Are there flow velocity restrictions to avoid static charge build up in pipelines?
Submitted by: AdministratorThere is an Australian standard "AS1020 (1984) - Control of undesirable Static Electricity" In it, there is a table for flammable hydrocarbons as follows:
Pipe Size (mm) Max Velocity (m/s)
10 8
25 4.9
50 3.5
100 2.5
200 1.8
400 1.3
600+ 1.0
This is based on pure hydrocarbons, and there is a correction, which can be applied for fluids of different conductivity. Methanol has a higher polarity than hydrocarbons and hence is more conductive. The resistivity of diesel is 1013 ohm-m vs 108 for methanol. In addition to this, normal piping design guidelines should however be followed, such as appropriate earthing, and ensuring exit velocities into tanks of 1 m/s.
Submitted by: Administrator
Pipe Size (mm) Max Velocity (m/s)
10 8
25 4.9
50 3.5
100 2.5
200 1.8
400 1.3
600+ 1.0
This is based on pure hydrocarbons, and there is a correction, which can be applied for fluids of different conductivity. Methanol has a higher polarity than hydrocarbons and hence is more conductive. The resistivity of diesel is 1013 ohm-m vs 108 for methanol. In addition to this, normal piping design guidelines should however be followed, such as appropriate earthing, and ensuring exit velocities into tanks of 1 m/s.
Submitted by: Administrator
Read Online Chemical Engineering Job Interview Questions And Answers
Top Chemical Engineering Questions
☺ | What is a good estimate for the absolute roughness for epoxy lined carbon steel pipe? |
☺ | For a heat exchanger, will the overall heat transfer coefficient increase along with an increase in LMTD (log mean temperature difference) around the unit? |
☺ | What is the method of determining maximum differential pressure during hydro testing of shell and tube heat exchangers? |
☺ | What is a "saltation velocity" and how is it used in designing pneumatic conveying systems? |
☺ | Why is post-weld heat treatment (stress relieving) sometimes necessary for welded vessels? |
Top Best Engineering Categories
☺ | Mechanical Engineering Interview Questions. |
☺ | Civil Engineering Interview Questions. |
☺ | Chemical Engineering Interview Questions. |
☺ | Electrical Engineering Interview Questions. |
☺ | Automobile Engineering Interview Questions. |