Surface Cleanliness Standards Flashcards
(126 cards)
1
Q
The most common abrasive blast standards for new steel are from?
A
NACE, SSPC, and ISO
2
Q
NACE No. 1 is?
SSPC-SP 5
A
White Metal Blast Cleaning.
3
Q
NACE No. 2 is?
SSPC-SP 10
A
Near-white metal blast cleaning.
4
Q
NACE No. 3 is?
SSPC-SP 6
A
Commercial Blast Cleaning
5
Q
NACE No. 8 is?
SSPC-SP 14
A
Industrial Blast Cleaning
6
Q
NACE No. 4 is?
SSPC-SP 7
A
Brush Off Blast Cleaning
7
Q
NACE No. 1
(SSPC-SP 5)
White Metal Blast Cleaning.
This allows Random staining on how much of the blasted surface?
A
None
8
Q
NACE No. 1
(SSPC-SP 5)
White Metal Blast Cleaning.
Level of cleanliness?
A
Complete. No oil, dust, mill scale, rust, coating, oxides, corrosion, etc.
9
Q
NACE No. 2
(SSPC-SP 10)
Near White Metal Blast Cleaning
This allows random staining on how much of the blasted surface?
A
5%
10
Q
NACE No. 2
(SSPC-SP 10)
Near White Metal Blast Cleaning
Level of cleanliness?
A
Complete. No oil, dust, mill scale, rust, coating, oxides, corrosion, etc.
11
Q
NACE No 3
(SSPC-SP 6)
Commercial Blast
Level of Cleanliness?
A
Complete. No oil, dust, mill scale, rust, coating, oxides, corrosion, etc.
12
Q
NACE No 3
(SSPC-SP 6)
Commercial Blast
This allows how much random staining?
A
33%
13
Q
NACE No 4
(SSPC-SP 7)
Brush Off
Level of Cleanliness/Random Staining Allowed?
A
Tightly adherent mill scale, rust, and coating may remain.
14
Q
NACE No 8.
(SSPC-SP 14)
Industrial Blast
Level of cleanliness?
A
Traces of tightly adherent mill scale, rust, and coating residues are permitted to remain on 10% of the each unit area.
15
Q
Acceptable variations in appearance of blasts, that do not affect surface cleanliness:
A
Type of Steel Original Surface condition. Thickness of steel. Weld metal. Mill or fabrication marks. Heat Treatment. Heat Affected Zones Blasting Abrasives. Difference in the blast pattern.
16
Q
A white metal blast (NACE No 1/ SSPC-SP5) when viewed without magnification shall be free of visible.
A
Oil Rust Grease Coating Dirt Corrosion Products Mill Scale Other foreign matter.
17
Q
A near-white metal blast (NACE No 2/SSPC-SP 10) when viewed without magnification shall be free of visible.
A
Oil Rust Grease Coating Dirt Corrosion Products Mill Scale Other foreign matter.
18
Q
A NACE No 2/SSPC-SP 10 Near White Blast shall have staining limited to no more than 1___ ___ of each unit area and may consist of 2___ ___, ___ ___/___ ___ caused by rust, mill scale or previously applied coatings.
A
- 5 percent
2. Light Shadows or Slight Streaks/Minor discolorations.
19
Q
A unit area is a __ by __ ___ area.
A
3 by 3 inch area.
20
Q
NACE No 3 (SSPC-SP 6) Commercial blast cleaning follows the same Cleanliness standards as NACE No 1 and 2 (SSPC-SP 5 and 10),
However, it allows for random staining on ___ ___ of each unit area.
A
33 percent.
21
Q
A brush off blast (NACE No 4 / SSPC-SP 7) when viewed without magnification should be free of.
A
Oil Grease Dirt Dust Loose Mill Scale, Rust and Coating.
22
Q
With a Brush Off ( NACE No 4 / SSPC-SP 7) these are allowed to remain on the surface if tightly adherent.
A
Mill Scale, Rust, and old coating.
23
Q
NACE No 8 (SSPC-SP 14) is an Industrial Blast that, when views without magnification should be free of all visible?
A
Dirt, Dust, Oil and Grease.
24
Q
An Industrial Blast (NACE No 8 / SSPC-SP 14) allows traces of tightly adherent mill scale, rust, and coating residues to remain on 1___ ___ of each unit area if 2___ are ___ ___.
Shadows, streaks and discolorations caused by stains of rust, mill scale and previously applied coating may be present on the 3___ ___ ___ ___.
A
- 10 percent.
