EXHIBIT 99.4 Certification Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (Subsections (a) and (b) of Section 1350, Chapter 63 of Title 18, United States Code) Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 (Subsections (a) and (b) of Section 1350, Chapter 63 of Title 18, United States Code), I, Jerry M. Brooks, Chief Financial Officer of Dril-Quip, Inc., a Delaware corporation (the "Company"), hereby certify that: (1) the Company's Quarterly Report on Form 10-Q for the quarter ended September 30, 2002 (the "Report") fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and (2) information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company. Dated: November 13, 2002 /s/ Jerry M. Brooks ------------------------- Name: Jerry M. Brooks Chief Financial Officer 1