in my plant 100% feedwater control v/v is air to close but
due to instrument air fail,the valve opens but instead of
drum level high its get tripped in low low drum level.the
urv of level tx is 0 and lrv is -800.pls tell me the reason.
for such behaviour.
Answer / carl_ellis
Air-to-close means that the valve fails open.
A boiler feedwater valve should 'fail open' so that the drum
level never drops too low, which can be an unsafe condition
and/or a damaging condition.
For that same reason, a boiler's feedwater valve should be
driven open on a low-low drum water alarm to prevent the
drum level from dropping too low and creating an unsafe
condition and/or a damaging condition.
Carl Ellis
Measure First
| Is This Answer Correct ? | 0 Yes | 0 No |
we have level transmitter for h2s04 storage tank capacity 10k ,always there are failure of transmitter due to failure of magnetic floats ,please come up with solutions at the earliest.
Why flow/pressure transmitter before control valve?
Why we are measuring 4-20ma? Why we are not taking 0-20ma? Plz answer this
how can check the loopchecking for valves?
HOw To Use 24V DC in Instrument?
how many type of plug are used in pneumatic control valve,name them.
1.what is the power consumption of three element drum level control in sugar industries? 2.how to reduce that?
IF ASK IN THE INTENVIEW WHAT TYPE OF BMS YOU USE?
if a dp transmitter has range 100 in H2O and flow is 20mmcf and if the flow is changed to 25 mmcf then what is the formula to determine new range of transmitter
How we will check whether the proximity, which we have is either NPN or PNP, if no data sheet or manual or any details is available to us ???
How to calibrate and check thermal mass flow meter of Make thermal instrument company inc model 60?
what is the vital subject for scoring bhel exam&what is the question pattern
Civil Engineering (5086)
Mechanical Engineering (4456)
Electrical Engineering (16639)
Electronics Communications (3918)
Chemical Engineering (1095)
Aeronautical Engineering (239)
Bio Engineering (96)
Metallurgy (361)
Industrial Engineering (259)
Instrumentation (3014)
Automobile Engineering (332)
Mechatronics Engineering (97)
Marine Engineering (124)
Power Plant Engineering (172)
Textile Engineering (575)
Production Engineering (25)
Satellite Systems Engineering (106)
Engineering AllOther (1379)