atmospheric pressure

75-80 kg/cm2

10 kg/cm2

40 kg/cm2

give maximum space

give maximum strength

withstand pressure inside boiler ,

resist intense heat in fire box

non-coking bituminous coal

brown coal

pulverised coal

coking bituminous coal

horizontal

vertical

inclined

both horizontal and vertical

one-half

one-third

one-fourth

two-fifth.