Chemical plants and refineries are some of the largest users of metal hoses, however, these often demanding environments pose challenges in selecting the correct flexible hose for your application.
So how do you know you've picked the correct hose? The STAMPED Method is an industry-wide standard for determining the proper hose. This method is a set of questions that hose distributors should ask customers to help them decide what will work best.
First, size requirements need to be determined. The size refers to the internal diameter of the hose as well as the required length of the hose. The next requirement is temperature, which includes the environmental temperature and the temperature of the media passing through the hose. The third is application. What type of operation will the customer use the hose for? Application might include configuration, routing, aspect, bend radius and flexibility.
Next, any chemicals that might pass through or against the surface of the hose needs to be known. The hose must be compatible with the media to reduce the risk of premature failure. Understanding pressure requirements is also critical because the higher the pressure, the more structurally sound the hose needs to be. Lastly, we need requirements for the fittings and delivery details. Delivery details include customer specifications on testing, quality, certification and shipping of the hose.
Hoses are critical components in industrial settings and facilitate media transportation between trucks, barges, trains and plants, and even between units at the same facility. Hoses in chemical plants and refineries are often exposed to abrasive materials, aggressive chemicals, petroleum products, hydrocarbon products, high pressure, movement and high temperatures. Therefore, metallic hoses are an excellent choice for liquid or gas transfer, especially if any of these factors compromise the hose's integrity during operation.
A metal hose is typically used if the external or internal temperatures are extremely hot or cold because metal has a broad temperature range. Some metal hose can withstand up to 1200° F while maintaining their integrity (temperature derating factors apply). A metal hose also has a higher melting point if fire is a concern. Non-metallic hose types could wear faster due to temperature extremes or melt in the event of a fire.
Metal hoses can also handle a broad range of corrosive chemicals and could provide the best solution depending on the media and application. Stainless steel hoses prevent corrosion due to their outer oxide layer. Corrosion resistance is required in transporting aggressive media or in high-humidity applications. It's also possible to assemble metal hoses with other alloys to enhance their corrosion resistance.
Workers may drag hoses along concrete or other equipment. The hose might also rub against hard surfaces during use. To prevent abrasion, you can protect the hose by adding reinforced wrapping to maintain the assembly's integrity. If the surface of a stainless steel metal hose is scratched, the outer oxide layer will repair itself to prevent rust.
Metal hoses are not as susceptible to permeation as other hoses. Therefore, a metal hose may be your best option if it's crucial to contain gases for operator and plant safety. A non-metal hose could have a higher potential to allow gases to leak into the atmosphere.
A metal hose is generally puncture-resistant and will help prevent pinhole leaks. If a leak occurs on a metal hose, the leak is slower. Non-metallic hoses are more prone to bursting or developing larger cracks. Every crimped or clamped fitting on a non-metallic hose is a potential leakage point. However, on a metal hose, the fittings are welded directly onto the hose, decreasing fitting retention problems. Non-metallic hoses also require multiple threaded connections to connect hoses, increasing the probability of leakage.
Metal hoses might be your only choice if any of these are factors in your application. However, even if the job may not require a metal hose, there are advantages to having the versatility that a metal hose could offer over other hose types.
For more information, visit gopherindustrial.com, call (800) 997-3177 or email djones@gopherindustrial.com.