How do you fix a dog leg in conduit?

Put the second bend back in the bender where it was pulled, hold the straight part still, and twist the leaning leg back toward the plane of the first bend while easing a little pressure onto the handle. Work in small moves and lay it on the floor between each. A small dog leg comes out this way; a big one, or one on a short leg you cannot get a grip on, usually does not.

What causes a dog leg in conduit?

The pipe rolled in the shoe between the two bends of an offset or saddle, so the second bend was pulled a few degrees out of the plane of the first. It also happens when the pipe creeps round as you pull, or when you line the second bend up by eye instead of by a line along the pipe.

Can you fix kinked EMT?

No. A kink is a fold in the wall: the inside of the bend has creased and the bore is smaller there. Bending it back leaves the crease and weakens the wall further. Cut the kinked bend out and bend a new one, or use a new stick.

How do you straighten an over-bent 90?

Open it a little at a time: lay the pipe down with the stub up, keep the run held flat, and pull the stub leg back with the bender hooked over it for leverage. Go a degree or two at a time and check with a level; it springs back part of each move. If it is more than a few degrees over, it is usually quicker and better to bend a new one.

Will an inspector fail a dog leg?

A slight dog leg that still straps flat is usually a workmanship matter rather than a failure. A kinked or flattened bend is different, because it reduces the inside of the raceway and makes the pull harder. Your code book and your inspector decide; the safest standard is a bend that looks like it came out of the shoe.

Corriger les baïonnettes et les plis

A dog leg in conduit is a bend pulled out of the plane of the one before it, so the pipe rocks on the floor and will not strap flat. You fix a small one by putting the second bend back in the bender, holding the rest of the pipe still, and twisting the leaning leg back into plane a little at a time. Over-bent and under-bent angles can usually be worked back too. Kinks, flattened walls, crushed ends and corkscrews cannot: they are cut out.

What a dog leg is

Every bend in an offset, saddle or kick has to lie in one plane. If the pipe rolls a few degrees in the shoe between bends, or creeps round during the pull, the second bend goes off at an angle to the first: the rise is right, but the far leg points off to the side. On a 10' 0" (3.05 m) stick a few degrees of roll can put the far end inches off the line you meant.

How to spot one

Lay the first leg flat. A true offset lies still; a dog leg rocks, or its far end stands off the line.

Lay it on the floor. An offset on its side should lie on both legs without rocking. Push the near leg down; if the far one lifts, it is dog-legged.
Sight it. Hold the pipe up at the end and look along it. Both bends should sit on one straight line through the pipe, like a single stripe.
Check the pencil line. If you drew a line along the top before bending, it should still read as one straight line through both bends. Where it bends off, that is the bend that rolled.
Hold it to the wall. A leg that stands off the surface pulls the strap crooked.

Twisting a dog leg out

Find the bend that rolled. Lay the pipe on the floor with the first bend flat and sight down it. The bend whose leg leans off to the side is the one to work on — usually the second bend of an offset.
Put it back in the bender. Seat that bend back in the shoe exactly where it was pulled, arrow on its mark, hook on the pipe, the same way it sat for the bend.
Hold the rest still. Foot on the pedal to keep the shoe seated, the straight part of the pipe held flat so only the leaning leg can move.
Twist, a little at a time. Twist the leaning leg back toward plane by hand, or with a short length of larger conduit slipped over it as a lever, while easing a touch more pressure onto the handle. Small moves; the pipe springs back part of each one.
Check again. Take it out and lay it on the floor. Repeat until both legs sit flat, then check the rise has not grown from the extra pressure.

Keep your hands out of the gap between pipe and bender, and your face out of line with a lever that could slip. Twist steadily, never with a jerk or your body weight, and get a lever pipe fully over the leg so it cannot pop off. If the bend starts to ripple or flatten, stop: you are now making a kink.

It will not twist out when the dog leg is many degrees, the leg is too short to grip, the bends are too close for the shoe to seat one alone, or the bend has already been worked back and forth. Save the straight pieces for short runs and bend a new one.

