Auto-recirc Valve Sticking 1

[Engineer6512]

We have a number of Automatic Recirculation valves in service for minimum flow protection on centrifugal pumps. Service is water condensate at ~330 F.

The issue that we are having is that there is scale buildup on the inside of the valve and it is causing the recirculation plunger to stick, hence causing maintenance downtime. Has anyone else experienced this problem? If these valves can't handle a little bit of scale, how could they possibly handle a more harsh fluid such as one with entrained solids? Is it possible that the manufacturer's tolerances were too low in the manufacturing of this valve? It is an AGI valve.

Any suggestions would be appreciated.

 

[JLSeagull]

Many applications are poorly matched with the selected valves. Cage style control valves are great. However, in the upstream oil production business entrained sand is not a good match for cage style trim.

For each valve furnish the maintenance history to the manufacturer. Include the current process conditions along with the original specification data. Advise of the water properties, total disolved solids, hardness, etc. Request the manufacturer to propose modifications to resolve the problems.

 

[abscott]

I have never used the AGI Automatic Recirculation valves but they do appear to be fairly close-tolerance devices and scale in the system could cause sticking. I agree with JLSeagull - contact the manufacturer and see if they offer a "flushing connection" as an option or field modification.

Valves designed to handle slurries generally have a "flushing connection" to which is piped a small but constant feed of liquid that flushes particles away from critical parts.
Regards,
ABScott