电磁活门应在图表中显示，并包含一条注释，说明活门是由弹簧加载在开位还是关位。
A See the graphics for information of the solenoid valves which shall contain a note indicating the position of the valve(weather spring-loaded to its open or closed position).
B Solenoid valves indicated on the schematic shall have a notation indicating when the valve shall be spring-loaded to the open or closed position.
C Solenoid valves shall be indicated on the schematic and shall include a notation indicating whether the valve is spring-loaded to the open or closed position.