Liferafts

Question 1

What is the inspection interval for the LRU-25/A crew raft and LRU-33/A

Answer 1

1 year leak test
36 months or every 3rd leak test will be a functional
6 months for visual

Question 2

What are the CO2 inflation assembly configurations

Answer 2

1.consists of an aluminum cylinder reinforced with overlapping carbon filaments bonded with epoxy resin
2. rated at 3500 psig+- 100 at 70 F
3. a pull force of 6-15 lbs required to actuate the inflation valve
4. overpressure rupture disk will rupture at 4500-4900 psig
5. cylinder pressure gauge utilizes a go-no-go color band to indicate
cylinder pressure
6. hydro test every 5 years

M13520.1C P 2-7, 2-8

Question 3

What is the weight of a LRU-33 raft cylinder with the combination co2 and n2 charge

Answer 3

3. 06-LBS CO2

5. 7 LBS N2

Question 4

What is used for the LRU-33 raft storage cradle

Answer 4

1x4in pine shelving

M13520.1C P 2-8

Question 5

What is the inspection interval for the mass casualty raft

Answer 5

5 year interval at the factory

1 year visual inspect at ast shop and may be enrolled as a special requirement inspection

Question 6

Condemned rafts and containers shall be utilized for training and shall be marked in contrasting color in what manner

Answer 6

“DRILL ONLY” in 4 in letters on raft floor buoyancy tubes, and containers

13520.1C 2-5

Question 7

When is a life raft considered non repairable at the unit level

Answer 7

1. Porous fabric areas, open seam or seam tape that cause leak
2. Damaged, malfunctioning, excessively corroded worn inlet
   Valve, manifold, oral inflation valve, inflate deflate valves
3. Holes or tears larger than 1 in
4. Holes or tears within 1 in of seam
5. Holes or tears on no inflatable floors larger than 7 in
6. Internal bulkhead leakage

M13520.1C P 2-4

Question 8

What type of valves are the topping off valves on the LRU-33

Answer 8

Spring loaded poppet valves

M13520.1C P 2-7

Question 9

What is the relief valve opening and closing pressures for the LRU-33

Answer 9

Opening- 3.2 psi
Closing- 2.4 psi

M13520.1C P 2-7

Question 10

What are the leak test and functional inspect intervals for the LRU-33

Answer 10

Leak- 180 days
Functional- every 6th leak test or every 36 months

M13520.1C P 2-7

Question 11

Where can you find repair procedures for life rafts

Answer 11

CGTO PG-85-00-310, Chapter 2

M13520.1C P 2-7

Question 12

What is the pull force required to inflate the LRU-33

Answer 12

6-15 lbs

M13520.1C P 2-7