ug338 orgSpartan-6 FPGA Memory Controller User Guide (UG388) - UG388 ug388.pdf Document ID UG388 Release Date Revision 2.3 English Back to home pagePolypipe Underground Drain Riser Sealing Ring is desned to be used with the UG438 Side Riser. It provides a dry fix to seal the riser joint to the chamber base.