I spent rather too much of my early career undertaking experimental tests on gas transport hoses in the offshore industry.
This is a safety-critical issue, since pumping natural gas onshore via these flexible hoses could result in disaster if the stainless steel liners were ever breached.
Here you can see that the welding together of the inner steel hose components has caused a tiny pinpoint of corrosion and then a small leak.
This was only detected after many hours surveying with an endoscope and methodical pressure testing of liner subsections.
