Actuators Flashcards
The purpose of a control valve actuator?
to provide motive the force to operate a valve mechanism
What are the 4 types of actuators
-pneumatic
-hydraulic
-electric motor
-hand (manual)
what is the purpose of these hand valves?
they are used to manually position the valve in the event of air pressure failure
Why would a diaphragm actuator be used instead of a pistion actuator?
It is used when precise valve postioing is important. It is more precise because it has less friction than a piston valve.
Piston actuators generally have ______ than diagphram actuators
stroke lengths
True or false: diaphragm actuators generally withstand much greater air pressure as opposed to piston actuators
FALSE
What type of actuator is this called?
piston actuator
What type of actuator is this called?
diagphram actuator
what is the purpose of the yellow cylinder of on left side of this actuator
to indicate what what position the valve is in
What type of mechanism is this called and what does it do?
Rack and pinion mechanism.
to convert linear piston motion into rotary shaft motion. (butterfly valve ball valve etc)
what are hydarulic actuators?
actuators that use liquid pressure rather than gas pressure to move the valve mechanism
True or false?
nearly all hydraulic actuator designs use a piston rather than a diaphragm to convert liquid pressure into mechanical ( force most of the time?
true. The high pressure rating of piston actuators lends itself well to typical hydraulic system pressures
What is this called?
pilot-operated control valves
What application is pilot-operated control valves commonly used in?
gas pressure regulation.
especially for fuel gas such as proane or natural gas used to fuel large industrial burners
Where is this seen in?
Electrical Actuators
