Issues with sealed gland fittings

Do not wrap it with PTFE tape; maintain the electrical continuity of the wire conduit. Whether water will enter the joint depends on the quality of the threads in that joint; generally, the threads of finished pipe joints are of good quality, so even if water does get in, it is only in small amounts. The threads produced on-site using a threading machine in tubes like these have very poor quality; it is difficult to ensure the sealing of the connections, and there is a high risk of water leakage.

The NPT thread is self-sealing and does not require tape. Other threads come with gaskets and do not require tape.

The electrical interface of the instrument. 　　If the tapered thread (NPT) already has the function of preventing liquid fuel leakage, it doesn’t really matter whether an additional sealing material is used or not ； 　　In the case of cylindrical threads, the diameter of the opening at the bottom of the connection is much smaller than that of the threaded hole; as long as the water entering through the threads does not exceed that threshold, it will not flow inside the gauge. As long as it doesn’t open upward, water won’t get in. 　　So it doesn’t matter whether waterproof additives are used for the joint. But just to be safe, it’s better to wrap some tape around it. 　　From an explosion-proof perspective, explosion-proof instruments do not require sealing; rather, they emphasize the presence of a venting gap (air permeability). Therefore, flexible pipe installation does not require sealing. On the contrary, flexible pipes always have joints equipped with metal gaskets that cannot be compressed into a tight seal; the design is such that air leakage will occur. 　　Actually, use a flexible tube to supply water. The vast majority are poured in from inside the wire conduit. Therefore, emphasis should be placed on the construction requirements. For example: the wire conduit cannot be led out from below the cable tray; the connection joint between the wire conduit and the flexible tube must be 100–200 mm lower than the connection joint between the instrument’s electrical interface and the flexible tube ； ………… 　

I’ve been too busy lately and haven’t logged in here; I’m sorry about that. Subsequent inspections revealed that the device interface is a 3/4\" connection, while the sealing joint is M25*1.5; it can be inferred that water entered at this connection point, entering through gaps of 3 mm between the teeth.

Using flexible pipes on-site can easily cause water to enter the instruments, leading to their damage

Threads that are tapered are not necessary; sealing is achieved through the threads themselves. For those without a taper, sealing accessories are required; it is recommended that the original poster learn about common thread types

The connector must not be wrapped with tape. To ensure electrical continuity, tape should not be applied at the gland and instrument threads.

I think there were some design requirements regarding this; for example, the wiring ducts shouldn’t be used to lead wires from a higher position to the instruments, but rather from below, in order to prevent water from entering. You can look up relevant information online. . . .

It’s not necessary; no connectors are required, as there are seals in place. To prevent water from entering, proper wiring is needed – by placing drainage at the lowest point of the cable conduit or the tray

Raw seal tapes do not meet explosion-proof requirements; use explosion-proof flanges instead. Flanges have an IP rating and contain sealing rings, and the thread size of the flange used must match that of the equipment when selecting it