Flow-Guard means guarding against flow when its characteristics are detrimental. Flow-Guard is used to describe devices that guard against excess flow, such as Flow Fuses and Breather Bags. Guard against bursts, gushes, toxic spills, excess flow, and more, using products from Flow-Guard. Flow-Guard guards against flow fluctuation / pressure pulsation. You do not want to guard against flow. Flow is good! Excess flow is not.