I'm assuming this is to insulate the pipes from freezing in the winter. If that's not correct, then let us know.

You should know a few things:

1. Insulating pipes, by itself, won't keep them from freezing

2. You need some source of heat. Insulation just slows the heat from dissipating to the surrounding (cold) air.

3. The heat needs to be reliable - the best is passive, from the interior or from the water itself.

So, the best type of insulation for pipes is generally foam sleeves. It's split so it goes on easily and has adhesive to hold the two parts together. Look for a stated R factor - the higher the R factor the better the insulation. If you are installing it yourself (an easy job) use a hand miter box to cut the foam to get a nice tight joint if you can't use a factory edge. Also use miter box for 90 degree elbows.

Get the foam that's the proper size for your pipe - you don't want it to not close around the pipe, or to have a bunch of free airspace.

if it will get very cold, and there's no heat from the room - you may need heat tape. Heat tape can fail though - it can come unplugged, etc. Try to do it so that you aren't relying on heat tape.

@Jake The Wonderdog . I am just looking to do if for condensation purposes.

Split foam is still the right answer - just no worries about heat.

I use a zip tie - not too tight - every so often to make sure it stays closed. Use a really good quality tape or silicone on foam joints if you are in an attic, for example, and condensation would stain the ceiling.

What @Jake The Wonderdog says. The split foam is readily available at Home Depot et. al., in stock in the usual residential sizes. I used it years ago in a particularly humid basement to eliminate the dripping condensation on the floor off the house's cold water pipes and it worked great.