This port adaptor enables a CamVac extractor with 4 inch diameter port to be reduced to 2.5 inches inlet, enabling connection to compatible CamVac accessories.
In seeking superior dust extraction machinery, we came across a small British company, Camvac, who were using their background in industrial vacuum cleaning systems to devise a new range of what can genuinely be called "Dust Extractors" at very reasonable prices. We purchased one of these units for our own workshop and, after more than 15 years of practical use, they are still our extraction system of choice.
The filtration provided by these units is achieved through three stages of filtration, achieving the removal of particles down to 0.5 microns. (Most of the older so-called "Dust Extractors" were incapable of removing particles below about 5 microns in size: it is the particles which fall into the 1 micron to 5 micron range that do most damage to human tissue and organs. Hence, in recirculating these particles, the older Chip Extractor-style of unit is actively failing to benefit the user's health). The first stage of the system is a large-area washable cloth filter, the second is a fine, easily replaceable paper filter and the final stage is a further cloth filter.
Part of the secret of the dust- AND chip-handling capability of these units is that the fan is located after the filtration stage and the extracted waste does not have to pass through the impeller before it reaches the collection sack. This arrangement also ensures that all of the dust-containing parts of the system are under vacuum the whole time so that there is no danger of leakage of particulates back into the workshop atmosphere. I also know from years of using a chip extractor that the systems which pass the waste through the impeller have an irritating habit of blocking all too frequently.
We can honestly say that in two decades of use we have only rarely experienced a blocked hose on the Camvac system - and we use it for "vacuuming" out the workshop floor with all of its shavings too!