poppet valve

mechanical valve of the corliss, sleeve, rotary or semirotary type

disc or feather type

any of the above

start-stop motor

constant speed unloader

relief valve

variable speed

2 kg/cm2

6 kg/cm2

10 kg/cm2

14.7 kg/cm2

lower power consumption per unit of air delivered

higher volumetric efficiency

decreased discharge temperature

all of the above.

better lubrication is possible advantages of multistage

more loss of air due to leakage past the cylinder

mechanical balance is better

air can be cooled perfectly in between