Why Are There So Many Types of Hoses?

In every industry hoses are separated into dozens of categories, and several sub-categories, based on their use in specific applications. A few of the common hose categories include: air & multipurpose, chemical transfer, food, petroleum transfer, steam, water, hydraulic, and ducting. Each of the hoses used in these applications have various features which differentiates them from each other.

By reviewing the various types of hoses, hose constructions, and the key features of the most common types of industrial rubber, PVC and ducting hose, one can answer the commonly asked question, ‘why are there are so many different types of hoses?’

By Karina Robinson, Market Director, N.A Industrial Hose, Continental and Ross Blanford, Director of Sales for North America, Masterduct

The simplest answer, to the query concerning hose categories, is: hoses are designed to meet very specific criteria, and therefore fall into groups based on their various attributes. A more in depth look at hoses, however, shows that an application’s requirements may dictate that a particular hose is most suitable based on the I.D. of the hose (Size); the internal and external (Temperature); the specific (Application), what (Material) is going through the hose, the (Pressure) requirement, the type of fittings or (Ends) and when the customer requires the hose (Delivery). In the industrial hose industry, the information which needs to be gathered to determine the proper hose is referred to as STAMPED. Through the STAMPED process, the best hose can be determined for the application.

Construction of a Hose

Hose construct.

When looking at the make-up of hoses, it quickly becomes apparent that they are all constructed with three main components; a tube, reinforcement, and a cover.

The ‘tube’ transfers material, in any state (gas, solid, liquid, or chemical) from point A to point B. In order to ensure that the transfer of material is successful, the tube must be compatible with the substance traveling through it. If, for example, the application needed to convey oil, the tube would have to have a high oil resistance. In addition, a tube could be required to be resistant to abrasion, heat, and specific chemicals. The tube must therefore be compounded to handle the specific application.

The ‘cover’ acts as the hoses protection. Depending on the application, the cover can also be resistant to oil, acid, abrasion, flexing, heat, and ozone. It is often a different compound than the tube and its exterior may be smooth, wrapped, or corrugated. Once the hose cover begins to wear away, the hose should be monitored closely and will likely be nearing the end of its useful life. If the hoses reinforcement is showing through the cover, the hose should be replaced immediately.

The ‘reinforcement’ provides the hose with its overall strength and rigidity. It is designed to handle either positive PSI or negative vacuum pressures. There are typically three types of reinforcement.

  • Braided: a braid of a synthetic textile (polyester, rayon, nylon, aramid), or other material such as PVC, steel or a combination to create a lightweight or heavy-duty hose;
  • Spiral: a spiral wrap that is made from natural fibers, synthetic materials or wire;
  • Helical: a helical coil. If there is a helical wire in the hose, this will help create a vacuum rating and can be used in suction and discharge.

Types of Hoses

Air & Multipurpose hose.

When looking at the various types of industrial hose, those used in: Air & Multipurpose, Chemical, Petroleum, Food & Beverage, Steam, Water, and Ducting, are the most common. Of the listed groups, Air & Multipurpose has the most frequently used range of hoses, due to their application across a wide network of industries. Air & Multipurpose hoses are categorized into three subgroups, general, heavy duty, and push-on hose, and will typically have a Class A, Class B or Class C rating, based on the degree of oil resistance. Typical hose working pressure ratings fall between 200 PSI to 300 PSI but can go up to 500 PSI to 1,000 psi for heavy duty.

Chemical Transfer hoses can similarly be found in several industries including petrochemical, paint processing, and waste water treatment. Its most common tube constructions are ultra high molecular weight polyethylene (UHMW), which can withstand 98% of all chemicals, and modified crosslinked polyethylene (XLPE), which handles 93%. They key to making chemical hose recommendations using STAMPED, is to determine the chemical compatibility of the hose in conjunction with the temperature rating. To ensure that the proper hose is selected, most hose manufacturers have a chemical chart to reference that depicts compatible temperature ratings and concentrations. Typically there is more than one recommendation. There are times, however, that only one or no recommendation is available. When there are no recommendations, users should reach out to the hose manufacturer for guidance.

