The grades of 3 Gas Utilities stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

Piedmont Natural Gas Company, Inc. (PNY) boosts its rating from a B to a A this week. Piedmont Natural Gas Company, Inc. is an energy and services company that primarily transports, distributes, and sells natural gas. For more information, get Portfolio Grader’s complete analysis of PNY stock.

Northwest Natural Gas Company (NWN) shows solid improvement this week. The company’s rating rises from a C to a B. Northwest Natural Gas Company distributes natural gas to customers in western Oregon, as well as portions of Washington. The company also gets A’s in earnings growth and earnings surprise. For more information, get Portfolio Grader’s complete analysis of NWN stock.

New Jersey Resources Corporation (NJR) is seeing ratings go up from a C last week to a B this week. New Jersey Resources Corporation provides retail and wholesale energy services to customers in New Jersey and in states from the Gulf Coast to New England, and Canada. The company also gets A’s in operating margin growth. For more information, get Portfolio Grader’s complete analysis of NJR stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.