Mastic Tape, Rubber Mastic Tape. Butyl Mastic Tape System Description:N-99 ( Mastic Tape ) Series are complementary goods,and it is filling of the weld bead. N-99 series have capability to smooth the surface of the pipe. Moreover, it can be applied by hand. Product Advantages: Heavy duty adhesive. Conformable to irregular shapes. Release Liner. Established in ground history. Complies with AWWA (American Water Works Association) C-214 standard Compatible with general coating systems. N-99 Mastic Tape, Rubber Mastic Tape. Butyl Mastic Tape series Coating Systems with AWWA C-214 Standard: