Then you need a hold-down support.

See some examples.


http://www.pipingtech.com/products/ptpcat/pipeshoes/nofw/fig1100.htm

http://www.pipingtech.com/products/ptpcat/support/holddown/index.html


or from Lisega, see lift-off restraints inside this catalog.
http://www.lisega.com/pdf/pg4_us.pdf

Regards,
_________________________
Dan