Installation:

1) Cut main pipe to facilitate boss junction

All that is required is to make 2 cuts parallel to the center line of the pipe that are equal to the width of the small internal diameter of the oval branch line. The length of the cuts is equal to the large internal diameter of the branch line.  These cuts can be done with a angle grinder, a plasma cutter, a gammer saw etc. 

2) Remove the excess material

The small piece of pipe can be knocked out with a small hammer, if it is required that the scrap pipe does not drop down the main line a hole can be drilled into it and a piece wire used to hook it out before knocking the scrap out. 

3) Attatch the Boss junction to the main line

Ferro compound is used to glue the Cast Iron Branch connector onto the main line. The Ferro compound is a 2 part epoxy that curers under water  A layer about 2mm thick is all that is required after gluing the Boss Junction is strapped on to the main pipe with 2 stainless steel worm drive clips ( radiator hose clips ). 

4) Smoothing the compound

The inside of the Boss Junction & the main pipe should be smoothed so that there are no snags to cause blockages. The Ferro compound can be effectively smoothed using rubber gloves dipped in water

5) Curing

Leave the ferro to cure it will take 8 to 24 hours. The new branch line can be connected straight away as the worm drive clips will hold the boss junction in place while the ferro cures, however it is best to let the Ferro to cure first.