Equipment

Question 1

Open Circuit Scuba is the

Answer 1

most common type of recreational scuba equipment
because it is ease to use and maintain

when you inhale you breathe in gas from a cylinder and when you exhale it vents into the water

Question 2

Rebreathers can use a

Answer 2

closed circuit and a

semi closed circuit

they recycle usable exhaled gases and remove CO2

Question 3

Benefits of rebreathers

Answer 3

no bubbles

more effective gas use

Question 4

6 components of the recreational scuba system

Answer 4

BCD Inflation System (LPI)

Alternate Air Source (octo)

BCD

Regulator

SPG

Weights

Question 5

All rebreathers recycle ______________ instead of allowing them to be wasted into the water

Answer 5

usable gases

Question 6

3AA stamp on cylinders is for

Answer 6

Steele

Chrome alithilum steele

Question 7

Which of the following cylinder markings designates the hydrostatic test date

Answer 7

7@89

Question 8

the (+) designation that appears on ______________cylinders denotes that the cylinder may be overfilled to _______________ beyond its working pressure

Answer 8

steele

10%

Question 9

Differences between steel and aluminum cylinders are

Answer 9

thickness
capacity
pressure
corrosion resistance

Question 10

Aluminum cylinders were introduced because aluminum is a stronger metal and enables higher working pressures than in steel cylinders

True or False

Answer 10

False

Aluminum is less subject to structural weakening due to corrosion

Question 11

During a hydrostatic test a cylinder is placed in a water filled chamber. The cylinder is then filled with compressed air and the amount of expansion that occurs in the cylinder is measured by the water it displaces

True or False

Answer 11

False

The cylinder is filled with water
and the amount of expansion that occurs in the cylinder is measured by the water it displaces

Question 12

To what pressure is a scuba cylinder filled during the hyrdrostatic test?

Answer 12

5/3 ‘s of its working pressure

Question 13

Visually inspect scuba cylinders when

Answer 13

annually

replace O rings and inspect valves

Question 14

Three reasons to perform visual inspections each year

Answer 14

exterior damage

interior corrosion especially in steel cylinder

to prevent galvanic between the dissimilar metals of the cylinder and valve threads

Question 15

Under what circumstances should a scuba cylinder be visually inspected

Answer 15

if loose material is heard

red or green accumulation is seen on the first stage

once every year even if cylinder is in good condition

Question 16

When does a burst disk rupture

Answer 16

past 140% of the cylinders working pressure

Question 17

3 advantages of a open circuit demand valve regulator is

Answer 17

uses less air in a free flow system

avoids carbon dioxide buildup by reducing dead air spaces

simpler and less expensive than closed circuit systems

Question 18

Demand Valve refers to the fact that

Answer 18

the regulator will provide air - only on demand

Question 19

The first stage reduces the high pressure to an Intermediate pressure and that pressure is usually between

Answer 19

140 - 190 psi above the ambient water pressure

Question 20

The fundamental function of the first stage of an open circuit regulator is to

Answer 20

Reduce the high pressure delivered by the cylinder to an intermediate pressure

Question 21

In a regulator, a valve that tends to open in the direction of flow is referred to as ______________. This type of valve is considered to be a ___________ design.

Answer 21

downstream

fail safe

Question 22

In a regulator, a valve that tends to open in the direction of flow is referred to as ______________. This type of valve is considered to be a ___________ design.

Answer 22

downstream

fail safe