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Explosion-proof flexible hoses are designed for flameproof instruments; many of their functions are unnecessary and cumbersome to use for intrinsically safe instruments or in applications that do not require explosion protection. A gland head, also known as a cable fixing head, is installed at the connection point between a cable and electrical equipment; it serves to introduce the cable, fix its position, provide sealing, and offer explosion protection. Generally, for intrinsically safe instruments, it is sufficient to have functions such as fixation, waterproofing, sealing, and intrinsic flame resistance. Engineering plastics can meet the requirements ； The gland fittings for flameproof instruments sometimes also need to have the function of creating a pressure relief channel and absorbing energy; gland fittings with such functions are usually made of metal. After the instrument wires are led out from the gland, leave a length of less than one meter in the space, and then pass them through tubes or into cable trays. The pipe entry points and the inlets of the cable trays should also be secured using gland fittings (other methods are also acceptable). For signal wires other than current, resistance, and digital signals, if they are not shielded wires, it is best not to use gland connectors (it is preferable to use shielded wires); caution should be exercised when using gland connectors for compensation wires. If an armored cable is used, only an armored cable sealing joint is required; no flexible tube is needed. The armored cable also enters the junction box through an armored cable sealing joint ； If it is a non-armored cable, use a cable sealing joint together with a flexible tube; the flexible tube is connected to the tee (for drainage), and the tee is connected to the conduit. The wire conduit passes through the flexible tube and then connects to the cable sealing joint of the junction box. The power inlet for the junction box is located at the bottom of the box, so generally no additional tee for drainage is needed. The cable sealing joint is a cable entry device; for explosion-proof instruments, its purpose is to work together with the instrument itself to achieve explosion protection. There are no explosion-proof requirements at the wire ducts; using cable sealing joints for waterproofing is somewhat overkill. Gland is an internationally standard cable entry device. There are other types of cable clamping joints in China as well. For example, Nanyang Explosion-Proof Motor Factory has always insisted on using its own outlet couplings, which are available in two types: flared and threaded. For electrical connections, they sometimes don’t use glands either, but rather use threaded ports with sealing rubber rings. Both of the above methods comply with the **explosion protection specifications.