試題詳解

16. A steam trap works automatically and is put into drain lines so that these drain off condensate automatically without passing any steam. One type of operated traps utilizes floatcontrolled needle valves to trap steam or air. Some use open floats, other ball type floats. What type of operated traps is above description?
(A) Thermostatic trap
(B) Mechanical trap
(C) Thermodynamic trap
(D) Vacuum trap