Joining Method Solvent Weld
Solvent welding, also known as solvent cementing or solvent bonding, is the process of joining articles made of thermoplastic resins by applying a solvent capable of softening the surfaces to be joined, and pressing the softened surfaces together. Pipe and fittings are bonded together by means of chemical fusion. Solvents contained in primer and cement soften and dissolve the surfaces to be joined. Once the pipe and fitting are assembled, a chemical weld occurs. This weld strengthens over time as the solvents evaporate.
ABS, CPVC, and PVC plastic pipes are primarily joined by solvent cementing, though mechanical joints are also available. PE, and PEX pipe cannot be joined with solvent cements.
Solvent cement joining always involves a pipe or tube end and fitting socket or pipe bell. The inside of the socket is slightly tapered, from a diameter slightly larger than the pipe OD at the entry, to a dimension at the base of the socket that is a few thousandths of an inch smaller than the pipe OD. Thus, the pipe-to-socket match-up results in an interference fit more-or-less midway in the socket.
Solvent cement is applied to the outside of the pipe end and the inside of the socket. The pipe is then pushed into the socket until it bottoms. Some codes require a primer to be applied before the solvent cement.
When joining pipe and fittings with solvent cement, always:
- Cut the pipe ends square.
- Bevel and deburr the pipe ends with a chamfering tool. Use the proper primer and solvent cement and follow manufacturer's application instructions.
- Use the proper size applicator for the pipe being joined.
- Rotate the pipe 1/4 turn when bottoming pipe in fitting socket.
- Avoid puddling of primer or cement in fittings and pipe.
Relevant Materials And Systems