The other type of flow within a conduit is pipe flow. Not all flow within a closed conduit is considered pipe flow. There may be integral reinforcement within the conduit wall. Steel framework can be easily constructed of electrical conduit. Electrical codes may restrict the length of a run of some types of flexible conduit. Most of the various fittings made for metal conduit are also available in PVC form. The thread is used to join pieces of electrical conduit and cable glands. Couplings connect two pieces of conduit together. They have little flexibility and behave more like rigid conduit rather than flexible cables. Thus, language is viewed as a "conduit" conveying mental content between people. The gases vesiculate and accumulate as they rise through the magma conduit. However, an exchange took place between the two countries using Turkey as a communication conduit. The concrete used for conduit linings was usually waterproof. There is an overhead associated with the creation of any conduit. The male urethra is the conduit for semen during sexual intercourse.