Two Export Welding Gas Mixers Machine Portable Mobile Minitype
Blackboards are an essential tool in many classrooms, providing a surface for teachers to write notes, equations, and other information for students to see. While the use of blackboards has been largely replaced by digital whiteboards and other high-tech tools in some schools, they are still a common and effective teaching aid in many parts of the world. Steel Blackboard,Raw Material Blackboard,Blackboard Steel Coil,Writing Board Steel Sheet Wuxi Shengshu Metal Co., Ltd. , https://www.wuxissmetal.com21MX
Gas Mixture Proportioning Device Series
This two-element gas mixing device is specifically designed for gas shielded welding. It allows precise mixing of two gases as required for the operation, ensuring a well-proportioned gas mixture. With high proportioning accuracy and stable output pressure, this series is easy to carry and use. It is widely used in various gas shielded welding applications across railway, shipping, chemical industry, and machinery manufacturing.
21MX-1
0-50% is carbon dioxide (CO2), and the rest is argon (Ar).
±1.5
0.4-0.8
0.3
25
Rotary knob
21MX-2
0-10% is oxygen (O2), and the rest is argon (Ar).
±1.0
0.4-0.8
0.3
25
Rotary knob
21MX-3
0-30% is helium (He), and the rest is argon (Ar).
±1.5
0.4-0.8
0.3
25
Rotary knob
21MX-4
0-10% is argon (Ar), and the rest is hydrogen (H2).
±1.0
0.4-0.8
0.3
25
Rotary knob
21MX-5
0-50% is carbon dioxide (CO2), and the rest is nitrogen (N2).
±1.5
0.4-0.8
0.3
25
Rotary kn
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 22MX
Â
22MX-1
0-50%Â is carbon dioxide (CO2), and the rest is argon (Ar).
±1.5
0.4-0.8
0.3
30
Rotary knob
22MX-2
0-50%Â is carbon dioxide (CO2), and the rest is nitrogen (N2).
±1.5
0.4-0.8
0.3
30
Rotary knob
22MX-3
0-50%Â is helium (He), the rest is argon (Ar).
±1.5
0.4-0.8
0.3
30
Rotary knob
23MX
Â
Model Number
Mixted Range
Min Precision (%)
Input Pressure (MPa)
Output Pressure (MPa)
Delivery Flow (L/Min)
Ratio Method
23MX-1
0-50% is Carbon Dioxide (CO2), the rest is Argon (Ar)
±1.5
0.4-0.8
0.3
50
Rotary Knob
23MX-2
0-10% is Oxygen (O2), the rest is Argon (Ar)
±1.0
0.4-0.8
0.3
50
Rotary Knob
23MX-3
0-30% is Helium (He), the rest is Argon (Ar)
±1.0
0.4-0.8
0.3
50
Rotary Knob
23MX-4
0-10% is Hydrogen (H2), the rest is Argon (Ar)
±1.0
0.4-0.8
0.3
50
Rotary Knob
23MX-5
0-100% is Carbon Dioxide (CO2), the rest is Nitrogen (N2)
±1.5
0.4-0.8
0.3
50
Rotary Knob
As I mentioned earlier, blackboards are typically made from synthetic materials like porcelain enamel or laminate, which are more durable and easier to clean than stone. Steel is sometimes used as a base material for blackboards, but it is coated with a layer of porcelain enamel to create a smooth, non-porous writing surface.
Porcelain enamel is a type of glass that is fused onto the steel surface at high temperatures. This creates a hard, smooth surface that is resistant to scratches, stains, and other types of damage. The porcelain enamel coating also gives the blackboard its characteristic dark color, which provides a high contrast for writing with chalk or markers.
In addition to the traditional blackboard, there are also other types of writing surfaces used in classrooms, such as whiteboards, smartboards, and chalkboards. These surfaces may be made from a variety of materials, including glass, enamel, and plastic, and they may be electronic or non-electronic.
Overall, the use of blackboards and other writing surfaces in schools has evolved over time, but they remain an important part of the classroom experience for many students and teachers.