A PVC threader is a tool designed to cut threads into the surface of heavy-grade PVC pipes. The threaded sections are then used to facilitate joining lengths of pipe or attaching accessories. PVC threaders may be manually operated or motor driven with varying levels of automation. In both cases, the PVC threader consists of a rotating head equipped with a set of four removable cutting inserts. This feature allows the quick and easy changing of thread pitch and profile without the need to change heads.
PVC pipe is an immensely convenient and popular construction element commonly used in a wide variety of domestic and industrial applications. In most cases with smaller, low pressure installations, it is possible to join PVC pipe or add accessories such as valves, T-pieces, and blanking fittings using a suitable PVC cement only. In the case of larger systems carrying higher pressures, these operations are often facilitated by threading the pipe to accept screw-on fittings. This is generally only done on grade 80 or above pipes as they feature wall thicknesses suitable for thread cutting. These threads are cut into the ends of the pipe using various types of PVC threader.
Depending on the size of the pipe and the location of the project, pipes may be threaded using one of two types of PVC threader, the first being a manual tool closely resembling a conventional steel threading die. These tools consist of a universal cutting head into which a set of four cutting inserts are fitted. The cutting head is hollow at its center allowing it to pass over the pipe and fit into a handle which affords enough leverage to ensure low-effort turning of the cutter. The cutting inserts slide in channels in the head with their cutting edges towards the center and consequently against the pipe surface. The inserts may be adjusted in and out in their channels, allowing a single head to be used to cut a variety of pipe diameters.
To cut a thread, the PVC threader cutting head is adjusted to suit the particular pipe diameter, inserted over the end of the pipe, and turned in a clockwise direction while maintaining constant forward pressure. This cuts the thread while advancing the cutter up the length of the pipe. The threader is generally turned until the pipe end exits from the back of the cutter head, at which point it may be turned anti-clockwise to remove it from the pipe.
The second type of PVC threader is a motor-driven tool that is usually permanently mounted in a workshop or on the back of a service vehicle. These tools work in the same way as a manual cutter and use the same type of cutter head and inserts. The cutting head is, however, driven by an electric motor allowing for the threading of larger pipes. These machines often feature sophisticated automated control systems that allow for hands-off operation and very precise cutting. A large range of cutting insert sets are available for both tool types, allowing for rapid and easy thread profile or pitch changes to be made.