OGPMS

  Cheng Rotation Vane

Cheng Rotation Vane (CRV)

Application:
  • Pump
  • Elbows Erosion and Noise
  • Process Equipments and Condensers
  • Compressor
  • Water Hammer
  • Flow Meter
  • Control and Check Valves
  • Exhaust
Cheng Fluid Systems
The Flow Conditioning Technology Experts In Piping

Is dedicated to solving fluid flow problem by using our technology and experience along with our patented product called Cheng Rotation Vane (CRV®).

In piping and flow systems, when fluids move through pipe fitting such as elbows, tees, U-joints, manifolds and sudden expansions, the fluids becomes turbulent, causing noise, vibration, separation, accelerated and reverse flows.

If these pipe fittings are used next to pumps, flow meters, compressors, control valves, valves and process equipment, the equipments will experience failures with unscheduled downtime, lost of production, excessive repair cost, loss of flow, head and efficiency. All costing Money $$$$.

 Did You Know That:-
95% of All Pumps Cavitate to a certain Degree?


95% of All Industrial Explosions, fires, Leaks are caused by Eroding Pipe Elbows, Leaking Pump and Control Valve?

The CRV technology consists of a specially designed set of stationary vanes in a cylindrical body, which is placed at the upstream side on an elbow or Tee in piping system. The CRV eliminates the elbow induced turbulence which negatively impacts the performance of pumps, compressors, control valves, flow meters, etc.

The CRV imparts to the Fluid (Gas or Liquid) a gyroscopic motion, which counteracts the elbow induced gyroscopic motion and enables the fluid to negotiate the turn through the elbow uniformly and then exit the elbow with a flat velocity profile.

This results in an even distribution of the fluid through any cross section of the elbow and transforms the elbow into the equivalent of a straight section of pipe.


With CRV Comparison: Top view of a double-suction pump showing how a plain elbow (a) creates cavitation, while (b) promotes an even fluid distribution.



Cheng Rotation Vane

Materials of Construction
The CRV® can be manufactured from most commercially available materials, pipe diameters, pipe schedules and end connections. N-stamped units are available for nuclear applications. Special internal coatings and finishes are also available.




Above: A 10 inch CRV welded to the upstream side of a short radius elbow.

An instantaneous picture of water flowing through an elbow. The colored dyes trace the fluid motion which is determined by the flow rate and the gyroscopic turbulence caused by the elbow. Note that the separations occupy a large percent of the flow area. (See velocity vector plot Fig. 1A on the right.)

The CRV causes a prerotation of the water before it enters the elbow. This gyroscopic motion initiated by the CRV to the fluid, will cancel the gyroscopic effects caused by the elbow, and will produce a complete uniform flow at the exit of the elbow. (See velocity vector plot Fig. 1B on the right)
Applications


Typical cavitation induced elbow erosion that developed in power plant over a span of only two month.

Problem:
- Frequent elbow erosion which is caused by particular or two-phase flows
- Unsafe elbow erosion conditions causing leakage of toxic, volatile, or unsafe fluids

Solution: Use CRV

Benefits:
- Extended life of elbows/less downtime and more reliability
- No more environment spillage, clean up or reporting problems caused by elbow erosion
- Safer operating conditions
(nuclear plants)



In check valve systems with upstream close-coupled elbows, harmful high amplitude pressure burst can be eliminated by installing a CRV upstream of the elbow.

Problem:
- Chatter from check valves, when they are close coupled to an upstream elbow
- Excessive disc pin wear and breakage due to the chatter
- Poor sealing due to disc pin and valve seat wear

Solution: Use CRV

Benefits:
- Eliminates elbow induced flow turbulence in check valves
- Extends disc pin and valve seat life
- Improves sealing reliability
- Elbow induced noise and vibration are eliminated


The expense of the meter increases as the length of the required piping between the elbow and meter decreases and conversely the piping length increases as the expense of the meter decreases.

Placing a CRV before the elbow will reduce the amount of pipe length required between the elbow and meter, to one to three pipe diameters. 		Problem:
- Inaccurate flow measurements
- Lack of space for proper meter installation
- trapped fluids in dangerous chemical concentrations

Solution: Use CRV

Benefits:
- Accurate flow measurements
- More compact pipe layout
- Eliminates trapping of chemical species



©ogpms.com. All rights reserved.
HOME | About Us | Services & Maintenance | Contact Us
Valves | FRP Fans | Oil & Grease | Industrial Filter | FRP Grating | Welding Equipment | Vacuum Pump | Pneumatic Components | Caster Wheels | Piping | Cheng Rotation Vane