A control valve for carbide slag slurry
The LV1201 scrubber-pump outlet duty illustrates the selection problem inside a dry acetylene unit
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Operators were adjusting a manual valve about every ten minutes to steady the scrubber level. The automatic control valve was moving, but wear and internal leakage limited its ability to regulate the carbide-slag slurry.
KOWOV's dry-acetylene account follows the replacement of that valve at position LV1201, the scrubber-pump outlet. The case links a specific trim change to a visible operating problem: frequent manual correction of the level.
The slurry and the control position
The reported medium was a calcium-hydroxide slurry with approximately 4% solids. The existing V-type ball valve used 316 stainless steel with a Stellite-type hardfacing, described in the source as 316+STL.
Wear at the working surfaces contributed to internal leakage. As the relationship between valve movement and delivered flow changed, operators used the manual valve to help hold the scrubber level.
The percentage of solids alone does not define the abrasion. Particle size and hardness, the pressure drop and the opening range also matter. For a new selection, those values should accompany the medium description.
The ceramic C-valve trial
After technical discussions, a KOWOV FCRV ceramic C valve was installed in July 2023. The C-shaped rotor and supported geometry provide a different flow and seating arrangement from the earlier V-type valve.
The current FCRV design is intended for difficult media involving deposits, crystallization or particles. Its geometry keeps the stem outside the primary erosion path at small openings. The actual control trim, actuator and positioner still need to be matched to the process loop.
What changed in the control loop
| Observation | Earlier arrangement | Ceramic C-valve arrangement |
|---|---|---|
| Reported maximum level-fluctuation range | About 40% | About 5% |
| Operator intervention | Frequent manual correction | Steadier automatic regulation reported |
| Follow-up condition | Internal leakage associated with worn trim | No internal leakage reported after fifteen months |
These figures are observations from the plant account, not a controlled guarantee of performance in another loop. The report compares scrubber arrangements and does not provide every disturbance, tuning or operating condition behind the traces.
What transfers to another project is the inspection method: assess the control trend alongside the physical condition of the trim. A smoother level trace and an intact sealing surface tell complementary parts of the story.
From the trial to further orders
The customer ordered an additional fifteen valves in August 2024 and began further trials in related liquid and slurry duties. Each new position adds its own pressure, flow and solids conditions to the selection review.
For a similar control problem, send the process and valve-position trends, flow range, upstream and downstream pressures, temperature and solids description. Include the actuator, positioner and required shutoff condition.
KOWOV can then review the FCRV configuration against the actual loop. The hot lime-slurry control case offers another example of examining regulation and wear together.
Discuss your application
Discuss an FCRV replacement using your scrubber-level and valve-position trends
