The inlet for explosion-proof instruments is too small; the cable cannot fit in. What should be done?
Thread Content
At the scene, I often encounter situations like this; I don’t know how to handle them properly The thread size at the inlet of flameproof instruments (such as pressure transmitters) is M20x1.5. The outer diameter range of the inlet cables with flameproof fittings of M20x1.5 is 8–12 mm, whereas the outer diameter of the cables used in the field is 18 mm; therefore, flameproof fittings of M32x1.5 are required. My idea is to install an explosion-proof pipe fitting at the instrument inlet, change the thread specification of the inlet to M32x1.5, and then install an M32x1.5 explosion-proof gland. I’m not sure if this will work Is it compliant with the standards? Thank you!
Is the thread on the instrument itself M20*1.5? It should be possible to clamp it after making the connection, but the length of the transition section needs to meet the requirements. The outer coating must definitely be removed before it can fit into the M20 socket; otherwise, given its outer diameter, it won’t fit in. So it might be necessary to add an additional extension tube.
Why was such a thick cable used? Wasn’t this considered during the initial selection?
If I understand correctly, your problem is that the outer diameter of the cable is 18, but the entry port is too small to accommodate it. And from the perspective of your solution, you’ve just added a large adapter; it seems like this approach only provides a temporary fix rather than a permanent solution. The cable still can’t be inserted into the instrument, because the size of the instrument’s inlet remains unchanged. Visually, the only option for dealing with such a thick cable seems to be stripping it, that is, removing the outer protective and shielding layers.
The outer skin definitely has to be removed; my idea is to ensure good sealing inside the explosion-proof gland. I just don’t know if doing this will work Does it meet the standards?
Doing this is in line with the standards, right?
Indeed, the cable needs to be stripped in the entry section; my goal is to ensure sealing at the explosion-proof gland area, but I’m not sure whether this approach complies with the specifications
And aren’t pressure transmitters intrinsically safe?