We purchased the Hot Bend PVC bender about 6 years ago. It uses a bbq tank to operate.
Been through the blankets and hot boxes. Blankets become worn out and we often get zapped from exposed coils. Boxes too expensive. You need electrical power to operate both of these and they take time to warm especially in the dead of winter.
The Hot Bend needs no power. It's portable and you even can bend pipe in a trench. We have multiple times.
We've use it to bend up 6" PVC, both water pipe and conduit.
It's actual original use is for shrink wrapping boats for winter. Someone figured out it can heat and bend PVC. We very rarely need fittings (90's) as we can bend our sweeps.
One of the best investments. Highly recommend it.
www.hotbend.com