Once investors start to look at dividend stocks with yields north of 4%, it's time to start considering whether that payout is sustainable or headed for a future cut. If you can find those reliable, high-yield dividend stocks, then you'll want to hang on to them for as long as possible.

If high-yield dividend stocks sound appealing to you, here are three companies you should consider: Total SA (NYSE:TOT), Brookfield Infrastructure Partners (NYSE:BIP), and National Grid (NYSE:NGG). Here's a brief look at what these companies do and why their yields of at least 4% look like great buys. 

Hundred dollar bills with a note that says "dividend" on top of them.

Image source: Getty Images.

Fast response to the changing market

Integrated oil companies are like massive ships in the ocean. They are too big to change direction on a dime, but their size allows them to handle tougher seas -- or, in this case, low oil and gas prices. During this most recent down cycle, though, Total was surprisingly nimble. Part of it was luck as many of its major projects were completed in 2015 and 2016, which allowed management to wind down spending quickly. At the same time, the company was adept at lowering its production costs to the point that last quarter's free cash flow generation was at the same 2013 levels, when oil was $100 a barrel.

Now that the market has stabilized around $50 a barrel, Total is taking advantage of the situation by making some big investments and acquisitions to boost production. It has won several billion in concession contracts in the Middle East that will provide low-cost production and stable returns for many years to come. It has also upped its investments in U.S. shale, liquefied natural gas export facilities, and petrochemical manufacturing.

Locking in these new projects today when oil service contracts are low should help boost profitability over the next several years, especially if management can meet its stated goal of more than 5% production growth per year until 2019. If you sprinkle in its investments in renewable power as a way to make another pivot many years down the road, Total looks like a fantastic investment in the oil and gas business that also happens to have a dividend yield of 6.25%. 

Simple business, steady dividends

Businesses with steady revenue streams and geographic competitive advantages are often described as "toll road-like." For those seeking high-yield investments, there is no better way to heap praise on the stock than to say it has toll-road qualities. Brookfield Infrastructure Partners takes this to the next level as a decent portion of its revenue comes from toll roads.

Brookfield Infrastructure owns a broad range of energy, utilities, transportation, and communications assets. Think things like electric and gas transmission, hydroelectric dams, ports, and those toll roads mentioned above. Not only are these critical infrastructure assets that are mostly regulated businesses, but they also have substantial barriers to entry such as high capital intensity and entail managing public-private partnerships with local governments. 

With these kinds of competitive advantages, Brookfield is a kind of business that almost runs itself. What's even better is that the company has an adept management team that consistently looks to deploy capital in the most efficient way. That's how the company is able to project long-term dividend growth in the range of 5% to 9% annually. Today, shares currently have a dividend yield of 4.3%, which makes it a pretty attractive stock.

Earnings stability from both sides of the pond

Like Brookfield Infrastructure Partners, National Grid is the kind of long-term, high-yield dividend stock you want to look for. A vast majority of its revenue comes from regulated businesses: electric transmission, natural gas transmission pipelines, and natural gas distribution pipelines in the U.S. and the U.K. In most of its U.K. markets, it's the only game in town.

National Grid's U.K. businesses aren't going to grow much. That market for electric and gas transmission is quite mature and there aren't many projects outside maintaining existing assets. Also, since National Grid only gets to renegotiate new rates at fixed intervals, there are fewer incentives to invest. What its U.K. business does provide, though, is a massive cash cow that supports its generous yield of 4.1% as well as provides funding for investments in the U.S.

National Grid will dedicate more than 50% of its $4 billion capital plan for the upcoming fiscal year toward its U.S. regulated utility business. National Grid can petition for a rate hike each time it determines it needs one. That worked out last quarter when it received rate hikes for two of its New York operations. On top of its stable business, management just announced it had closed a deal to sell a majority stake in its U.K. gas distribution business for 13.8 billion British pounds. The proceeds will be given as a special dividend to investors. 

National Grid is by no means a dividend growth stock, but its business is suited to stable payouts that will modestly rise over time. At its current dividend yield, there is a lot to like about National Grid's stock. 

Tyler Crowe owns shares of Total. The Motley Fool owns shares of and recommends National Grid. The Motley Fool recommends Brookfield Infrastructure Partners and Total. The Motley Fool has a disclosure policy.