Gas flames — approximate temperature of an oxy-hydrogen flame What is the typical maximum temperature produced by an oxy-hydrogen flame under normal welding conditions?
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A1800° C
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B2100° C
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C2400° C
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D3200° C
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E—
Answer
Correct Answer: 2400° C
Explanation
Introduction / Context:Different fuel–oxygen combinations yield distinct flame temperatures. Selecting the right gas mix is important for materials that are sensitive to carbon pickup or require gentler heating.
Given Data / Assumptions:
- Flame type: oxy-hydrogen (hydrogen as fuel, oxygen as oxidizer).
- Normal tip, typical neutral adjustment.
- No special pressurised or enriched conditions.
Concept / Approach:Oxy-acetylene is hotter (around 3200° C) than oxy-hydrogen. Oxy-hydrogen flames typically peak near 2400° C to 2800° C depending on conditions. For standard exam/reference values, 2400° C is commonly accepted as the nominal figure.
Step-by-Step Solution:Identify flame pair: H2 + O2.Recall typical range: roughly 2400° C to 2800° C.Select the closest standard figure in the options: 2400° C.
Verification / Alternative check:Handbooks list oxy-hydrogen with lower temperature than oxy-acetylene; its clean flame is useful for aluminium soldering and certain brazing tasks.
Why Other Options Are Wrong:
- 1800° C and 2100° C: lower than typical oxy-hydrogen maxima.
- 3200° C: characteristic of oxy-acetylene, not oxy-hydrogen.
Common Pitfalls:Confusing oxy-hydrogen with oxy-acetylene; the latter is significantly hotter but may be unsuitable where carbon pickup must be avoided.
Final Answer:2400° C