Over-bent and under-bent

An over-bent 90

What you see: the stub leans back past plumb against a level.

Why: too much allowance for springback, or reading the degree line from above.

Fix: lay the pipe down with the stub up and the run held flat under your foot. Hook the bender over the stub leg near its top, handle out, and pull the leg back toward plumb — a degree or two at a time, checking with the level. A few degrees comes out fine; much more leaves the bend ovalled, and a new one is quicker.

An under-bent bend

What you see: a 90 short of plumb, or an offset with less rise than you laid out.

Why: not enough springback allowance; the pipe relaxed off the line.

Fix: the easiest fix of all. Put the bend back in the shoe so the pipe seats in the groove along the curve it already has, and pull a little more. On an offset, take the short bend to match the other, not both further.

Offset rise too big

What you see: the jog overshoots its target.

Why: both bends pulled past the angle, or the marks too far apart.

Fix: open both bends by the same amount the same way as an over-bent 90, or cut and rebend. Opening only one makes the far leg climb.

What cannot be fixed

Kinks and flattened walls

What you see: a crease or ripple on the inside of the bend, a flat on the outside, the pipe oval across the bend.

Why: the pipe lifted out of the groove because the pull came from the handle without weight on the pedal; or the pipe was too big for the bender.

Fix: none. Cut the bend out. A kink shrinks the bore, so the wire drags and can scrape its insulation on the pull, and it is exactly what an inspector sights for — see what an inspector looks for.

Crushed ends

What you see: an end that is out of round and will not take a connector or coupling.

Why: stepped on, driven over, or clamped too hard in a vise.

Fix: cut back past the damage, ream the new end, and account for the lost length in your marks.

Corkscrew

What you see: a run of bends that spirals: each one a little out of plane from the last, the far end nowhere near where it should be.

Why: a small roll repeated at every bend — typical on segmented sweeps and long runs of saddles.

Fix: none worth the time; twisting one bend puts the next out. Cut it and rebend with a line along the pipe.

Stopping it next time

A pencil line along the top before the first bend, and it faces the same way at every pull.
Sight after every bend, not only at the end. One rolled bend is fixable; three are not.
Foot on the pedal first, then pull, one steady motion. That is the whole cure for kinks; the hand bender guide has the stance.
The same springback on every bend, so no bend needs working back later.
Carry pipe, do not drop it, and keep it out of traffic.

The rest of the list — layout, reading the bender, and the pull — is on common mistakes, and the offset done right the first time is on how to bend an offset.

Questions

How do you fix a dog leg in conduit?: Put the second bend back in the bender where it was pulled, hold the straight part still, and twist the leaning leg back toward the plane of the first bend while easing a little pressure onto the handle. Work in small moves and lay it on the floor between each. A small dog leg comes out this way; a big one, or one on a short leg you cannot get a grip on, usually does not.
What causes a dog leg in conduit?: The pipe rolled in the shoe between the two bends of an offset or saddle, so the second bend was pulled a few degrees out of the plane of the first. It also happens when the pipe creeps round as you pull, or when you line the second bend up by eye instead of by a line along the pipe.
Can you fix kinked EMT?: No. A kink is a fold in the wall: the inside of the bend has creased and the bore is smaller there. Bending it back leaves the crease and weakens the wall further. Cut the kinked bend out and bend a new one, or use a new stick.
How do you straighten an over-bent 90?: Open it a little at a time: lay the pipe down with the stub up, keep the run held flat, and pull the stub leg back with the bender hooked over it for leverage. Go a degree or two at a time and check with a level; it springs back part of each move. If it is more than a few degrees over, it is usually quicker and better to bend a new one.
Will an inspector fail a dog leg?: A slight dog leg that still straps flat is usually a workmanship matter rather than a failure. A kinked or flattened bend is different, because it reduces the inside of the raceway and makes the pull harder. Your code book and your inspector decide; the safest standard is a bend that looks like it came out of the shoe.