单项选择题
A.shell and tube type B.plate type C.coil type D.conical disc type
To avoid impingement attack, care must be taken with th...
单项选择题To avoid impingement attack, care must be taken with the water （） through the tubes of the heat exchangers.
A.temperature B.velocity C.density D.viscosity
A non-return valve in the air delivery line near to the...
单项选择题A non-return valve in the air delivery line near to the compressor must be （）type similar to the compressor discharge valve.
A.the low inertia B.the high inertia C.the low velocity D.the high velocity
A （） in the air delivery line near to each compressor i...
单项选择题A （） in the air delivery line near to each compressor is essential.
A.butterfly valve B.globe valve C.gate valve D.non-return valve
