The commission shall appoint a director of the pipeline safety section of the Public Service Commission and such employees as may be necessary to carry out the provisions of this chapter, and shall fix their respective salaries or compensation. The commission may designate such employees as it deems necessary to take evidence at any hearing held or required by the provisions of this chapter, which employees are hereby empowered to administer oaths in all parts of this state so far as the exercise of such power is properly incidental to the performance of their duties in connection with the provisions of this chapter.