- they are tightly adherent.
- Remainder of the surface.
25
SSPC-VIS 1 is the
Visual Guide for Abrasive Blast Cleaned Steel
26
SSPC-VIS 1 does not have photo's for A SP7 because of the wide variations in appearance when ___ ___ blast cleaning adherent mill scale is completed.
Brush-off
27
SSPC-VIS 1 does not show a photograph for A SP6 because this cannot normally be obtained when removed adherent mill scale with a ____ ___.
Commercial Blast.
28
Steel surface completely covered with adherent mill scale; little or no rust visible.
Rust Grade A
29
Rust Grade A
Steel surface completely covered with adherent mill scale; little or no rust visible.
30
Steel surface covered with both mill scale and rust.
Steel Grade B
31
Steel Grade B
Steel surface covered with both mill scale and rust.
32
Steel Grade C
Steel surface completely covered with rust; little or no pitting visible.
33
Steel surface completely covered with rust; little or no pitting visible.
Steel Grace C
34
Steel Grade D
Steel Surface completely covered with rust; pitting visible.
35
Steel Surface completely covered with rust; pitting visible.
Steel Grade D
36
Steel Grade G
Coating system applied over mill scale bearing steel ; system thoroughly weathered, thoroughly stained.
37
Coating system applied over mill scale bearing steel ; system thoroughly weathered, thoroughly stained.
Steel Grade G
38
Steel Grade G1
Extensive pinpoint rusting is present in these photo's.
39
Steel Grade G2
Moderate pitting is present in these photographs.
40
Steel Grade G3
Severe pitting is present in these photo's.
41
ISO 8501-1 contains four standards.
1. Sa 3
2. Sa 2 1/2
3. Sa 2
4. Sa 1
1. Blasting to visually clean steel.
2. Very thorough Blast Cleaning
3. Thorough Blast Cleaning
4. Light Blast
42
The quality of blast cleaning is determined ___ and photographic standards are generally used for comparison purposes.
Visually
43
There is no correlation between the degree of blast cleaning used, and the ___ ___. Nor is there a specific correlation with removal of chemical contamination. For these issues, written standards and other measuring techniques must be used.
Surface profile
44
The degree of surface roughness and the rate of cleaning depends primarily on the characteristics of the ___ ___ used.
Abrasive grit used.
45
Although blasting abrasives range wildly (from crushed walnut, slags and various metallic shots and grits, even ceramic grits) there are a there are a limited number of abrasive types in common use to prepare a surface for coating. These include?
1. Crushed Slag
2. Naturally occurring mineral grit
3. Ceramic Grit
46
Despite the widespread use of the term "Sand Blasting' sand is not listed as a grit blasting abrasive. Sharp sand is cheap and effective but it is increasingly not used throughout most of the world (Nor is any abrasive containing free silica.) due to the health hazards of ___. Workers exposed to hazardous levels of free silica during blasting may develop this very serious lung disease.
Silicosis
47
It is important to note there is some naturally occurring silica free sand that can be used for abrasive blasting. These sands do not release silica in a harmful form (i.e. 1 ____ ____) when broken up in the blasting process. Permission to use sand may be given if operators/other personnel are carefully protected from the dust and local health authorities approve it.
Free Silica
48
Crushed Slag from ____ ____ or ___ are relatively cheap abrasives.
Metallurgical processes or combustion
49
___, ___, ___, and ___ are common slags.
Copper, Nickel, coal, and aluminum
50
Crushed Slag are quite effective grits for 1___ ___ ___, but they are not generally suitable for 2 ___ ___ and ___ because they rapidly break down to dust.
1. Once only use.
| 2. Grit Reclamation and reuse.
51
Abrasives that cannot be reclaimed are often called?
Expendable abrasives.
52
There is very little ___ in copper slag since the slag is a byproduct of the copper extraction process. Most of the content is oxides of one metal or another
Copper
53
Ceramic Grits are?
Aluminum oxides and silicon carbides.
54
Ceramic Grits are relatively expensive abrasives but their use is sometimes justifiable because of their special properties. True or False?
True
55
Ceramic grits are particularly effective because their particles retain ___ ___ ___ even on hard base materials which may resist effective blasting by chilled cast iron grit.
Sharp cutting edge.
56
Ceramic Grits achieve effective cutting at ___ ___ ___ than normally used for other abrasives.
Lower blasting pressures.
57
Because ceramic grits can be used at lower blasting pressures than other abrasives, they are particularly well suited to bast thin metal surfaces which can ___ or ___ if blasted with chilled iron grit at conventional blast pressures.
