Once you’ve identified and installed the best flexible hose for your gas or cryogenic application, you can’t just set it and forget it. Just like the rest of the components of your system, regular inspection and maintenance is important for getting the most longevity out of your system.
In parts 1 and 2 of this series, we talked about understanding the terminology around flexible hoses and what questions to ask when looking at options, and then walked through choosing the right hose for the right application. In this post, we’ll cover some basic maintenance and troubleshooting tips to help keep your hoses in tip-top shape.
Remember, it’s always best to be proactive rather than reactive.
Establish a stringent visual inspection routine.
Whether it’s daily, weekly or monthly, the simplest place to start is by routinely conducting visual inspections so that you can spot any potential issues before they become more serious problems. Here’s what to look for:
- Discolorations: Any kind of spotting, freckling or marking is a sign of foreign matter coming into contact with the hose. In some situations, freckling can occur when using a leak-check solution, and this is not a problem. That said, be sure to always mix leak-check solutions according to the manufacturer’s recommended proportions so as not to damage the exterior braiding.
- Kinking: Kinks in the hose indicate too much physical stress or bending, and can compromise the hose’s overall integrity. When a fill manifold does not provide any support for the cylinder, it’s often the pigtail or hose that stops a cylinder from falling when bumped. This causes damage to the pigtail. Hoses with kinks or severe bends should be replaced.
- Braid Integrity: The stainless braid is what enables the hose’s inner core to withstand pressure. There should never be breaks anywhere on the braid. Even a single broken braid is cause for hose replacement.
- Fittings Status: Make sure threads are uniform, with no metal shavings or cross threads. If either are found, it’s time to replace the hose. A bad thread will leak under pressure. A thread gauge is a useful tool for checking that fittings are in good working order.
Follow up with a pressure test and leak check.
It’s extremely important to leak check all hoses and fittings while under pressure for any signs of leakage. A leak-check solution should be mixed to manufacturer’s recommended proportions, to avoid damaging the hose. Not all leak-check solutions work for every gas service, so check with your supplier to ensure you’re using the correct product.
A typical leak check is performed while the hose is connected to the fill manifold and under pressure. The best (and most expensive) gas to use for a leak check is helium, because its molecules are very small and will find leaks quickly. Other inert gases can be used in place of helium if budget necessitates, but steer clear of compressed air or other gases that could contain impurities.
Replace any old hoses nearing the end of their lifecycle.
While purchasing a high-quality hose is the first step in ensuring a long lifecycle, it remains true that hoses do not last forever. Hoses go through a lot of wear and tear in their daily usage.
High pressure hoses have set life expectancies based on the amount of service and the application. A good rule of thumb is that any hose that sees 18 cylinder changes per day, five days a week, will operate safely for approximately 18 months, assuming the hose has not been abused or damaged. At this rate, the hose will go through roughly 12,960 connections and disconnections.
Tube trailer hoses are often banged around and bent into a variety of ways, which shortens the lifecycle. In cryogenic applications, hoses are often pushed beyond the recommended velocity, which causes damage. Track the cycle rate of your current hoses, perform regular visual inspections and pressure tests, and replace any hoses that show signs of wear or are getting close to the end of their lifecycle.
Ratermann has the hose you need!
We have an exhaustive line of flexible hoses in-stock and ready to ship for any application. Use our hose builder tool to create a custom hose for your application or fill out the form below to get help choosing the right hose.