Waterjetting

Question 1

The WJ-1 (visual cleanliness) is comparable to which abrasive blast cleaning standard?

Answer 1

ISO SA 3

Question 2

A general description of robotic waterjetting includes?

Answer 2

Attaches using vacuum, cables or magnets
Vertical, horizontal or overhead surface
Controlled by a single operator
Collects in excess of 95% of the water, removed coatings and rust (waste generated)

Question 3

A typical waterjetting team consists of?

Answer 3

The nozzle operator
The pump operator
Additional operators or workers

Question 4

Waterjetting is effective for removing?

Answer 4

Surface oil and grease
Rust
Concrete (shot-crete) spatter
Existing coatings
Water soluble contaminants that cannot be otherwise removed by abrasive blasting
Barnacles or other micro-organisms for ships hulls or off-shire platform legs (underwater unit)

Question 5

Describe 2 of the considerations with regard to ‘back thrust’?

Answer 5

Causes fatigue

Should be no more than 1/3 of operators body weight

Question 6

To ensure a safe work place, before commencing the job the waterjet team should ensure that?

Answer 6

The work area is properly barricaded
Electrical equipment is protected from the water
Electrical connections are not allowed to sit in water
All fittings/hoses are in good condition/proper pressure rating
Nozzles free of obstructions
System is flushed and air removed
The dump system and all control systems are operational
Proper LOTO provisions/confined space entry requirements

Question 7

Waterjetting advantages include?

Answer 7

Worker safety
Worker air quality
Respiratory requirements may be less stringent
No dust contamination or clean up
Friendly to the environment
Relatively cost efficient
It requires less clean up

Question 8

Disadvantages of waterjetting?

Answer 8

Water jetting leaves no surface profile
Equipment is very expensive
Danger of UHP hose breaking
Danger of injection into the skin or serious cuts
Collecting and disposing of the contaminated water
Proficient operators required