You might need a metal hose if:
- If the temperature of the chemical being transported is extremely hot or extremely cold metal hoses can provide greater efficacy than rubber hoses in many instances.
- If the outside or inside of the hose will be exposed to highly corrosive chemicals metal hose can often offer superior chemical resistance.
- If the gases emitting from a chemical hose transfer cannot permeate through the hose wall you may need a metal hose. Many non-metal hoses are susceptible to gas permeation.
- If your application could cause heavy abrasion and overbending metal hose may provide the unique resiliency and flexibility to withstand that use.
- If avoiding a dramatic instance of transfer failure is a primary goal, metal hose should be considered. When metal hose fails it often develops small holes or cracks rather than breaking or failing completely.
- If your industrial application requires flame retardant hose you should consider a metal hose option. Metal hose can maintain integrity up to 1,300 degrees F
- If you must avoid hose collapse during full vacuum at all stages of your chemical transfer application you should consider a metal hose as it will maintain its shape in full vacuum when others may collapse.
- If you need a high level of flexibility in fitting configuration a metal hose should be considered as it can accommodate almost any fitting types while rubber hoses usually require standard fittings.
- If you know you need a metal hose assembly, we’ll help you find the answers to the below questions to build the right one for your use.
- Metal Hose (Type, Alloy, Size)
- Fittings for each end
- Length of the assembly (either overall length or live length)
- Fabrication options
When selecting a hose, you must consider three variables: pressure carrying capability, flexibility, and chemical compatibility.
Pressure Carrying Capability – The hose must be strong enough to handle the pressures to which it will be exposed. To determine hose pressure capability, refer to the “Maximum Working Pressure” stated for the hose. The Maximum Working Pressure must be reduced for each of the following circumstances:
Temperature – As temperature increases, hose working pressure decreases. After you have determined the proper alloy (see “Chemical Compatibility” below) go to the “Temperature Derating” table and match the alloy of the hose and braid with the highest temperature to which they will be exposed (either internally or externally) to obtain the proper derating factors. Then multiply the hose’s Maximum Working Pressure by the most limiting temperature derating factor.
Dynamic Pressure – Pulsating, surge, or shock pressures, like those encountered with quick opening or closing valves, can inflict severe damage on a hose. If your application entails pulsating pressures, the working pressure should be derated by 1/2. If your application entails shock pressures, derate the stated working pressure to 1/6 of its value.
Flexibility – Confirm that the hose’s minimum bend radius is less than the bend radius required for the application. Increasing the installed radius of the hose will reduce fatigue on the corrugations, increasing assembly life. Care should also be taken for applications with vibration. Contact Hose Master’s Inside Sales Department if excessive vibration is present. Refer to the Vibration chart on page 35 for additional information.
Chemical Compatibility – You must choose a material for the hose and braid that is compatible with the media being conveyed through the hose as well as the environment in which the hose is installed. When determining chemical compatibility, it is important to know the temperature and concentration of the chemical(s). Although there are many resources to confirm chemical compatibility, two of the industry standards that you may use are the National Association of Corrosion Engineers (NACE) and the Compass Corrosion Guides.