In illustration D031DG below, what does the single line located directly above the diamond indicate?

Which of the following is the pipe used to connect two separate piping systems o...

Which of the following is equivalent to a "barrel", which is a unit of liquid me...

What is the standard net barrel for petroleum products?

On tankers using manually operated tank valves, what does the deck hand wheel in...

On tankers with manually operated tank valves, which of the following is the typ...

Which of the following procedures would ensure proper seating of the valve when...

On many modern tankers, which of the following devices is used to reduce cargo p...

What is the purpose of the relief valve of a cargo pump?

What type of valve is usually on the discharge side of a cargo pump on a tank ve...

The cargo pump relief valve is usually piped to which of the following component...