Methods and formulas for bending rigid pipe with Greenlee 555

[IndTS]

I decided to register because my search to master bending conduit always seems to lead here.

I work for one of the largest industrial Electrical and Instrumentation contractors in the south. Due to where I live, a large number of chemical plants and oil refineries are within a reasonable distance. As an employee you are transfered to one of the jobs currently going on.

Some jobs are maintenance oriented, a small group of guys work everyday in the plant. Tasks range from running conduit, pulling wire, grounding, cable tray, mcc work, terminating instruments/motors/lights/panels/junction boxes, etc. Some jobs are new construction jobs, generally these jobs can range from small (3-10 people) to very large (100-300 people). Here the tasks are the same, except for all the work being focused on building new plant units/facilities. Generally the job tasks remain the same.

Bidding jobs works in the usual fashion, some jobs are "hard money" (all new construction jobs ive been a part of). Here speed is a very large factor, work hard, work fast, managed material and so on. Generally at the end of the day, each worker has to turn in their production for the day. Then we have the "T&M" jobs where is pace is slower and less competitive.

All styles of workers work on these jobs, some are obsessed with being the fastest, best, etc. Some people carry alot of pride in their quality of work, matching bends/couplings/perfecting/beautifying. Others just want to get their job done easily and are not so critical of their craftsmanship. Each foreman/supervisor you work for has their own standards.

Anyhow, on to my original subject...

On all of our jobs we are supplied with a greenlee 555 for 3/4-2" and a larger greenlee bender if pipe bigger than 2" will be run. Personally, I like to strive to produce the highest quality work within my limits. When running multiple conduits I like to match my couplings and bend all size conduits in the shoe of the largest conduit in the run.


I'm just looking to learn and share information pertaining to bending conduit with the 555. I've found most of the free information out there and checked out the greenlee manual, which is mostly just a table of predetermined measurements and the numbers according. I'll post some of the basic methods and techniques i've learned in a little while.

 

[IndTS]

In my examples i'll use information from the bender i use on my job and each example will be in regards to 3/4 rigid.

Deduct = 9" Centerline Radius = 5 7/16

Back to Back 90's

20 inch stub, 20 inches back to back.

1. Using the deduct, make your mark for the first 90, load the pipe and bend it.
2. Lay pipe on table, measure from back of the 90, 20" then subtract the deduct.
3. Load pipe with first 90 in front of the bender shoe, bend pipe on new mark.

Bending second 90 by turning the pipe around

1. Using the deduct, make your mark for the first 90, load the pipe and bend it.
2. Measuring from the back of the 90, 20" then add your centerline radius of 5 7/16
3. Load pipe with first 90 behind bender shoe/rollers, bend pipe on new mark.
(It's been awhile since i've done this and I feel like i've left something out)

I'll post some more methods when I get home. Such as laying out pipes for racks to have matching bends/couplings without cutting each end. Some people think this is a waste of time, but I prefer this method because it not only looks better, its much faster.