Apparatuses for controlling fluid flow are important components for delivering process fluids for semiconductor fabrication. These apparatuses for controlling fluid flow require a variety of fluid flow components which are tightly packaged within the apparatuses for controlling flow. Servicing the apparatuses requires specialized equipment and methods which enable installation of seals in close quarters in apparatuses which are installed in the field. Seal insertion tools may be used to facilitate installation of the seals to permit efficient assembly of fluid flow components into apparatus for controlling flow.