I guess s-tube runs smoother and maintanance friendly, easier to clean up

unless your pumping harsh mixes at high pressure c-valve is the way to go, never needs bearings and seals replaced so saves a considerable amount of money in parts and labour over the life of the pump. If you buy one invest in a flexable inspection camera from the tool shop, quickest and easiest way to double check you got all the crete out.

great write up PUMBO.  never seen a C valve

Wow. Pumbo. Awesome. I thought I had the grip on the C Valve and how our market undersold it here in North America.

Great stuff and thank you for taking the time. I got an education on it.