Typical admission pressure to a steam engine chest In traditional reciprocating steam engines supplied with superheated steam, the steam from the boiler is commonly admitted to the steam chest at approximately what pressure (rounded to the nearest option below)?

Introduction / Context:
Historic and instructional examples of simple or compound reciprocating steam engines typically cite moderate admission pressures compared with modern water-tube power boilers. Understanding the typical pressure band helps frame valve gear design, cylinder sizing, and lubrication needs.

Given Data / Assumptions:

• Conventional steam engines for industrial or marine service (non-supercritical, non-ultra-high-pressure).
• Superheated steam improves dryness fraction and reduces cylinder condensation.
• Educational references often illustrate ranges near 7–14 bar (≈7–14 atmospheres).

Concept / Approach:
While higher pressures exist in specialized applications, many classical engines operated near 10 bar gauge, sometimes up to 12–16 bar. Selecting the closest discrete option reflects the prevalent instructional figure, recognizing that exact values depend on design and era.

Step-by-Step Solution:
Identify typical instructional range: roughly 7–14 atm.Compare with options: 10 atm aligns centrally with that range.Hence choose 10 atmospheres as the representative admission pressure.Note: actual installations might differ, but the question seeks a typical textbook value.

Verification / Alternative check:
Classic training manuals and solved examples often assume 10 atm admission for sizing exercises, corroborating the chosen option.

Why Other Options Are Wrong:
20–40 atm are feasible but were less common for traditional reciprocating engines; 5 atm is rather low for efficient power output with practical engine sizes.

Common Pitfalls:
Assuming all boilers for engines operate at the much higher pressures used in large modern turbines; conflating absolute and gauge pressures when reading “atmospheres.”

Final Answer:
10 atmospheres