Consider a control valve action,the inlet air pressure is only 6 ksc but
physically how it can be operate against 100 ksc line fluid pressure?
Answer Posted / carl ellis
The reference to 6 ksc pressure means that the valve uses a
pneumatic actuator.
The ability of a pneumatic actuator to work against the line
pressure depends on the force that it can exert on the
valve's plug/cage/trim against the line pressure's force and
the bench setting of the spring.
A maximum of 6ksc of air inlet pressure can be exerted on
the total area of the actuator's diaphragm.
If the diaphragm area * air inlet pressure > plug area *
line pressure force + spring force, then the actuator will
move the valve plug. If not, the line pressure will move
the actuator.
A standard step in sizing a valve assembly with an actuator
is to check that the actuator can close against the maximum
line pressure and the spring setting at a given air supply
pressure. All vendors provide sizing charts for this purpose.
| Is This Answer Correct ? | 2 Yes | 0 No |
Post New Answer View All Answers
what is compensation? temprature & pressure
how many types of preheaters are in cement industry & what r they can any body explain?
Programmable Logic control.
why Fahrenheit unit of moistur analyzer transmitter
hiii.... can any one provide me previous years question paper of hindustan petroleum for instrumentation engineering???
Describe the typical instrumentation used in monitoring the performance of a shell and tube heat exchanger.
what is the criteria to decide conductor size of a cable ?
What is 3 selection available when configure the burnout protection for controller
what is cold loop? difference between hot and cold loop?
in sulfur process what is material of impulse line we use to connect with transmitter ? and does teflon affected by sulfur?
why we take %i0.0 as input for twido plc
Galvanizing.
How does a single acting, spring return ball valve actually work? Does it require continuous air supply?
How can test or measure the probe and extension cable to identify if the problem at the probe or cable or at the driver it self? (pleast notify the measuring method)
Linear amplifier.