Inspection/Testing of Conduit Seals (aka Seal-Offs)
Inspection/Testing of Conduit Seals (aka Seal-Offs)
(OP)
Earlier this year we had an incident where failed conduit seals allowed natural gas to seep from a classified location into an electrical panel in an unclassified area, which caused an explosion. The seals appear to have been improperly installed (bunched wires) and have all been replaced.
I'm writing a procedure for my company to implement a new policy for 100% visual inspection of conduit seals to ensure wires are properly separated and the seals properly poured to minimize the chance of this happening again.
I know that conduit seals are not perfect, but I'd like to include a procedure to test seals to verify they are installed properly. One of our electrical engineers said we could use water and let it sit for a few minutes to see if there is significant leakage, but that usually they are just visually inspected. He said that the water could be removed with a paper towel and that the small amount of water that might seep through the seal is inconsequential.
My question for the forum is whether there is an established procedure for testing conduit seals using water (or similar) which I can refer to in my instructions. I understand from looking at other threads that helium detection and pressure tests are also options, but I would prefer something simple that requires minimal special equipment. OTOH, we need to do this properly if we're going to do it at all.
BTW, I'm not cutting out the EE; he's just really busy and doesn't have time to write this procedure so this is the fastest way to get it done. My intention is to finish the draft instructions and route it to our electrical engineer and other folks for review/comment.
I'm writing a procedure for my company to implement a new policy for 100% visual inspection of conduit seals to ensure wires are properly separated and the seals properly poured to minimize the chance of this happening again.
I know that conduit seals are not perfect, but I'd like to include a procedure to test seals to verify they are installed properly. One of our electrical engineers said we could use water and let it sit for a few minutes to see if there is significant leakage, but that usually they are just visually inspected. He said that the water could be removed with a paper towel and that the small amount of water that might seep through the seal is inconsequential.
My question for the forum is whether there is an established procedure for testing conduit seals using water (or similar) which I can refer to in my instructions. I understand from looking at other threads that helium detection and pressure tests are also options, but I would prefer something simple that requires minimal special equipment. OTOH, we need to do this properly if we're going to do it at all.
BTW, I'm not cutting out the EE; he's just really busy and doesn't have time to write this procedure so this is the fastest way to get it done. My intention is to finish the draft instructions and route it to our electrical engineer and other folks for review/comment.





RE: Inspection/Testing of Conduit Seals (aka Seal-Offs)
RE: Inspection/Testing of Conduit Seals (aka Seal-Offs)
RE: Inspection/Testing of Conduit Seals (aka Seal-Offs)
A lot of ultralight builders put schrader valves and small gauges into the aircraft frames then leave them pressurized with a few psi. This keeps the moisture out of the inside of the frames and instantly detects cracks.
Having wires running in and out does increase the complexity of this scheme tho.
RE: Inspection/Testing of Conduit Seals (aka Seal-Offs)
RE: Inspection/Testing of Conduit Seals (aka Seal-Offs)
RE: Inspection/Testing of Conduit Seals (aka Seal-Offs)