EXHIBIT 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in Registration Statement Nos. 33-82396, 33-82398, 333-23697, 333-24475, 333-71044, 333-113426, and Post-Effective Amendment No. 1 to 333-113426 on Form S-8 of our reports dated June 2, 2009, relating to the consolidated financial statements (which report expresses an unqualified opinion and includes an explanatory paragraph concerning the adoption of the measurement date provisions of FASB Statement No. 158, Employers’ Accounting for Defined Benefit Pension and Other Postretirement Plans, as of April 1, 2008) and financial statement schedule of Graham Corporation and subsidiary, and the effectiveness of Graham Corporation’s internal control over financial reporting, appearing in the Annual Report on Form 10-K of Graham Corporation for the year ended March 31, 2009.

/s/ Deloitte & Touche LLP

Deloitte & Touche LLP

Rochester, New York

June 2, 2009