I need help understanding what SL and CL150 mean in the markings on the graphite gasket, which read SL DN20 CL150
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This post was last edited by yuchenchf on 2015-8-21 at 11:19. I would like to ask: 1) What do SL and CL150 mean in the designation SL DN20 CL150 for graphite gaskets? 2》The steam traps installed on the steam pipelines, as well as the ordinary bolts at the flange connections, are greatly affected by thermal expansion and contraction. I would like to ask whether it is necessary to tighten those bolts again after steam supply is stopped for a while and then restarted Is there any good way to address this phenomenon? I hope you can provide an answer. Thank you!
It needs to be tightened again to reduce the impact of thermal expansion and contraction
SL was not found; it should be a flange according to American standards. It’s likely the same as the domestic standard SO (a wafer butt-welded flange). As for CL150, it represents the nominal pressure per American standards – CL150 equals PN20. This means that this gasket is suitable for DN20, PN20 wafer butt-welded flanges, as well as screws used on steam traps, flanges, blind flanges, etc. Normally, grade 8.8 screws should be used; ordinary grades will also work fine. It’s advisable to tighten the screws after steam is introduced, but if the steam pressure and temperature are not high, it may not be necessary. Regular inspections are essential