Condensed D022 Exam

Question 1

40F to Celsius

Answer 1

5/9 x (F-32)
.556 x (8)
= 4.4 Celsius

Question 2

40C to Fahrenheit

Answer 2

= (9/5 x C) + 32
= (1.8 x 40) + 32
= 104 Fahrenheit

Question 3

40C to Kelvin

Answer 3

C+ 273
= 313 Kelvin

Question 4

40F to Rankin

Answer 4

F + 460
=500 Rankin

Question 5

Healthy Reminders

Answer 5

25% is 25/100 or 0.25

250ppm is 250/1,000,000 or 0.00025

ppm to decimal move it back 6 places
ppm to % move it back 4 places

400ppm is 0.0004
650ppm is 0.065%

Question 6

Fun Fact
*useless info

Answer 6

Gas reclaim systems have an average loss of 5 liters/min

Question 7

Normal gas consumption at 140m

Answer 7

35lpm x 15b
=525liters or 0.525m3

Question 8

Normal gas consumption at 120fsw

Answer 8

120/33 +1= 4.64ata
1.25ft3/min x 4.64 =
= 5.8ft3/min

Question 9

64bottle quad charges to 200bar, 50L cylinders.
How much gas is available?

Answer 9

64 x 50 x 200 = 640,000L
=640m3

Question 10

Note: total volume don’t mean shit, available gas does

Answer 10

Re: a quad charged to 200bar
- you still need to overcome bottom pressure, ex 140m dive requires 15bar
- still need 10bar to drive the reg
-plus a safety factor

Looking at changing quads around 40bar.
You can go lower with shallow surface dives

Question 11

16 x 50L quad charged to 180bar
To be changed over at 40bar
Diver is working at 100msw
How long can the Diver work for?

Answer 11

180bar - 40bar =140bar
140bar x 50L x 16 = 112,000L

Diver 35Lpm x 11 = 385Lpm

112,000/385 = 290.9
290.9/60 = 4.85
0.85 x 60 = 51min
4hrs 51min

Question 12

Imperial
A quad contains 22,400ft3 @ 3000psi
Gauge now reads 2400psi, change the quad over at 500psi.
How much gas is available?

Answer 12

FGV= vol when full x (available pressure/pressure when full)

22,400 x (1900/3000)
22,400 x 0.63
=14,186.7 ft3
Or
22,400 / 3000 x 1,900

Question 13

Suitable compressor?
-LP comp supplies 8ft3/min @250psi
-2divers @ 80fsw

Answer 13

Pressure Required:
80fsw/33+1= 3.42ata
+10ata for reg
=13.42ata

13.42ata x 14.7psi
=197.27psi (All Good)

Volume Required
3.42ata x 1.25ft3 x 2divers = 8.56ft3/min
(No Joy)

Compressor can’t supply enough volume

Question 14

Bailout endurance
Diver working at 180msw and has a 12L bottle charged to 180bar
How long will it last in an emergency?

Answer 14

40Lpm metric 1.5ft3 imperial

2180bar -10reg -19bar depth = 151bar available
151bar x 12L = 1812L

19 x 40Lpm = 760Lpm

1812/760 = 2.38 (0.38x60)=22.8
=2min 23secs

Question 15

What is the breathing rate for BIBS?
Imp and metric

Answer 15

0.7ft3/min
20L/min

In sat you should have enough gas to provide 4hrs breathing on BIBS per Diver for each mix.

Question 16

Give me the formula for Final pressure after temperature corrections

Answer 16

Final Pressure = Initial Pressure x Final Temp (R or K)
—————————————————
Initial Temperature (R or K)

Make sure you convert to temperature absolute.