We have an office argument going about the use of ball valves versus gate valves on a sewer force main.  This particular project is a 12" force main running about 2.5 miles and discharging into a manhole butterfly valves are not recommended for force mains, they tend to trap debris..Ball valves are not good for high abrasion liquids like sewage can be. 
Early in my career I designed WWT plants.  We used gate valves, plug valves, and butterfly valves.  Gate and Plug valves performed better.  Butterfly valves, as someone noted, trap debris.  If you use them post-comminutor, post-screening, or after a grinder pump, they are fine.
While any of them will sieze, gate and plug valves are easier to repair without removal.  Butterfly valves generally require removal for repair.
gate valves (resilient or double disk) are more typical on smaller forcemains and eccentric plug valves on the larger ones.

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