The Hose Selection Guide: Heat and cold

Are you looking for a temperature-resistant hose for your process plant? Then this hose selection guide for heat and cold is written for you. Temperature, just like pressure and documentation, is also an important parameter when selecting industrial hoses. 

In this edition of the Hose Selection Guide, we take a closer look at how heat and cold affect a hose, and what you – as a service technician, operations manager or purchaser need to be aware of before ordering new hoses for your process plant.  

Let’s get started! 

Temperature isn’t just a number on a data sheet. It determines how the hose material behaves in operation. As the temperature rises, the molecules in the material move faster, and as it falls, the movement slows down. This affects, among other things, the hose’s flexibility, pressure resistance and chemical resistance. 

In the process industry, you almost always work in Celsius, but what really matters is your temperature profile: What is the normal operating temperature, what temperature fluctuations do you experience, and what stresses arise during CIP, SIP or steam? Without this overview, hose selection quickly becomes a matter of guesswork – and that can be costly. 

So how is a hose affected by temperature? Let’s take a look at some of the most well-known physical properties:

• Hardness: At high temperatures, the hose often becomes softer, which typically increases its flexibility. Conversely, at lower temperatures it can become stiffer, which can make it vulnerable to damage, especially when bent or moved. 
• Abrasion resistance: Temperature does not affect the hose’s abrasion resistance. 
• Chemical resistance: High temperatures can alter the hose’s chemical resistance, making it more vulnerable to certain chemicals or gases in the system. Low temperatures can have the opposite effect.
• Pressure resistance: The hose’s ability to withstand pressure is affected by temperature. For example, a hose operating at high temperatures will have reduced pressure resistance. 

When selecting hoses for high temperatures, you must first determine the type of heat you are working with.  

For CIP cleaning, we often see operating temperatures of around +75–85°C combined with strong cleaning agents. Here, the hose must be able to withstand both the high temperature and the chemical stress without losing its shape, becoming porous or losing pressure resistance. We typically recommend chemical hoses from the Alichem series for this type of application, as they combine an EPDM inner rubber lining and reinforcement, which is suitable for aggressive cleaning media at elevated temperatures. 

If you work with very hot media such as steam or hot oils, the requirements are even stricter, and here it is particularly important to choose hoses that are suitable for these media and temperatures. 

Hoses for low temperatures have different requirements than hoses for hot media. Here, the focus is often on maintaining flexibility and mechanical strength, even in cold environments. This may be relevant in cold stores, outdoor installations, freezer areas or process lines handling chilled products.  

At low temperatures, there is a risk that the hose will become stiff and thus more vulnerable to kinking and mechanical stress. In such applications, it's important to choose hoses designed to retain flexibility in cold conditions – whilst ensuring that pressure and bending stresses do not exceed the material's limits. For extremely cold media in both food and pharmaceutical applications, many of our customers are pleased with our versatile Dynamic hoses. The hoses are all designed to withstand extremely low temperatures down to -40°C, whilst remaining highly flexible in their construction. You will find corrugated, antistatic and high-hygiene variants. 

Temperature and pressure are inextricably linked when selecting a hose. The higher the temperature, the lower the pressure the hose can generally operate at compared to the values shown in the data sheet. 

You should pay particular attention to the following:

• The working pressure must be assessed at the temperature at which the hose is actually operating.  
• The pressure data in the data sheet typically applies at 20°C. 
• Higher temperatures usually mean lower permissible pressure. 
• The combination of heat, pressure and medium can be more demanding than each factor individually. 

You should therefore always know both the operating pressure and the temperature at which it applies. For example, operating at 10 bar at 80°C is quite different from 10 bar at 20°C.

Before ordering new hoses for heating or cooling systems, it is advisable to take a systematic approach. Here are 3 specific tips for the next time you need to buy new hoses: 

• Understand the temperature requirements: You should know the temperature conditions under which the hose will operate. This includes both the surrounding production environment and the medium or media that will pass through the hose. 
• Understand the pressure requirements: Temperature and pressure are closely linked in any process plant. What is the working pressure at the normal operating temperature? As a general rule, the higher the temperature, the lower the pressure at which the hose can operate. Please note that pressure specifications for a hose are always stated at a temperature of +20°C by the supplier. 
• Save money with variants: When buying hoses, it can be a good idea to purchase variants with different temperature limits. That way, you can be sure they’ll fit all your systems and save money by buying the ones that suit your needs. 

If you’re still unsure, it’s better to speak to a technical advisor than to order based on a hunch. 

With over 40 years’ experience in the process industry, there are virtually no application scenarios we are not familiar with. You are therefore always welcome to contact us by phone on +45 7020 0422 or by email at inquiry@alfotech.eu.