Control Valves Flashcards
Single Ported Globe Valve
Needs larger actuator
Seals easier
Double Ported Globe Valve
Smaller Actuator (more equalized pressure)
Harder to seal (due to thermal
expansion of parts)
Gate Valve
On / Off
Not good at fine control
little energy loss when open
Diaphragm Valve
for slurries (biphase products with solids)
slurries can damage other kinds of valves
poor fine control
Port Guided Globe Valve
stem can be smaller due to reduced
pressure on stem
Unbalanced Cage Guided Globe Valve
more force required due to difference in pressures
less leaks
Balanced Cage Guided Globe Valve
less force required by stem due to balanced nature
more leaks
Unbalanced Cage Guided Globe Valve Leaks
Balanced Cage Guided Globe Valve Leaks
3 way Globe Valve
for converging or diverging service
Rotary Stem Ball Valve
full bore ball valves have no restriction
when fully open
poor flow control (causes too much turbulence)
characterized or segmented versions have good
shutoff and much better flow control
Rotary Stem Butterfly Valve
Rotary Stem Disk Valve
hard to close completely
eccentric disk valve (variation) shuts
completely (called high performance butterfly valve)
Ball Valve Example
Segmented or Characterized
Ball Valve Example