The function of the bypass valve on the self-contained breathing apparatus is to（）.
1、On the day of the accident, part of th
On the day of the accident, part of the old road ______.A was damagedB was broadened to make traffic easierC was under repairD was closed to cars
2、The function of the piston compression
The function of the piston compression rings used in a diesel engine is to （）Aseal the space between the piston and linerBtransmit heat from the piston to the cylinder linerCreduce the amount of combustion gas blow-byDall of the above
3、When the starting air valve closes on
When the starting air valve closes on one cylinder, another starting air valve has （） opened on another cylinder whose piston has just commenced its downward stroke.AjustBnearlyCmerelyDalready
4、The valve on the discharge side of a c
The valve on the discharge side of a cargo pump on a tanker will usually be a（）.Abutterfly valveBspectacle valveCcheck valveDglobe valve
5、The purpose of the purge valve at the
The purpose of the purge valve at the top of the condenser in a refrigerating system is to（）Aremove any air that may accumulate in the sys...
6、The expansion valve on a Freon system
The expansion valve on a Freon system controls the （）.Asuperheat of the gas leaving the compressorBback pressure in the evaporatorCtemperature of the iceboxDsuperheat of the gas leaving the evaporator