exhaust valve(n = noun.artifact) - a valve through which burned gases from a cylinder escape into the exhaust manifold;
is a kind of valve
is a part of exhaust, exhaust system

aortic valve, atrioventricular valve, ball valve, bicuspid valve, blow valve, butterfly valve, cardiac valve, clack valve, clapper valve, escape valve, exhaust, exhaust fan, exhaust fumes, exhaust hood, exhaust manifold, exhaust pipe, exhaust system, foot valve, heart valve, ileocecal valve, intake valve, kingston valve, left atrioventricular valve, mitral valve, mitral valve prolapse, mitral valve stenosis, pilot valve, poppet valve, pulmonary valve, pyloric valve, rectifying valve, relief valve, right atrioventricular valve, safety valve, semilunar valve, shunt valve, slide valve, sluice valve, thermionic valve, throttle valve, tricuspid valve, valve, valve rocker