Buckle or Distort
58
Because ceramic grit is virtually inert to normal ___ ___, it can safely blast stainless steel or nonferrous surfaces without causing rust staining, discoloration, or bimettalic corrosion.
Corrosive influences
59
Other factors being constant, the speed of blasting and the air consumption are directly related to the ___ of the ___.
Size of the nozzle.
60
The maximum nozzle size that can be used depends upon the capacity of the ___ ___ ___.
Compressor feeding it.
61
Maintaining nozzle size is of considerable importance. This can be a problem with normal ___ ___ nozzles which wear quite rapidly.
Cast Iron
62
More efficient blasting can be maintained with nozzles made of ___ ___, ___ ___ or ___.
Resistant allows, tungsten carbide, or ceramics.
63
The ___ ___ of the blast nozzle is extremely important.
Internal profile
64
___ ___ are generally preferred to the parallel-bore nozzles formerly used.
Venturi Nozzles
65
Venturi Nozzles have a higher ___ ___ at a more economical air consumption and result in an increase in overall blasting efficiency.
Grit Velocity
66
There are two types of blasting nozzles used in the industry today. Those are?
Straight bore and Venturi
67
Straight bore nozzles have an outlet abrasive velocity of about ___ or ___.
217 mph or 315 ft/s.
68
Straight bore nozzles tend to spread the abrasive in a large blast pattern with more ___ at the center and less at the edges.
Concentraton
69
The Venturi Nozzle has a large entrance throat, tapers gradually into a short straight section in the middle, and then flares out at the outlet end. The Venturi shape permits abrasive velocity up to ___ or ___ and an almost equal impact over the entire surface.
720 mph or 660 ft/s.
70
Venturi nozzles are the most effective shape for ___ cleaning jobs.
Tough
71
With regards to nozzles, the user should periodically check:
1. Nozzle
2. When venturi nozzles ___ they lose their efficiency.
3. Check for ___ and/or ___ nozzles. Do not use these nozzles because they can create a sever safety hazard. They also decrease blasting effectiveness.
1. Type
2. Wear
3. Cracked and/or worn nozzles.
72
Use a nozzle ___ ___ to measure wear.
Orifice gauge.
73
Some users specify that nozzle wear should not exceed 1___ ___ ___. Other users may require nozzle replacement when wear reaches 2___ ___ of the original size.
1. One nozzle size.
| 2. 50 percent.
74
Test for nozzle pressure of the optimum 1 ___ to ___ ___ using a 2___ ___ ___ ___ during the blasting operation.
1. 90-100 psi
| 2. Hypodermic Needle Pressure Gauge.
75
With the blasters agreement, wither the inspector or operator measures the pressure by inserting the needle into the hose as close as possible behind the ___ ___ while the hose is blasting with abrasive.
Blast Nozzle.
76
Choice of Nozzle size is affected by the;
1. Type of ___ to be done.
2. Volume of ___ ___ available.
3. Amount of pressure ___.
4. Type of ___ ___ being used.
5. ___ needed.
1. Work
2. Compressed Air.
3. Available
4. Blast unit
5. Velocity.
77
Longer nozzles equals more velocity, a more concentrated blast patter, and are preferred on?
Tough cleaning jobs.
78
Nozzles too large for work may waste power from ___ ___.
Undue Blasting
79
When conducting the Blast Hose Pressure Test (Hypodermic Needle Pressure Gauge Test) make sure the needle aperture faces the direction of blast flow. If the needle opening faces into the stream of abrasive, it may become clogged or damaged.
This is a tip from an experienced blaster/painter and is not found in the NACE course book.
80
Ensure workers do not use ___ as hammers, tap signals with them, or drop them.
Nozzles
81
For the safety and comfort of the blast cleaning operator, good quality work clothes are essential. These typically include:
1. ___ ___ safety boots.
2. ____
3. Strong ___ ___.
4. ___ ___ ___ ___, incorporating a replaceable visor and leather cape.
5. ___ protection.
1. Steel Toed
2. Coveralls
3. Leather Gloves
4. Air Fed Blasting Helmet/Hood
5. Hearing
82
It is important that the operator has a good supply of clean, fresh air for breathing. Two common ways to achieve this are:
1. Deliver a supply of air, at low pressure, from the ___ ___ via a filter.
2. Disadvantage: The air is the same (___ ___) quality as that used for blasting.
3. Feed in a separate supply of air, also a low pressure, from a remote ___ ____ ___ well away from any contaminated or dust laden atmosphere.
