The（） is a smaller valve fitted in the auxiliary steam supply line, and is usually of the non-return type.

A.main steam stop valve
B.auxiliary steam stop valve
C.feed check or control valve
D.blow down valve

A.fuel valves of main engine
B.injector pump of main engine
C.safety valves of marine boiler
D.safety valves of a reciprocating pump

A.a mechanical seal
B.keyway and key
C.a nut
D.shrinkage