By Blissom · Updated 2026-10-23
Layout values: check them against your own bender, on scrap first.
Tools
- An identified PVC heater: an electric hot box, a heating blanket or a hot-air bending system rated for the conduit size and schedule you are bending. They are designed for controlled, even heat, but overheating or poor positioning can still scorch the conduit; follow the equipment's instructions for supported sizes, bend angles and cooling.
- Gloves for handling hot conduit.
- A bending form or template at the radius you want, or a chalk layout on the floor.
- Bending plugs for the larger sizes, as the PVC or equipment maker specifies; leave them in until the conduit has cooled.
- A wet rag or water to cool and set the bend.
Safety first: work in a well-ventilated area, since heated PVC can release harmful fumes, especially if overheated. Wear heat-resistant gloves and never use an open flame. Keep the heater on a stable, dry surface away from flammable materials, never expose energized heating equipment to water or rain, cool the conduit with a wet rag only after it is out of the heater, and never leave a powered heater unattended.
Heating PVC correctly
- Mark the bend: where it starts and how long it is. For a circular 90 the theoretical bend arc is π × R ÷ 2; heater instructions often call for a longer heated section than the arc, so use the heater maker's figure and check the radius on scrap.
- Heat evenly: with a roller-type hot box, rotate the conduit as the heater maker directs. With a heating blanket, wrap and position it as its instructions say, and do not rotate the conduit inside it. Uneven heat can flatten, kink or twist the bend.
- Test for limp: the section is ready when it sags under its own weight. Brown or blistered PVC is overheated; cut it off.
- Form and hold: bend over the form to the angle, keep the bend in one plane, and hold it until it cools. A wet rag sets it faster.
Bending a 90 in PVC
There is no take-up printed on a heater, so work from the radius. For a stub measured from the floor to the end:
Example: a 24" stub in 1" PVC on a 6" radius, the Table 2 minimum for this kind of bend (OD 1.315"): the bend starts 24 − (6 + 0.66) ≈ 17-5/16" from the end, and the theoretical bend arc beyond that point is about 9-7/16"; check the result on scrap. Many electricians use factory elbows for 90s and save field bending for offsets and kicks.
Offsets in PVC conduit
The geometry of a bend does not depend on the material, so the same starting layout applies: distance between offset bends = depth × multiplier (30° = 2), and the common 1/4" per inch of depth at 30° is a field shrink approximation, not an exact value. PVC heat bends have a finished radius and heated zone, so verify the first offset on scrap before repeating the marks. Heat each bend separately, make the first, let it set, then heat and make the second in the same plane. Use the offset calculator and the bending chart for the marks.
Minimum bend radius
| Trade size | Minimum radius (centerline) | PVC OD | Arc of a 90 |
|---|---|---|---|
| 1/2" | 4" | 0.840" | 6-5/16" |
| 3/4" | 5" | 1.050" | 7-7/8" |
| 1" | 6" | 1.315" | 9-7/16" |
| 1-1/4" | 8" | 1.660" | 12-9/16" |
| 1-1/2" | 10" | 1.900" | 15-11/16" |
| 2" | 12" | 2.375" | 18-7/8" |
Minimum radii per NEC Chapter 9, Table 2, "other bends" column, which applies to heat bends (the one-shot and full-shoe column is for bends made in a bender shoe). Larger radii pull easier.
Mistakes
- Using a torch. Open flame scorches the surface and weakens the wall.
- Heating one side. The bend kinks on the cold side or twists.
- Moving it before it cools. PVC creeps back while warm; hold the angle until it is set.
- Too tight a radius, which can flatten the pipe and effectively reduce its internal diameter, which the code does not allow.
- More than 360° of bends between pull points (352.24). Add a pull point.
Sources: NEC 2023: 352.24 (bends in PVC conduit) and Chapter 9, Table 2 (minimum bend radius); PVC conduit manufacturer bending instructions for heating equipment and plugging larger sizes. Method.
Questions electricians ask
Can you bend PVC conduit without a heater?
Some purpose-made tools allow cold bending of 1/2" and 3/4" Schedule 40 PVC under the conditions their maker specifies. Otherwise use identified PVC heating equipment or factory elbows. An ordinary heat gun used freehand can heat PVC unevenly or create hot spots, and an open flame scorches and weakens PVC.
How long do you heat PVC conduit to bend it?
Heating time depends on the conduit size, wall thickness, room conditions and heater, so follow the heater maker's instructions. When the section is uniformly pliable, take it out of the heater and form the bend.
Why plug the ends of PVC before bending?
On larger sizes (commonly 1-1/2" or 2" and up; check the PVC maker’s instructions), plugging both ends traps air that holds the pipe round while it is soft, so the bend does not flatten or kink.
Is a field bend in PVC allowed by the NEC?
Yes. NEC 352.24 allows field bends made with bending equipment identified for the purpose, as long as the conduit is not damaged and its internal diameter is not effectively reduced, with a radius not less than Chapter 9, Table 2.
The marks for any conduit
- Offsets, saddles and kicks with shrink, for PVC, EMT or rigid
- Developed length of every bend, so you know how much to heat
- Metric or inches, offline on site
- Saved jobs and PDF bend sheets
Android only. There is no iPhone version yet; the free calculators on this site work on any phone.
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