Scuba Cylinders Part 2

Question 1

What four things are you looking for, when checking the O-ring in the tank valve?

Answer 1

You’re Checking to make sure that the O-ring is in one piece, then checking for fraying, nicks, or cracks.

❝Listen for a leak, you can even try splashing water on the pressurized connection and look for bubbles❞

Question 2

What is the most common type of valve used in aluminum and low-pressure steel scuba tanks?

Answer 2

The most common type of valve is the classic yoke K-valve.

Question 3

If you hear an air leak that isn’t coming from the O-ring, what would you check next and how would you check this?

Answer 3

You will probably need to check the valve-to-tank seal, by submerging the tank (regulators connected) and look for bubbles to locate a leak.

Question 4

What is a VIP sticker?

Answer 4

The VIP (visual inspection sticker) notifies the user of the month and year that the scuba cylinder had its last inspection. The VIP is usually valid for one year in most countries.

❝Some operators record the info in a log book instead of on a sticker. If you don’t see one ask.❞

Question 5

What does a visual inspection entail?

Answer 5

The VIP is designed to find any mechanical or corrosion damage to the cylinder, both inside and out. Including cuts, gouges, dents, and bulges or signs of heat damage. The interior is inspected for debris, water, corrosion, pitting, thread integrity, and internal neck cracks (in aluminum cylinders).

❝ If corrosion is found, it may be necessary to “tumble” the tank — a process that involves insertion of abrasive material, and then rolling the tank to remove the corrosion❞

Question 6

What is the process used to make Steel cylinders called?

Answer 6

Steel cylinders are made using a process called “deep draw”.

Question 7

what is the process used to make aluminum cylinders called?

Answer 7

Aluminum cylinders are made using a process called “backward extrusion.”

Question 8

What does the Hydrostatic test entail?

Answer 8

It typically involves filling the cylinder with water, placing it in a water-filled pressure chamber, and measuring the expansion of the cylinder as pressure is applied. Hydrostatic test pressures vary depending on the cylinder material.

❝If the permanent expansion of a cylinder is 10 percent or more, the cylinder is condemned and removed from service❞.

Question 9

How often does a scuba cylinder need a hydrostatic test?

Answer 9

Every five years.

Question 10

When would a scuba cylinder need an additional inspection?

Answer 10

Any time a cylinder sustains physical damage or is exposed to high temperatures, the integrity of the cylinder is suspect, and an additional hydrostatic test is warranted.

❝Markings will include, the month, inspectors stamp and year.❞

Question 11

What markings on a scuba cylinder represent a steel designation?

Answer 11

Steel tanks have a 3AA designation

Question 12

Why shouldn’t you completely empty a scuba cylinder?

Answer 12

Relieving all the pressure in a wet environment can allow moisture to enter the cylinder.

Question 13

What markings on a scuba cylinder represent an aluminum designation?

Answer 13

Aluminum cylinders carry a 3AL designation.

Question 14

What markings does a

Question 15

What do the markings, DOT or TC mean on a scuba cylinder?

Answer 15

“DOT” means the department of transport on U.S.-manufactured cylinders, and Transport Canada or “TC” for those made in Canada.

Question 16

What are the two tests a scuba cylinder must have?

Answer 16

A scuba cylinder must be visually inspected and hydrostatically tested on a regular basis.

Question 18

What should you include in a scuba cylinders regular maintanance?

Answer 18

Part of your regular maintenance for scuba cylinders should include, washing with a warm, soapy water to remove salts and other contaminants, removed any boot’s to check for corrosion underneath, visually check for pitting, corrosion, dents, cracks or any damage.

Question 19

What gasses can you have your scuba cylinders filled with?

Answer 19

Aside from air, reputable filling stations can provide nitrox, oxygen, sometimes helium (for trimix) and even argon to meet the needs of nitrox and technical divers.

❝If you have the wrong gas mix in your scuba cylinder it can have severe consequences, make sure you know what’s in your cylinder❞.

Question 20

What are the rules when transporting scuba cylinders?

Answer 20

Make sure the cylinder is adequately secured during transportation. Never leave a cylinder unattended in an upright position (if it falls over, it can hurt someone or cause damage to the tank and regulators) laying the cylinder on its side could be inadequate, especially in a van.

❝Car, truck or boat where accelerations, decelerations, turns, and bumps can cause a cylinder to roll❞.