitable for breathing gas service or must be specifically manufactured for SSA use. Hoses must have a maximum allowable working pressure equal to or greater than supply pressure plus 150 psi.
- Breathing air supply hoses must have connectors made of corrosion resistant materials and have a working pressure at least equal to the working pressure of the hose to which they are attached: connectors must not be able to become accidentally disengaged.
- Umbilicals must be marked, beginning at the divers end, in 10 ft (3 m) increments to 100 ft (30.5 m) and in 50 ft (15.2 m) increments thereafter. > See Table 30-1. USACE in-house dive teams must use the following umbilical marking system found in the ADCI Consensus Standard 006 in order to assure consistency and interoperability:
| Distance (from diver’s end) | Marking | |
|---|---|---|
| 10 ft [3 m] | one white band | |
| 20 ft [6.1 m] | two white bands | |
| 30 ft [9.2 m] | three white bands | |
| 40 ft [12.2 m] | four white bands | |
| 50 ft [15.2 m] | one yellow band | |
| 60 ft [18.3 m] | 1 yellow/1 white | |
| 70 ft [21.3 m] | 1 yellow/2 white | |
| 80 ft [24.4 m] | 1 yellow/3 white | |
| 90 ft [27.4 m] | 1 yellow/4 white | |
| 100 ft [30.5 m] | 1 red band | |
| 150 ft [45.7 m] | 1 red/1 yellow | |
| 200 ft [61 m] | 2 red bands | |
| 250 ft [76.2 m] | 2 red/1 yellow | |
| 300 ft [91.5 m] | 3 red bands | |
- Umbilicals must have a nominal breaking strength of 1000 lb (453.6 kg) and must be made of kink resistant materials.
- Hoses must be tested prior to being placed into initial service and after any repair, modification, or alteration, and at least every 12 months to 1.5 times the working pressure. Umbilical assemblies must be tensile tested at the same time intervals by subjecting each hose-to-fitting connection to a 200 lb axial load.
- When breathing gas hoses are not in use, their open ends must be closed by capping.
- The umbilical assembly used for the standby diver must be of sufficient length to reach the primary diver at the furthest distance he can proceed from the dive station or beyond.
- Umbilicals must be carefully tended to maintain them and the diver clear of hazards such as propellers (including those of ROV's) or intakes present in the diving zone, so that the diver or umbilical cannot be drawn into them.
30.F.07 SSA and mixed-gas helmets and masks must have a non-return valve at the attachment between the helmet or mask and hose which will close readily and also have an exhaust valve.
- Helmets and masks must have a minimum ventilation rate capacity of 4.5 ft3 (2.1 L/s) (actual) at the depth at which they are operated.
- The use of Jack Brown masks is prohibited on SSA operations unless it incorporates electronic communication and a means of incorporating a diver carried bailout system.
Note: For each 50 ft (15.2 m) thereafter the sequence continues by increasing the number of red bands at each even increment of 100 ft (30.5 m). In cases where the umbilical color matches an above band color, a reasonable substitute may be used (contrasting outline on same-color tape, contrasting diagonal pattern, replacement with color not used above).
30.F.08 SSA and mixed-gas helmets and masks must be capable of supporting a reserve breathing supply which can be immediately turned on by the diver in event of loss of air.
30.F.09 SSA and mixed-gas helmets and masks must be capable of supporting a two-way or four-way diver-surface communication system.
Knowledge Check Choose the best answer for the question.
30-16. Umbilicals must have a nominal breaking strength of _____ and must be made of kink resistant materials.
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