so in this presentation we look at the skills required in order to put a 90-degree bend in a
piece of PVC conduit we've got two socket outlets screwed to the wall and we're gonna simply have a
piece of conduit that runs horizontally along here but the nice 90 degree bend and goes into
the other socket outlet and we look the skills required in order to put a nice smooth bend into
that PVC conduit little bit of a recap we're working with 20 millimeter PVC conduit they
also come 16 25 and 32 this time we're talking about the diameter of the actual conduit itself
so it isn't millimeters squared so we're using 20 millimeter PVC conduit and we have a lovely
smooth bend in it first of all we need to work out the length that we need to cut our conduit
at and for this we're going to be longer than we need it so when I take my tape measure I'm
gonna over hang the box and bring it round I'm gonna overhang the box this side and come out
to about a hundred and seventy centimetres or 1,700 millimetres so I'm longer this side and
longer that side than I need and then I'm gonna cut it back once I put my lovely smooth bend in
it let's cut the PVC conduit next so a required measurement of a hundred and seventy centimetres
or 1,700 millimetres going to need to cut the conduit now doesn't matter how we cut the end of
this stage because obviously it's longer than we need it we're going to end up cutting it back and
making sure that end is square and burr free in the future so the minutes just all about cutting
it to the required length so approximately for me 170 and we're gonna do this one over our knee
I don't want to see us doing is taking the conduit into the workshop using the square jaw vices in
order to hold it we do it over on me in this case using a junior hacksaw with not concern what the
end looks like at this stage we're obviously going to prepare the end when it's actually at
the required length what we need to do now is put the bend in the appropriate position within the
conduit itself so see how we're gonna do that so I'm ready to try and put my 90 degree bend
in my PVC conduit remembering that this and here is slightly shorter than this one here
so we will put the bend slightly more to one side than the other we're going to use a 20 mm conduit
bending spring the idea of bending spring is to prevent the conduit from collapsing when we bend
it equally you need a 16 25 or 32 depending on the size of conduit you're gonna use the spring
needs to be offered up on the outside first in order to work out the position in which you
want to start the bend so slightly more to this end for me than this end so this will be longer
going this way there's a cable on the outside preventing getting trapped inside the conduit I
just fold it over in order that I can drop it in to the conduit itself and position it down there
fold it over so I've got the spring here in this section of conduit what I would do next is warm
up the conduit to try and prevent that spring from rippling through I know over the years the conduit
isn't as good of grade as it used to be it does slightly whiten out the black when you put the
bend in we're gonna have to live without take a rag and we're gonna warm up the conduit in the
section we want to bend and that should be touch warm which it is and then for my technique only
under what I call a large motor bikes and my arms are at that kind of width will be playing
around with the width of the arms depending on the student so mine's about there okay and then
from that position I'm just going to fold it in hold it allow it to come out fold it in and hold
it and we go out finally again just hold it in I want to leave in a slightly over bent positions
I want to rest it beyond 90 in that position possibly about there the spring needs to come
out of this stage and need to be rested need to give a couple of minutes before we even consider
trying to cut it to the required dimensions so spring comes out and we're gonna rest that in
a over bent position for a few minutes before we do anything else with it so a rest up PVC conduit
and we can see our bend now it is approximately at 90 degrees we can just tug it out if we need
to but we can never put more bend in if so if it's gone beyond 90 or we can't do a show on this one
what we can't do is actually put more bend in without putting the spring back in because if
we do just collapses so we should have reinserted the bending spring for me to add more bend to the
90 degrees we can pull it out so we can't just gently tease it out but we can't put any more in
my cross-reference point is a steel conduit bend which is done on a conduit bending machine in the
former as whether that is an acceptable bending radius the bending radius should be two and a
half times the diameter of the pipe as a minimum which is a 50 mil radius however if I offer it up
here across the top of the steel conduit we can see that that's near perfect with the technique
we've used to get a bending radius identical to that one in steel so steel is done using the
former we used our big motorbike technique and we've got a bending radius very similar to that
we're gonna see how now we can adapt it in order to fit it between our two boxes so I'm ready to
cut my conduit in order to facilitate between the two boxes we need to put in some female adapters
so we need to unscrew these and put those in the boxes care must be taken that they don't
go all the way and the conduct will not go all the way in it stops it's a case of working out
how far it will go into your adapter because you won't become the conduit flush with either box it
will be shorter in both cases we need to allow for that when we make a cut so adapters are in
and what I do with this section here is I slides and saddles on the back we know afterwards are
going to go on in a different technique but at this stage this is not obviously how we
fit saddles but we know that from the workshop I'm going to slide these on there's a little
cross-reference for me so I can get it running horizontal with a wall so off of these over the
top with a couple of temporary saddles on for lengths and then I've got to work out where I'm
going to cut my pipe at each end remembering it will not go fully into the adapter will be
slightly short fully in and that's something we've got work out yourself and we're going to
have to make sure the ends are correct at that stage so offering that one round I'm going to
make my cut this end and I'll do the same this end I'm now ready to cut the conduit square and
deburr the end so let's see that first I'll do one in for you so over me again taking my joiner
hacksaw care now to try and get it as square as possible so I cut my conduit down believe you
or not in college we're gonna do this we're gonna square the ends squeeze using a file
super square and ream them out so there's none of those plastic little whiskers in there so we're
gonna clean it up okay so we've got a nice clean and nice and square nice and clean for college the
order that we can push it into the female adapter of both ends I'll cut the other one and then we'll
see what it looks like on the wall so I've made the necessary adjustments in my conduit that it
fits snuggly with him both adapters and doesn't move backwards and forwards when I'm pushing
against it so don't miss sliding in and out it's run horizontally so it looks good we've now only
got to secure it using the appropriate saddles as we move towards the 18th addition we're going to
find that the saddles are likely to be metallic because we do not want the conduit system to
collapse in the event of a fire or at least be held into position for the longest possible time
currently we're going to be fitting PVC saddles but then as we move forward we're going to find
that these are either going to be black metallic as they adapt them or we'll be using a steel
conduit saddle in order to support the conduit system itself BS seven six seven one says that the
saddle should be positioned within 300 mm of the box so from this socket coming out we must have
a saddle within 300 mm likewise where there's a bend in the conduit we must also support it
within 300 mil I believe our saddles are probably approximately here this side of the bend and
equal distance this side of em so it looks nice in order to support the conduit system so we've used
a technique to put a nice smooth 90 degree bend in it and we've made a few adjusting cuts squared the