Answer / rajesh.

When a fluid passes a valve the fluid velocity increases. If the speed through the valve is high enough, the pressure in the liquid may drop to a level where the fluid may start bubble or flash. The pressure recovers sufficiently and the bubbles collapse upon themselves.
This situation is extremely destructive and may wear out the trim and body parts of the valve in short time which called Cavitation.
With an increasing fluid temperature the possibility for cavitation increases.

Cavitation can be avoided by using more than one control valve or more convenient - a multistage control valve.

What is difference between sensors and transducers?

2 Answers  

---

WHEN BOTH WIRES OF THERMOCOUPLE R SHORTED WHAT IS THE OUTPUT THE TEMP ARE 0,30,250,320

13 Answers  

---

in the pipe line if the control valve fails to respond to controller action,by what means we can stop the flow in the pipe line ?

9 Answers  

---

calibration of instruments.

11 Answers   ONGC,

---

How you calibrate absolute pressure with the calibration range of 0 to 1000 0C Absolute. Please explain the procedure for calibration.

0 Answers   Petro Rabigh,

---

how to design orifice plate?what is the equation?

0 Answers   REL,

---

how is hazardous and non hazardous area classified?

2 Answers   Bhel, Power Plant, Samsung,

---

What are different types of orifice plates? State their uses.

0 Answers  

---

What is critcal speed. what is resonant frequency. why we want to cross crtcal speed on higher RPM (early).

0 Answers  

---

tion 0,50,100% equql to voltage formula?

1 Answers  

---

How many loops are there in the power plant? how many closed & open loop in the power plant ? Please give me the exact clarification?

2 Answers   Lanco, Reliance,

---

How to Calibrate Flammable gas detector in field

0 Answers  

---