Ratermann Manufacturing, Inc. Customer Service 1-800-264-7793 y Fax 1-800-264-7797 y Order Online at Web Store www.rmiorder.com 20A-26 MAINTAINING YOUR HOSE As a major manufacturer of hoses used in the Industrial, Medical and Specialty Gas industry, we highly recommend that you implement an ongoing inspection program for all compressed gas and cryogenic hoses. Remember, it is better to be “Proactive vs. Reactive.” The goal is to replace the hose before it fails.“ We care about this market, however, in the past two years we have witnessed “first hand“ the negative effects of misused and abused hoses. In the interest of time, we will limit this discussion to PTFE, ETFE, and “all metal“ hoses only. We have purposefully left out oxy-fuel hoses. The following recommendations utilize some common safety practices. First of all, please understand that not all hoses are constructed in the same manner. Added to that, compressed gas and cryogenic hoses are used in many different ways. It is impor- tant that you identify and address your critical applications first. Critical applications will vary in each facility, however, a common guide would be as follows: high pressure fill manifolds, tube trailer transfill systems, and cryogenic transfer. There are a few basic “maintenance“ steps that you can implement rather easily. In fact, a continual hose maintenance program will go a long ways towards increasing the life of this important tool, while preventing the chance of serious injury or damage. How do you begin your maintenance program? Conduct a Visual lnspection Probably the most important thing that an operator can do (as part of a maintenance program) is a visual inspection. This should be conducted on a regular basis (daily, weekly, or monthly) depending on the application, and the usage/cycle rate. A continual visual inspection is the best way to identify and prevent a potential problem. What should you look for? • Discolorations Freckles, spotting, or other markings are an indication of a foreign matter coming in contact with the hose. Often, freckles can occur from the use of a “Ieak check“ solution. Typically, this is not a problem. However, it is crucial that leak check solutions be mixed to the manufacturer’s recommended proportions. If the proportions are not correct, braid damage can occur. With ethylene glycol (a common substance used in oxygen free leak check), the wrong propor- tions can negatively affect the stainless steel braid. • Kinking A kink in the hose is an indication of over bending, and/or over stressing. This type of move- ment can compromise the overall integrity of the hose. Some fill mani- folds provide no means of support for the cylinder. If the cylinder is bumped, quite often it is the pigtail or hose that stops the cylinder from hitting the ground. Unfortunately, this action will usually cause damage to the pigtail. If you find any kinks or severe bends, remove and replace the hose. • Braid Integrity The stainless braid gives the inner core of the hose the ability to withstand pressure. There should not be breaks anywhere on the stainless steel braid. A single broken braid is the sign of a potential problem. • Inspect the Fittings A simple visual inspection of the threads will tell you much. Look to see that the threads are uniform, you should not see any metal shavings or cross threads. If any of these characteristics are found, remove and replace the hose. A bad thread will typically leak under pressure. Thread gauges can be purchased to ensure that fittings are within speci- fication. Pressure Test & Leak Check Leak Check Hose It is very important to leak check the hose and fittings under pressure for any signs of leakage. Leak check solutions are commonly available and work very well under pressure. It is crucial that you not only use the correct solution, but that you mix the solution to the manufacturer recommended proportions. Failure to do so can cause damage. Keep in mind, not all leak check solutions work for every gas service. Check with your supplier to make certain you are using the correct “leak check” product. Pressure Test It is very important to leak check hoses on a regular basis. Often, this test is conducted while the hose is attached to the fill manifold and under pressure. The best gas to use for a leak check (and most expensive) is helium. Helium works well because the helium molecule is very small. As a result, helium will find a leak better than most other gases. Keep in mind that this can get a little spendy, so other inert gases can be substituted. We do not recommend compressed air or any other gas that could contain impurities. The braid on this hose was chemically attacked by an improper mixture of leak check solution. Thread checking tools are used to ensure fittings are in spec. For Leak Check Products see page 10A-21 Maintaining Your Hose
