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<div>In a pipe grid, the 90 degree clamps only normally hold loads that are side loads from when people are up there moving things around, when the building vibrates, and during collapse scenarios. So they don't actually need to be super high rated. </div><div><br></div><div>The things that carry the vertical load are the threaded rods and the fittings on each end of the rods. if your pipes are secured to the wall, those might also be a load path. </div><div><br></div><div>I Am not a structural engineer or a lawyer, so don't claim me to be an authority.</div><div><br></div><div>Dale</div><div><br></div><div><br></div><div id="composer_signature"><div style="font-size:88%;color:#364f67" dir="auto">Sent from my Verizon 4G LTE smartphone</div></div><br><br>-------- Original message --------<br>From: Richard John Archer via Stagecraft <stagecraft@theatrical.net> <br>Date: 10/9/17 11:56 (GMT-05:00) <br>To: Stagecraft Mailing List <stagecraft@theatrical.net> <br>Cc: Richard John Archer <rja10@cornell.edu> <br>Subject: [SML] pipe grid question <br><br><br>University engineers are looking at the pipe grids in our spaces (not yet in the proscenium) . Seems like an odd time after 30 years in the building ….but…<br><br>Grids are all kind of typical looking …..two way #40 1 1/2” pipe grid , cross grid connectors (so one direction of pipe below the other direction) , a bit over 4’ x 4’ spacing….beam clamps with 1/2” threaded rod seemingly spaced appropriately The problem is with the pipe clamps….most appear to be JP Clancy half pipe clamps (or other manufacturer? Clancy did Proscenium rigging). Half pipe clamps only have a 200 # RWL . Why would anyone install these in a grid? ….they just adequately hold up the pipe weight. Am I missing something here? Was this some Cornell value engineering at it’s finest? I’m sure original theatre consultants wouldn’t have spec’ed this (ARTEC) <br><br>Needless to say, we’ve been hanging up to maybe 200 fixtures in there for years. Biggest flexible space is about 50 x 50. <br><br><br><br>DickA<br>TD, Cornell U <br>____________________________________________________________<br>For list information see <http://stagecraft.theprices.net/><br>Stagecraft mailing list<br>Stagecraft@theatrical.net<br>http://theatrical.net/mailman/listinfo/stagecraft_theatrical.net</body></html>