UNITED STATES SECURITIES AND EXCHANGE COMMISSION Form 10-K FOR THE FISCAL YEAR ENDED DECEMBER 31, 2019 Washington, D.C. 20549 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 ☑ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 OR Commission file number 1-13179 (Exact name of registrant as specified in its charter) New York (State or other jurisdiction of incorporation or organization) 5215 N. O'Connor Boulevard Suite 2300, Irving, Texas 31-0267900 (I.R.S. Employer Identification No.) 75039 (Zip Code) FLOWSERVE CORPORATION (972) 443-6500 (Registrant’s telephone number, including area code) (Address of principal executive offices) Securities registered pursuant to Section 12(b) of the Act: Trading Symbol Title of Each Class Name of Each Exchange on Which Registered FLS FLS22A New York Stock Exchange New York Stock Exchange Common Stock, $1.25 Par Value 1.25% Senior Notes due 2022 Securities registered pursuant to Section 12(g) of the Act: None Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes  ☑ No  ☐ Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes  ☐ No  ☑ Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes  ☑ No  ☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes  ☑ No  ☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer”, “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act. Large accelerated filer ☑ Emerging growth company  ☐ Accelerated filer  ☐ Non-accelerated filer  ☐ Smaller reporting company  ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or  revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes  ☐ No  ☑ The aggregate market value of the common stock held by non-affiliates of the registrant, computed by reference to the closing price of the registrant’s common stock as reported on June 28, 2019 (the last business day of the registrant’s most recently completed second fiscal quarter), was approximately $3,069,855,077. For purposes of the foregoing calculation only, all directors, executive officers and known 5% beneficial owners have been deemed affiliates. Number of the registrant’s common shares outstanding as of February 12, 2020 was 130,901,014. DOCUMENTS INCORPORATED BY REFERENCE Certain information contained in the definitive proxy statement for the registrant’s 2020 Annual Meeting of Shareholders scheduled to be held on May 21, 2020 is incorporated by reference into Part III hereof.