Petroleum hose is another common application for industrial hose. Petroleum hose is used in oil & gas, gasoline dispensing, tank truck transfer, aircraft refueling, and dock unloading. The most common tube compounds for these applications will be nitrile formulations, based on the specific application and aromatic content. It is advised for user to be mindful of biodiesel applications, as they typically take a specially formulated nitrile in order to transfer the material. A standard nitrile may turn very gummy if exposed to biodiesel.

Food & Beverage application is also always a very stable industry for industrial hoses. Food & Beverage hoses must use FDA compliant materials and are commonly fabricated with a rubber, PVC, or polyurethane material. This type of hose can transfer either a liquid or a solid, and requires a resistance to oil, abrasion and the ability to transfer a certain type of alcohol.

Types of hoses.

A steam hose is used in refineries and various plants for heating, cleaning, and thawing pipes. The common tube materials is ethylene propylene diene monomer (EPDM), followed closely by Chlorobutyl. As safety is a key factor on steam hoses, the burst rating must be a minimum of 10:1; this mean that a 250 PSI rated steam hose burst rating must 2,500 or greater.

Water Suction and Discharge hose is commonly found in construction, water treatment, rental equipment industries. The rubber compounds for these hoses are EPDM or styrene-butadiene, and they are typically rated with 150 PSI for up to 12” I.D. (or larger). PVC is also sometimes used in this industry. The main differences between a rubber and a PVC water S&D hose are the pressure ratings, temperature rating, and pricing.

The last category to review is Ducting. Ducting hose is frequently found in air movement, dust collection, exhaust, material handling, leaf collection, and removal of toxic fumes. Sizes of these hoses range up to 36”, and are typically categorized by material and application. Ducting hose has a wide variety of options available depending on the application. Fabric ducting can also be made in anti-static and electrically conductive forms as well as with a stainless steel helix which makes it acceptable for use in food and pharmaceutical applications. There can even be protective coatings added to the ducting hoses for abrasion resistance, flame resistance or to make static dissipative. For high temperature applications, aluminum, stainless, fiberglass, or silicone may be used. There are two unique types of ducting hose: electrically conductive ducting and fabric ducting. Electrically conductive ducting has carbon black integrated into the material and particularly unique because there can be multiple grounding options, which will help prevent ignition of a combustible materials.

Electrically Conductive Ducting hose.

Fabric ducting is also very popular and used in a variety of applications with dozens of specifications available. Common applications are air flow, high temperature, fumes, chemicals, and gases. They can also be used in agricultural and automotive ventilation, along with applications requiring flame retardant ducting.

Final Thoughts

In closing, the main message to take away is that there are hundreds of types of hoses available due to the various application requirements in many different types of compounds and materials. There is often more than one right hose for an application, but it is important to use STAMPED to determine the proper hose recommendation. It is also beneficial to visit www.hoseselect.com to help make a hose recommendation utilizing STAMPED information, or for ducting hose recommendation, please visit: http://www.masterduct.com/SearchProducts.aspx. Choosing the correct industrial hose and/or ducting hose is critical and is easy to do by following the process. Using the wrong hose can not only be a costly mistake but also pose a safety risks to the operator. If a user is in doubt, he/she is encouraged to reach out to the hose distributor or manufacturer for assistance.

ABOUT THE AUTHORS

Karina Robinson has 24 years of experience in the industry. She has progressed with Continental ContiTech serving as a Technical Manager, Product Manager, Industrial Hose Marketing Manager and now as Market Director N.A. Industrial Hose. Karina is a member of the NAHAD Standards Committee.

Ross Blanford has 28 years of experience in the industry. He is a sales, management & marketing professional with experience as a principal of a manufacturer’s representative agency, as a regional and national sales manager and for manufacturers of various sizes.

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