Scuba Equipment

1
Scuba Equipment

• Objectives
• To Learn How to Use the Equipment Necessary for
  Breathing Underwater
• To Learn How to Use It Most Efficiently
• To Learn How to do Basic Maintenance

2
Scuba Tanks

• Have Changed Little since Cousteau made his first
  dive with his Aqualung
• Manufactured in a carefully controlled process
• Each tank is tested at several points during
  manufacture

3
Selecting a Tank- Sizes and Materials

• The two metals that tanks are made from are Steel
  and Aluminum
• Most Steel tanks are 71.2 cubic feet in capacity
  (often just called 72s)
• Most Steel Tanks are rated to 2250 PSI
• Aluminum tanks usually are 80 cubic feet in
  capacity and are rated to 3000 PSI
• Tanks can be as small as 10 ft3, and as large as
  120 ft3

4
Scuba Tanks-Markings

• Each Tank is stamped during manufacture with
  markings required by the DOT
• 3AA designates steel alloy tanks
• 3AL designates aluminum alloy tanks
• The large number is the tanks serial

5
Scuba Tanks-Markings

• The manufacturers name is stamped on
• The highest rated tank pressure
• All of the Hydrostatic Test dates and the
  testers symbol (done every 5 years)
• The yearly Visual Inspection Program sticker

6
Scuba Tanks-Markings

• The yearly Visual Inspection Program sticker

7
Care and Maintenance of Scuba Tanks

• Care is mostly keeping moisture out
• Exterior should be rinsed with fresh water
• Keep at least 100 PSI in tank to keep water out
• Transport carefully, boot in first in cars, with
  tanks secured from movement

8
Care and Maintenance of Scuba Tanks

• Yearly Visual Inspections-VIPs
• Most reputable dive shops wont fill a tank that
  doesnt have a current sticker
• Inspect the tank yourself
• Look for white damp air
• Smell air for damp or oily smells
• Listen for water sloshing around inside

9
Care and Maintenance of Scuba Tanks

• Hydrostatic Testing
• Tanks must be tested every 5 years
• The test is designed to measure the elasticity of
  the metal of the tank
• The test eliminates potentially dangerous tanks
  before metal fatigue gets to the breaking point.

10
Tank Valves

• Two basic types
• Yoke Valves
• Most common, especially in U.S.
• DIN Valves
• More common in Europe.
• Allows higher fill pressures, up to 4500 PSI.

11
Tank Valves

• Two basic types of yoke valves.
• K Valves
• Simple on-off valve.
• Must use an SPG.
• J Valves
• Has second knob that controls a constant reserve
  of 500 PSI.
• Divers breathed from tank until they couldnt get
  air, then flipped the lever to return to surface.
• Did not use SPG.
• Many drowned that way.

12
Tank Valves

• Other types of yoke valves.
• YValves
• Used to hook up two regulators to a tank.
• Manifold Valve
• Used to hook two tanks to a single regulator.

13
Regulators

• Modern regulators are two stage, single hose
  regulators.
• What does a regulator regulate?
• Breathing air pressure.
• Modern regulators reduce the tank pressure down
  to ambient pressure.
• First stage (attached to tank) reduces pressure
  to about 140 PSI.
• Second stage further reduces pressure to the
  ambient or surrounding pressure.

14
Regulators

• Second stage (the one that has the mouthpiece)
  also exhausts the divers exhaled air.