Answer / santosh nanavati

We are doing the impulse tubing work on HP &/LP side DP
transmitter for level measurement of atmospheric close or
open vessel as per the process application. If the LP side
of tubing is filled with suitable fluid (water or process
fluid), it is called wet leg. Under this circumtances, the
transmitter zero condition will be towards negative
pressure range equivalent to the pressure head of filled
fluid in the LP side tubing. Vice versa if side of tubing
is not filled any fluid & kept empty i.e.dry, it is called
as dry leg. Under this condition,the transmitter zero
condition will not be towards negative pressure range.

Answer / sabry

If the impulse line connected to the low side of the differential pressure instrument is filled with a suitable fluid, it's called (wet leg).

If the impulse line is empty, it's called (dry leg).

Dry leg & Wet leg is a technique used in differential pressure measuremnt for 2 main reasons:

1 - We use (wet leg) to prevent the dangerous fluid from harming the sensitive instrument.

2 - In closed tank application, we use (wet leg) to prevent vapour condenstion due to temperature variation, so we get a stable/accurate measurement.

Good Luck

Ahmed Sabry
I&C Senior Engineer
Cell:+2 (0122) 1367310

Answer / ranish

Generally dry leg means without water ex: temperature
measurement thermo meter with out cloth or shield directily
to atm and with cloth ( we want to make it wet for
measurement)and subjected to atm or process

by ranish

What is CNC

1 Answers  

---

How does temperature bath work? How does coil gets heated only by applying some current?

0 Answers   Process Control Technologies,

---

hiii.... can any one provide me previous years question paper of hindustan petroleum for instrumentation engineering???

0 Answers  

---

What are the key components of control loop?

1 Answers  

---

how to check electrical health of vibration probe?

1 Answers  

---

How to calibrate the magnetic flow meter and how to correct the flow if it is showing more flow.

5 Answers   Bohra Industries Limited, TCL,

---

What is the differaence between PLC and DCS?

6 Answers  

---

how to define the P,I,D value in tuning pid loops in online.

1 Answers   Thermax,

---

For what reason would you possibly be compelled to make use of a Smith Predictor. Explain the idea behind the operation of this device.

0 Answers  

---

what is the reason for flow fluctuations happen on differential flow transmitter during in service

2 Answers  

---

How to convert gpm into inches of eater.I nerd formula with example so pls help me.

1 Answers  

---

cascade controller is feed back or feed forward or both

4 Answers  

---