CanadianIce
27-02-2010, 11:43 AM
Hi Guys
I ran into a problem that I haven't encountered before, while overhauling a Howden WRV 204/165. Enerything was going well until I installed the slide valve. The farther it was pushed into the load position, from 50% to 100% the more resistence was felt until it finally stuck,I had to temporarily install the piston so I could draw it back out. From 50% to 0% it moves with a slight resistence. Installed the guide bracket thinking that this would complete the alignment even though I never had to do this before; however, this did not cure the problem. I loosened off the injection tube cover and the slide valve released and moved smoothly.Tightened the injection tube again and the slide valve bound up again. Removed the injection tube completely and inspected. It appears the last time this machine was overhauled, the tube may have been damaged and was built up then machined down to original diameter. Removed the slide valve and inspected, no signs of wear or misalignment. Checked the new PTFE seal that runs over the injection tube. Nothing unusual there. Slid the tube into the slide valve on the bench and it appeared to move smoothly but if I move the tube slightly out of alignment, it would bind as expected. I believe the injection tube is slightly bent due to the earlier machine work. The customer complained that this compressor would load but wouldn't unload all the time. I didn't get the opportunity to test the slide valve when the compressor was being dismantled. Any suggestions, thoughts or similar experiences?
Thanks
C Ice
I ran into a problem that I haven't encountered before, while overhauling a Howden WRV 204/165. Enerything was going well until I installed the slide valve. The farther it was pushed into the load position, from 50% to 100% the more resistence was felt until it finally stuck,I had to temporarily install the piston so I could draw it back out. From 50% to 0% it moves with a slight resistence. Installed the guide bracket thinking that this would complete the alignment even though I never had to do this before; however, this did not cure the problem. I loosened off the injection tube cover and the slide valve released and moved smoothly.Tightened the injection tube again and the slide valve bound up again. Removed the injection tube completely and inspected. It appears the last time this machine was overhauled, the tube may have been damaged and was built up then machined down to original diameter. Removed the slide valve and inspected, no signs of wear or misalignment. Checked the new PTFE seal that runs over the injection tube. Nothing unusual there. Slid the tube into the slide valve on the bench and it appeared to move smoothly but if I move the tube slightly out of alignment, it would bind as expected. I believe the injection tube is slightly bent due to the earlier machine work. The customer complained that this compressor would load but wouldn't unload all the time. I didn't get the opportunity to test the slide valve when the compressor was being dismantled. Any suggestions, thoughts or similar experiences?
Thanks
C Ice