A resource on vertical tendons (and excellent resource for many other items as well) is the FHWA Post-tensioning Tendon Installation and Grouting Manual, May 2013, FHWA-NHI-13- 026. Sections 4.3.7 and 4.5.10 and 4.5-11 address vertical tendons. It can be downloaded here: https://www.fhwa.dot.gov/bridge/construction/pubs/hif13026.pdf.
One of the first considerations in a plan for vertical tendons is to ensure the particular grout to be used is rated for the vertical head/pressure that will be encountered. The pressure should be considered for the equipment as well. In addition, some strategies for grouting vertical tendons may include one or more of the following, especially for tall tendons: breaking the tendon grouting up into stages/lifts, grouting the top portion of the tendon as a separate operation, adding a reservoir/standpipe at the top of the tendon.