1. Blast Pot.
2. Usually Poor
3. Air-driven pump.
83
Abrasive blast cleaning at high pressure is a ___ operation.
Dangerous
84
Some safety consideration with abrasive blasting are:
1. Allow no one but the ___ in the vicinity of the blast cleaning operation.
2. Display ___ ___.
3. ___ all equipment for operational safety.
4. Post a ___ ___ (aka ___ ___) to watch for hazardous activity.
5. Ensure fitting and use of a ___ ___ cut out device.
6. Ensure that a deadman (___ ___) valve which allows the machine to be controlled at the nozzle by the operator is part of the unit.
7. Ensure that the deadman feature is always ___ and ___ during blasting operations.
1. Operator.
2. Warning Notices.
3. Test.
4. Look out (aka Pot man)
5. Deadman's switch.
6. Remote Control.
7. Operational and used.
85
Several accessories are in common use with the blast pressure pot, including:
1. ___ ___ ___ to monitor the proper balance of abrasive to the air flow and nozzle size.
2. Remote Control ___ ___ valve.
1. Abrasive Metering Valve.
| 2. Deadman Switch.
86
The operator must hold the deadman valve in the ___ ___ to pressurize, and therefore activate, the blast pot.
Closed position.
87
When the deadman switch is released, the blast machine is ___ ___, thus safeguarding the operator. If the operator becomes ill, falls, faints, trips, or drops the hose, he/she is not in danger of being hit with abrasives or the blast hose whipping around the work area.
Shut down.
88
Many consider a deadman valve cost effective because it can eliminate the need for a?
Pot man. (aka, pot tender or blaster's helper.
89
Dead man switches may operate by ___ ___ or ___.
Compressed air or electricity.
90
Compressed air operated deadman switches do not require any other power source than the compressor but may be ___ to ___, particularly when the blast hoses and nozzle are a significant distance from the blast pot.
Slow to react.
91
Electrically operated deadman switches operate instantaneously but require a power source, they are not intrinsically safe so they cannot be used in a ___ ___.
Hazardous environment.
92
Ensure the workers wear the required ___ and ___ air supplied respirators for all dry abrasive blast cleaning.
Filtered and regulated.
93
Not only the operator, but all personnel in the contaminated are should wear approved ___ ___.
Breathing apparatus.
94
Ground all equipment to prevent ___ ___.
Electric Shock
95
All participants in the surface prep process, including inspectors, should use ___ ___ in detecting potential hazards.
Common Sense.
96
Everyone has a responsibility to report any lighting, scaffolding, or equipment ___ that are safety hazards to the appropriate person.
Malfunctions
97
Knowledgeable and responsible workers ensure the safety of staging, spiders, or swing scaffolding before using them for __ or __.
Work or inspection.
98
Never get in the path of ___ ___.
Abrasive blast.
99
Abrasives particles can travel as fast as ___, with the effect of a shotgun blast.
450 mph
100
Coating inspectors should be familiar with, and when appropriate, make use of the following protective equipment.
1. Blast ___.
2. Breathing equipment such as ___.
3. Heavy protective ___ and ___.
4. ___ and ___ protection.
5. Operators may be required to ground equipment, and the coating inspector may also be required to ___ that the equipment is properly grounded.
5. Site safety must conform to applicable worker protection ___ and ___. (In the U.S. Occupational Safety and Health Administration (OSHA) regulations provide necessary guidelines. In other countries, governmental bodies have similar regulations that must be observed.)
1. Hoods
2. Respirators.
3. Clothing and Gloves.
4. Hearing and eye protection.
5. verify
101
Ambient conditions may have an effect on the abrasive blasting process as well as the blast cleaned surface before coating. Ambient Conditions include?
```
Surface Temp.
Air Temp.
Relative Humidity.
Dew Point.
Environmental exposure (e.g. Marine, industrial, etc.)
```
102
It is unwise to blast if the steel surface is much 1___ than the surrounding air. Moisture can condense on the surface and cause 2___ ___. Use a 3 ___ ___ ___ to check the substrate temp.
1. Colder
2. Flash Rusting.
3. Steel Surface Thermometer.
103
During blast operations high humidity can result in the rapid deterioration of the cleaned surface. Do not conduct final dry blast in wet or damp conditions (Rain) or when the humidity is very high, usually greater than ___ ___.
90 percent
104
Relative Humidity is defined as the amount of moisture in air, compared with the ___ ___ ___ (aka Saturation Level).
Maximum possible amount
105
If RH reaches 100%, then the air cannot support any more water vapor and any surplus vapor will appear as?
Condensation.
106
Dew Point is defined as the temperature at which ___ occurs.
Condensation.
107
If the ambient temp falls below the dew point, or some of the structure has a temp below the dew point, then ___ will occur.
Condensation.
108
Coatings applied over a wet surface generally do not ___ ___ to the substrate.
Adhere adequately
109
If abrasive blasting is done when environmental conditions are close to the 1___ ___, condensation is likely and flash rusting may occur. For this reason, coating specs normally require that application not take place while the steel temp or surrounding air is less than ___ ___ above the dew point.
1. Flash Rusting.
| 2. 5 Degrees F
110
In blast cleaning projects, it is common that some areas must remain unblasted. Typical examples include surfaces that are already painted or sensitive equipment such as valves or instruments. To protect these areas, 1___ ___ ___ using suitable templates of 2___, ___, or suitably tough masking tape firmly secured to the surface.
1. Mask them off.
| 2. Metal or rubber.
111
Affix masking materials in place before any ___ ___ begins in the area.
Blast cleaning.
112
Check masking materials on a regular basis during blasting to ensure adequate protection is maintained. At the conclusion of the blast and coating operations, ___ the ___ carefully.
Remove the masking carefully.
113
Surfaces must be free of oil and grease before blast cleaning. Blasting does not remove oil, grease, or nonvisible contaminants. Inspect all surfaces after cleaning to ensure they comply with the specification. Cleanliness after prep is important so ensure all residual traces of abrasive are ___ ___, ___, or ___ ___ before primer coating.
Blown Off, Vacuumed, or Swept away
114
Clean any scaffolding, staging, or support steel above the surface to prevent abrasives from ___ into the freshly cleaned surface or onto the newly primed surface.
Dropping.
115
After blast cleaning, clean the blasted surface to remove residual ___ and ___.
Dust and abrasive.
116
The blasted, then cleaned, surface should closely resemble the ___ ___ of the finish specified. I.e. NACE No 2.
Visual Standard
117
Dust or grit is not always completely removed, and often remains gathered in corners or crevices. The high pressures of the spray coating stream can disturb and distribute it into the film causing poorly adherent paint or an incomplete film formation. True or False?
True
118
Do not allow surfaces prepared for coating to ___ or to be ___ in any way between the end of the cleaning phase and the beginning of the coating application.
Deteriorate or be contaminated.
119
Clean grit blasted surfaces should not be ___ or ___ unless clean protective gloves are worn.
Touched or handled
120
Do not expose cleaned surfaces for prolonged periods or expose them at all to 1___ ___ either in the open or in storage. Under such conditions, 2___ and then ___ may proceed very rapidly.
1. High Humidity.
| 2. Oxidation and then rusting.
121
As far as practical, storage after blast cleaning should provide a ___, ___ environment.
Warm, Dry environment.
122
Apply coating as soon as possible ___ ___.
After blasting.
123
Commonly observed rules indicate a maximum delay of 1___ ___ after blasting and require that, if visible deterioration has occurred, he surface prep shall be 2___.
1. Four Hours
| 2. Repeated.
124
If lead is present in the coating waste or blast debris after blasting, do not ___ ___ the surface. The contractor must follow regulations regarding removing the lead.
Blow off.
125
Inspectors should be aware of and consider all the air supply issues that can lead to inadequate surface prep and the surface condition at the time of coating. Some of the things to be aware of are:
1. Inadequate ___ __.
2. ___ ___ air hoses.
3. Internal ___ ___.
4. Badly ___ machines.
5. Too small ___ on the machine.
6. Compressed air lines that are ___ or are ___ ___.
1. Air Supply
2. To Small
3. Hose Couplings.
4. Designed
5. Piping
6. bent or too long.
126
Always have a checklist that indicates the proper inspection procedure items. The following list includes some of what to focus and monitor during dry abrasive surface prep:
1. ___ ___
2. ___ of substrate.
3. Pre-blast ___ ___.
4. Shot/grit ___ ___.
5. Shot/Grit ___.
6. Condition of the abrasive blasting ___.
7. Surface ___.
8. Surface cleanliness after ___ ___.
9. Operator qualifications.
10. Safety.
1. Ambient Conditions.
2. Conditions
3. Surface cleanliness.
4. Size selection.
5. Cleanliness.
6. Equipment.
7. Surface Profile.
8. Abrasive blasting.
9
