I have been using knee hi-s since about 82,when I worked for The
Butler Carpet Cleaners.Then we would just insert into tank elbow and rubber band it.Drawback was you had to insert your hand into the waste tank,and get some nasty drips on ya...lol
But we use a pool filter similar to Jim Martin's set up now.But the mesh filter in not utilized,we just insert over the outer end and cuff it so it only reaches to about 3-4 inches from the end...So when she fills she does not constrict airflow.
I like Jims, idea about drilling holes in the back of the filter,very professional images might I add...
But here we do use a filter,we have a hourly change for the knee hi-s.They are smaller to remove and restriction,I feel becomes minimal...
The ones
Butler used to sell were very heavy duty,but some what expensive about 3-5 dollars per,I think ?
So I became the only man alive who bought more panty hose then women...lol...
I believe it was the lack of a stronger knee hi that lead me to change them more often ???
I tried it with the
matrix defender filter when it was introduced around 86-90 ???
But the barrel was too wide about 1.5 feet or so,an it warped so it would not seal properly ...
It opened by 2 latches,originally came with a mesh filter bag but the slots to line it up were to shallow.An many times you would open it to find the mesh bag anywhere else.But were it was meant to sit ???
But for a higher cfm machine properly built it might have been very sweet...imagine a barrel cut length wise that clamped back together...A 2 inch barb on each side.It also lacked a arrow feature,so you could quite easily reverse it with out knowing .So it as other non roadtest items phased out of the catalogs...
With a little better field testing ,It might have made the big leagues.But it was introduced around the same time as the pool version.The rest is history...