I have a steam flow DP transmitter that has output swinging. Steam valve is in

I have a steam flow DP transmitter that has output
swinging. Steam valve is in manual.I have good steam
pressure. The impulse lines have steam tracing on them. The
steam tracing has a hole in it that is blowing raw steam on
the high side impulse line only. Could this be causing the
swinging?

Question Posted / todd

1 Answers
4940 Views
Honeywell, I also Faced
E-Mail Answers

I have a steam flow DP transmitter that has output swinging. Steam valve is in manual.I have good s..

Answer / carl_ellis

Answer:
Yes, live steam on an impulse line could cause pressure swings.

Blowing live steam on an impulse line could conceivably heat
the condensate in the impulse tubing enough to boil it.
Even if it doesn't boil, a deadheaded impulse line with have
thermal syphon flow occuring as the hot spot condensate
rises and its place is taken by cooler condensate.

If boiling is occurring, then it could be intermittent
boiling with associated pressure pulses: as the steam
bubble(s) move away from the hot spot and cooler condensate
takes it place.

None of which should be happening in an impulse line.

The high side is 'seeing' these artifacts as forces on its
diaphragm which is creating pressure swings.

Carl Ellis
Measure First

Is This Answer Correct ?

2 Yes

0 No

Post New Answer

More Instrumentation Interview Questions

Can I route 110 VDC and 24 VDC in a same Duct for our Interposing relay cabinet? IF yes or NO Please provide me IEEE Std. for the same. Please i required it on Urgent basis, i need to design IRP Cabinets and we have MCC 110VDC and Our Coil side is 24VDC, Please help as soon as possible.

0 Answers Yokogawa,

how to make a calliberation for deffirential pressure

3 Answers

What is the use of temprature compensation?

0 Answers

Range 8 Kg/cm2, alarm to be set at 2Kg/cm2, at wat pressure reciever switch to be calibrated? justify the ans?

3 Answers

Explain the usage of the PLC system?

3 Answers

What are the questions asked in fresher instrumentation candidates

0 Answers Polmon,

What is the use of control cable?

0 Answers

if i change range of flow transmitter in th field then does it need to change range in dcs?

3 Answers

what should be the distance of vibration sensor & to the point where vibration to be measured Ex turbine axial displacement

3 Answers

Why Bently Nevada use negative voltage for vibration probes?

4 Answers

Where is the flow transmitter installed with respect to control valve, state reason.

1 Answers ADMA OPCO,

what does the ratio 800-400-300-200/1-1-1-1-1 in the specification of current transformer indicates?

0 Answers

For more Instrumentation Interview Questions Click Here