flowserve boiler feed pumps 1

[jerryb722]

does anyone out there have a flowserve 4 x12 wxh-10 boiler feed pump in their plant. if so can you tell me if you had any problems w/ vibration, pipe stress, bearing, and if you found a fix. we have got a real dog of a pump, and i'm ready to use it for a boat anchor

 

[JJPellin]

Odds are that it isn't a pump problem. We don't have any pumps of that model, but have many BFW pumps that are lines now owned by Flowserve. Based on comments on another site, it sounds like you feel pipe strain is the problem. Depending on the process temperature, cold pipe strain or thermally induced pipe strain can be a severe problem. Even if the piping designers tell you the supports will direct thermal growth away from the pump, I would be skeptical. We had a pair of pumps that had bad vibration problems and ended up with cracks at the support feet on both pumps. We had the piping analyzed for thermal pipe strain and they told us it was in spec. Then I checked it in the field. I put a dial indicator on the bottom of the coupling hub with pump and piping cold and then had them heat it all up. The coupling dipped down 0.040" and then came back up to within about 0.010". We had a another designer evaluate the thermal piping growth and he found that the nozzle loading was 20X greater than API allows. You can relax cold pipe strain by cutting and rewelding. In some cases, you can wrap stress relieving elements around the pipe and heat it up enough to relax the strain. But if the supports are not designed correctly, it won't matter. The hot strain will still cause failure. Without more details about service, piping configuration, vibration data, failure bearing RCFA, etc. it is hard to comment further.