Every person heretofore, now or hereafter employed by cities of the second class A as herein provided, if any, of the age of fifty-five years and upwards, who shall have been so employed for a period of fifteen years or more, and have contributed to the fund for twenty years or more, shall upon application to the board of pensions herein created be retired from service and shall during the remainder of his or her life receive the pension or compensation fixed by this act, subject to such qualifications as are herein contained.
53 P.S. § 30591