Valves Flashcards
What is the definition of a valve?
Any mechanical devices by which flow is regulated by a part that opens, shuts, or partially restricts one or more ports or passageways
What are 2 advantages and 2 disadvantages to ball valves?
Advantage:
Low pressure drop
Small size and low weight
Disadvantage:
Fluid trapped in ball
Quick open/close May cause hydraulic hammer
What are 2 advantages and 2 disadvantages for butterfly valves?
Advantage:
Good cleaning
Low pressure drop
Disadvantage:
Seals vulnerable to erosion by high velocity flows
Requires high actuation forces
What are 2 advantages and 2 disadvantages to gate valves?
Advantage:
Low pressure drop
Useful at high temp and pressure
Disadvantage:
Partial open means prone to vibration
Requires large actuation force
What are 2 advantages and 2 disadvantages to globe valves?
Advantage:
Easily variable pressure drop
Low maintenance
Disadvantage:
More costly to purchase
Usually heavier than other of same size
Where are diaphragm pumps normally used?
Effluent or spent grain systems
High viscosity fluids or slurry mixtures
Where may gate valves be used in breweries?
Steam and water applications
Where may globe valves be used in breweries?
Wort, process water, beer systems (throttling/dynamic flow control)
List 4 objectives when selecting valves
Low cost
Good longevity
Desired service characteristics
Compatibility with controlled fluids
What are some factors in valve longevity?
Operating pressure
Operating temperature
Maintenance requirements
Frequency of actuation
What are some common uses for poppet valves?
Check valve
Pilot check
Pressure relief or bypass applications
What is the flow coefficient?
Flow rate theta value as a ratio of the corresponding pressure drop across it
