Why do direct spark ignition furnaces and hot surface ignition furnaces require redundant gas valves?
A) in case one fails to open, the other will B) so that the unit will not overheat
C) because they require more fuel D) for safety since there is no pilot safety solenoid
Question 2
Which of the following statements applies when heating a bearing with a torch during the removal process?
a. Never use a propane torch.
b. Use an aluminum ring for a heat sink.
c. Cool the bearing with a wet cloth as soon as it is removed.
d. Do not reuse a bearing removed this way.
Examples of structures in which extensive surface area is important for function.
Juglans nigra (Black Walnut tree) lower leaf surface
Blood typing and cross-reactions. The blood type depends on the presence of surface antigens ...
Cell Surface Regulators
The European Alps have lost ~30% to 40% of surface area and ~50% of volume since the 1850s.
A sphere, 0.30 m in radius, has a surface emissivity of 0.48 and is at a temp