Elbow Erosion Problems

An unscheduled shutdown of a production platform can cost Millions of Dollars a day in lost production

Most unscheduled production platform shutdowns are not caused by equipment failures, but are caused by elbow erosion.

Almost all crude oil or natural gas being extracted from a well contains sand and rock particles.

These sand and rock particles under high pressure and flow conditions become very erosive as the fluid makes a turn through an elbow.

After an elbow erodes through, the producer not only has to shut down production, but they also have safety, environmental, and clean up expenses.

To prevent elbow erosion the only solutions available were to buy thicker walled elbows; weld on the elbows to make them thicker where they guessed the break through would occur; or replace the elbow every time there was a system shutdown, whether the elbow needed replacing or not.

CRV® IS THE SOLUTION.

The CRV® eliminates the flow separation that causes erosion and the fluid travels in a helical path through the elbow

Any droplets or particles are borne along by the fluid as in a straight length of pipe, and the acceleration and focusing effects are absent

Extended life of elbows/ less downtime

Erosion commonly occurs in elbows and turns within piping systems. Damage often occurs when the pipe line is carrying solid particulates, slurries, or two phase flow, such as wet steam. In a plain elbow, the flow is accelerated and directed toward the outer wall of the elbow, which focuses high speed particulates or droplets on a restricted region. Severe wear begins to occur at that point.

Installing a CRV® upstream of an elbow eliminates flow separation and creates a smooth aerodynamic flow with its vanes to ensure full rotation of all components in the fluid as a solid body around the turn. As a result, particulates and droplets are carried along with the flow much the same as in a straight piece of pipe, which shows little erosion in the same service. In addition, the entire cross-sectional area of the elbow is available for flow and the maximum fluid velocity reached is much lower than in a plain elbow.



As fluid flows through an elbow, the centrifugal forces are inversely proportional to the radius of the elbow’s curvature. A vacuum is created on the inside radius of the elbow and a high stagnation pressure appears on the outside pipe wall.

A CRV® placed prior to the bend would have prevented the erosion shown at the outlet of the elbow. It has been determined that if the flow streamlines travel an equal distance when going around the bend of an elbow, the fluid will not be subject to acceleration or flashing. 

Example of elbow savings with installation of CRV® 

Paper mill - wet steam

Replaced elbow every 3 weeks:  cost $150,000  

Savings since installation of elbow:  over $3 million

Refinery blowdown - spent catalyst

Replaced elbow 3 times a year:  cost $300,000/day of lost production

Savings since installation over $4 million 

The CRV® vanes aerodynamic design, as shown below, eliminates erosion in gas-liquid, two-phase flow applications. In slurry or gas-particulate applications, the CRV® can be hardened, surface treated or manufactured in an appropriate material whose hardness is greater than that of the particulates (see BORON DIFFUSED CRV®).

The CRV® blade leading edge has a zero-angle of attack with an aerodynamic contour along its length to generate rotation of the fluid.





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Our flow conditioners are custom made to specifically address each piping issue offering the greatest achievable flow correction.