On drum level, why we are using air to close Control valve?

Question Posted / govindam

4 Answers
7733 Views
L&T, I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

On drum level, why we are using air to close Control valve?..

Answer / carl_ellis

If the valve's actuator is Air-to-Close, what state does it
fail-safe state?

Check out the article, "How to destroy a boiler - Part 1"
at this link:
http://www.nationalboard.org/index.aspx?pageID=164&ID=238

and scroll down a couple pages to the section entitled "Low
Water Conditions".

The description will provide details that help you
understand what the fail-safe state due to the loss of a
control signal on a boiler feedwater control valve should
be.

Carl Ellis
Measure First

Is This Answer Correct ?

4 Yes

3 No

On drum level, why we are using air to close Control valve?..

Answer / swastik d. u

If any problem in your
compressor, sudden stoppage
of air valve get opened. by
this we can maintain drum
level.

Is This Answer Correct ?

1 Yes

1 No

On drum level, why we are using air to close Control valve?..

Answer / sanjay k

It means we used air failed to open condition to avoide
starvation in boiler.
At any condtion water must be kept in boler and in drum.
in case air fail the valve shold open and water goes in
boler.

Is This Answer Correct ?

0 Yes

1 No

On drum level, why we are using air to close Control valve?..

Answer / govindam

i need answer

Is This Answer Correct ?

1 Yes

4 No

Post New Answer

More Instrumentation Interview Questions

If a control valve is hunting means means if we are giving 50% to the cv, the cv will open at 51% then slowly slwoly it will reaches 49% , then it will reaches again 50%, this type of action occured frequntly.. so what to do for solve this problem. The possible cause is in volume booster or positioner's relay.. positioner is double acting .. and make siemens..sipart.The cv is double acting and mounted for anti surge operation, it having 4 nos. volume booster, one sov, one positioner, etc..?

2 Answers Gujarat Fluorochemicals Limited (GFL), Shell,

full process of gas turbin?

0 Answers

how we can measure the interface level?is it possible to measure interface level with dp or pressure transmitter?

2 Answers

How to calculate the Range of level transmitter ?

1 Answers CPCL, Sejong, SSPL,

Why we are using DPT(Differential Pressure Transmitter) in separator instead of level trasmitter?

0 Answers

How to calibrate an pressure gauge with yantrika test bench?

0 Answers

Senior engineer's please help me, what is Loop Checking and Loop test? and write difference also? soon urgent