Williams (WMB -0.47%) has flown under the radar of many investors. It's not as big as some of its rivals in the energy midstream sector. It also doesn't offer quite as high a dividend yield as some of its more popular peers. However, Williams' 5.1%-yielding dividend is on a super safe foundation. Further, the company has a lot of fuel to grow its payout in the future. That's why income-focused investors won't want to overlook the pipeline stock.A financial fortressWilliams produces over $5 billion in cash f ...