Pipe sizing question

[TF12]

Hi,
I have limited information but maybe someone can point me in the right direction
I am installing 2 Vogt Ice machines 25,000 lbs of ice per day per system.
The refrigerant is NH3
The Two machines will share a common surge drum but I have questions
Can I have one wet suction header connecting the two in parallel?
Or should each machine have its own wet suction back up to the surge drum?
My dry suction back to the engine room will be in excess of 500'
How do you calculate the necessary line size and do I need to reduce the line as it travels out to the surge drum?

[RANGER1]

TF12 if you go to vogt ice website, download appropriate ice machine manual & if advises sizes & how to pipe up system.

[RANGER1]

http://www.vogtice.com/wordpress/wp-content/uploads/P18AL-Service-Manual.pdf
http://www.vogtice.com/wordpress/wp-content/uploads/P24A-and-P34A-Manual.pdfhttp://www.vogtice.com/wordpress/wp-content/uploads/P24AL-P34-AL-Manual-.pdf (http://www.vogtice.com/wordpress/wp-content/uploads/P24A-and-P34A-Manual.pdf)

3.17 & 3.18 in P24AL-P34AL manual give piping example.
Assuming you would have P18AL machines.

Guessing each ice machine suction 2" & main line back to slop pot 3 to 4 "
Each ice machine has to have a suction solenoid/ evaporator pressure regulator for them to harvest individually
& not allow suction pressure to get to low in each ice machine.