How high up are the pipes? Euonymus fortunei is evergreen and self-clinging (like ivy) but not as vigourous. 'Silver Queen' and 'Emerald Gaiety' are excellent varieties for shady places

Consider that these pipes may need repair at some point.

You can buy a specific type of large mesh/fabric, on a roll, that you can losely attach to drainpipes - you can then grow a climber of your choice up that and if maintenance to the pipe is needed you just unclip the mesh/fabric and gently lower it down and then replace it when done.
All without damaging the plant that's attached.

The plants could be a thornless rose, clematis or ivy.

The 'fabric' contains the plant so it doesn't wander off the pipe and damage/attach itself to walls, roofs or drains.