Page 440 - Chemical process engineering design and economics
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Design of Flow Systems 421
valve shut off tightly while in service to prevent valuable or dangerous liquids
from leaking. Occasionally, a tank requires cleaning or repairs. Then the valve is
completely opened to empty the tank quickly. Another application is to isolate
equipment from the flow system for replacement or repair.
Check valves prevent back flow. The ball check valve, shown in Figure 8.3,
is particularly simple in that it has no moving parts requiring close clearances bet-
Ball Check Swing Check
Source: Reference 3.32 Source: Reference 3.32
Figure 8.3 Examples of check valves. From Ref 32 with permission.
Globe Needle
Source: Reference 8.32
Figure 8.4 Examples of throttling valves. From Ref 32 with permission.
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