Yelomine IB is the next generation in restrained joint pipe systems for HDD and the mining industry from CertainTeed. Yelomine IB is a PVC pressure piping system featuring an interlocking bell-shaped joint that eliminates the need for couplings. The 20-foot length product is available in 4-inch and 6-inch sizes at pressure ratings of 200 psi and 250 psi. CertainTeed Corp.