Misunderstanding 1: Personal protective equipment may be worn or not worn. Experts pointed out that personal protective equipment can eliminate or reduce the impact of occupational hazards on workers' health. The Occupational Disease Prevention Law stipulates that employers must provide workers with protective equipment that meets the requirements. At the same time, workers are obliged to wear protective equipment.
Misunderstanding 2: No odor in the workshop, you can not wear personal protective equipment
Experts pointed out that many of the harmful gases are colorless, odorless, tasteless, and do not have any alertness and do not feel it. Even if it is odorous, there are limitations and individual differences in the sensory organs' perception of the outside world. Therefore, excessive belief in feelings may lead to occupational poisoning.
Myth #3: Gauze masks can be used to prevent dust
Ordinary gauze masks cannot be used as dust masks. The gauze masks we use today are cheap, sweat-absorbent in the summer, and warm in the winter. However, such masks (even if they are 16 layers thick) cannot protect against the hazards of respiratory dust from pneumoconiosis. Special dust masks are required for dust protection.
Myth 4: Medical Masks Used to Prevent Drugs
Medical masks can prevent disease from spreading through droplets, but they cannot filter toxic gases. For different poisons, use different respirator masks. General volatile organic gases can use activated carbon respirator.
Myth 5: Dust masks washing and reuse
Dust mask filter material can not be washed. The high-efficiency filters used in dust masks are usually non-woven materials, and some rely on electrostatic charges on fibers to filter respiratory dust. After washing, the microstructure of the filter material is impaired, cracks and holes that are invisible to the naked eye occur, electrostatic charges are also greatly lost, and the filtration performance is severely degraded.
Protective equipment is a passive protective measure. In any case, it should first adopt advanced production technology, do a good job of engineering protection facilities to actively prevent occupational diseases, and consider it as a protection facility if it cannot completely eliminate the occupational hazards. Workers are equipped with appropriate personal protective equipment. It is worth noting that personal protective equipment is not a panacea, and any personal protective equipment has its applicability, and it has limitations. It needs to consider the use of the environment and the scope of application of protective equipment.
China Labor Insurance Network
In Petro and chemical industry for flange connections Stud Bolts and Hex Bolts are used.
The quantity of bolts for a flange connection will be given by the number of bolt holes in a flange, diameter and length of bolts is dependent of flange type and Pressure Class of flange.
Stud Bolt length are defined in Asme B16.5 standard. The length in inches is equal to the effective thread length measured parallel to the axis, from the first to the first thread without the chamfers (points). First thread is defined as the intersection of the major diameter of the thread with the base of the point.
1) | Standards: |
Based on DIN & ANSI & JIS & IFI and per drwing |
2) | Material: | carbon steel, alloy steel, stainless steel |
3) | bolt Size: | M4-M42,3/8"--7/8" |
4) | bolt Surface: | Plain,Zinc ,HDG,DAC,Geomet |
5) | bolt Thread: | UNC, UNF, Metric Thread |
6) | bolt Quality control : | ISO 9001 |
7) | bolt Package : | Small box ,Poly Bag,Carton+Pallet |
Grades of Stud Bolts
Below a table with materials and grades for flanges, thread rods (bolts) and nuts, arranged on design temperature, flanges, thread rods and recommended nuts.
DESIGN TEMP. |
FLANGES |
GRADE THREAD RODS |
GRADE NUTS |
-195° to 102°C |
ASTM A182 Gr. F304, F304L, F316, F316L, F321, F347 |
A320 Gr.B8 Class2 | A194 Gr.8A |
-101° to -47°C |
ASTM A350 Gr.LF3 |
A320 Gr.L7 | A194 Gr.7 |
-46° to -30°C |
ASTM A350 Gr.LF2 |
A320 Gr.L7 | A194 Gr.7 |
-29° to 427°C | ASTM A105 | A193 Gr.B7 | A194 Gr.2H |
428° to 537°C |
ASTM A182 Gr.F11, F22 |
A193 Gr.B16 | A194 Gr.2H |
538° to 648°C |
ASTM A182 Gr.F11, F22 |
A193 Gr.B8 Class1 | A194 Gr.8A |
649° to 815°C |
ASTM A182 Gr. F304H, F316H |
A193 Gr.B8 Class1 | A194 Gr.8A |
DESIGN TEMP. |
FLG'S |
GRADE THREAD RODS |
GRADE NUTS |
Stud Bolts, Heavy Nuts, Stud Bolts With 2 Nuts, Hex Bolts, 2H HDG Nuts, Galvanized Bolts and Nuts
Shijiazhuang Bang dong Pipeline Technology Co,Ltd. , https://www.bd-pipefitting.com