Choosing a chemical hose does not depend solely on its diameter, length or price. To make a safe selection, it is necessary to know the product being transferred, its concentration, working temperature, pressure, type of installation and compatibility with the hose’s inner lining.

An incorrect choice can lead to premature hose deterioration, leaks, product contamination and even hazardous situations for operators and the installation. Hose selection should therefore be approached as a technical decision that considers both the fluid’s characteristics and the actual service conditions.

This guide reviews the main criteria for choosing a chemical-resistant hose and determining which solution is best suited to each industrial application.

What Is a Chemical Hose and What Is It Used For?

A chemical hose is a flexible line designed to transport chemicals under specific conditions of safety, compatibility and resistance. It can be used for delivery, suction, unloading, spraying or transferring liquids and, in certain configurations, gaseous substances.

Chemical hoses are commonly used in:

• Chemical production and processing plants.
• Loading and unloading road tankers and railway wagons.
• Port terminals and storage facilities.
• Pharmaceutical, cosmetics and food industries.
• Industrial manufacturing and dosing processes.
• Water treatment plants.
• Professional agricultural applications.
• Operations involving acids, alkalis, solvents, alcohols and other industrial fluids.

Not all hoses used in these industries offer the same level of resistance. A hose for chemicals must be selected specifically for the fluid and the conditions in which it will operate. The general description “chemical hose” does not, by itself, guarantee compatibility with every substance.

Why Chemical Compatibility Is the First Selection Criterion

The first piece of information required is the exact chemical that will flow through the hose. It is not enough to state that it is an acid, alkali or solvent: different substances within the same family can react differently when they come into contact with a particular elastomer, polymer or metal.

In addition to the name of the product, the following factors must be considered:

• Concentration.
• Working temperature.
• Contact time.
• Frequency of use.
• Presence of solids or abrasive particles.
• Possible combination with other products.
• Fluids used during cleaning.
• Changes in concentration or composition during the process.

Temperature is particularly important because it can alter the chemical behaviour of materials. A hose that is compatible with a product at room temperature may no longer be suitable when the fluid is heated or when the process includes cleaning with hot water, steam or chemical agents.

Before selecting a hose, the product’s safety data sheet and the chemical compatibility chart supplied by the manufacturer should be consulted. For critical applications—strong acids, concentrated alkalis, solvents, flammable products, multiproduct mixtures or abrasive fluids—it is advisable to request a specific technical assessment.

A chemical compatibility chart provides an initial reference, but it does not replace a complete analysis of the service conditions.

Chemical Hose Materials: Advantages and Limitations

The material used for the inner lining largely determines which products can flow through the hose. However, the outer cover, reinforcement, spirals, fittings and seals in the complete assembly must also be considered.

No single material is compatible with every chemical. Even PTFE, which is known for its high resistance, must be assessed as part of a complete assembly that includes reinforcement, spirals, end fittings, seals and mechanical working conditions.

Is PVC Resistant to Chemicals?

PVC can be suitable for certain diluted acids, alkalis, aqueous solutions and other products at moderate temperatures. However, it should not be selected automatically for aggressive fluids.

Compatibility depends on the PVC formulation, concentration, temperature and exposure time. Strong acids, aggressive solvents, flammable products or high temperatures may require UPE/UHMWPE, PTFE, composite or another technical solution.

Types of Chemical Hoses According to the Application

In addition to selecting the material, it is essential to choose a construction suited to the type of service.

Delivery Hoses

Delivery hoses are designed to transport products under positive pressure. They are used for pumping, dosing, transfer between tanks and a range of industrial processes.

Suction and Delivery Hoses

These hoses incorporate structural reinforcement that allows them to operate under both pressure and vacuum conditions. They are commonly used for loading and unloading tankers, emptying tanks and other operations in which a pump draws in the product.

Discharge Hoses

Discharge hoses are mainly used to convey a fluid from a tank or storage system to another point in the installation. The pressure may be lower, but chemical compatibility and mechanical resistance remain essential.

Composite Hoses

Gassoflex hoses have a multilayer construction combining different thermoplastic films and spirals. They stand out for their flexibility and low weight compared with other solutions, particularly in large diameters.

They are used for chemical transfer, loading and unloading road tankers and railway wagons, terminals, industrial plants and marine applications. The range includes different configurations depending on the fluid and the inner lining material.

Rubber Hoses

Rubber hoses offer mechanical resistance and can use inner compounds adapted to different families of products. They are an appropriate alternative when the application involves requirements related to abrasion, pressure, intensive handling or harsh external conditions.

PTFE hoses

PTFE hoses are used when high chemical resistance, thermal stability, ease of cleaning or a high level of purity is required. They are common in the chemical, pharmaceutical, cosmetics and food industries, provided that the complete hose construction is suitable for the application.

Metal Hoses

Stainless steel hoses may be suitable for high temperatures, vacuum or certain highly aggressive products. Their selection should take into account mechanical fatigue, vibration, bend radius and the corrosion resistance of the type of steel used.

How to Choose a Chemical Hose Step by Step

The selection process can be organised into eight steps. Following this sequence helps prevent critical information from being overlooked.

1. Identify the Exact Chemical

The product’s trade name and, whenever possible, its chemical composition should be provided. It is also necessary to know its:

• Concentration.
• Density and viscosity.
• Solid content.
• Abrasiveness.
• Flammability and hazardous properties.
• Possible mixtures or contaminants.
• Changes in composition during the process.

If the same hose will be used for several products, compatibility with all of them must be checked and the risk of cross-contamination assessed. A multiproduct solution may require a more resistant inner lining and a specific cleaning procedure.

2. Define the Working and Cleaning Temperatures

Temperature should be assessed at different stages:

• Continuous fluid temperature.
• Thermal peaks during the process.
• Ambient temperature.
• Hot-water cleaning.
• Chemical cleaning.
• Steam cleaning.
• CIP or SIP cycles, where applicable.

The maximum temperature specified in a technical data sheet should not be interpreted as a valid working condition for every product and every length of time. Allowable pressure may also decrease as temperature increases.

Cleaning procedures must respect both the thermal limit and the compatibility of the inner lining. For composite hoses, Gassó recommends adapting the cleaning process to the product and the lining material, without exceeding the working limits specified for each model.

3. Confirm Pressure, Vacuum and Type of Service

The hose should be selected according to the installation’s actual maximum pressure, including peaks caused by pump start-up, rapid valve closure or pressure surges.

It is also necessary to determine whether the hose will operate:

• Only under positive pressure.
• Under suction and positive pressure.
• In gravity discharge.
• In spraying operations.
• Continuously or intermittently.
• In a fixed or mobile installation.

A delivery hose without sufficient reinforcement may collapse when subjected to vacuum. Likewise, selecting a nominal pressure without considering system peaks reduces the safety margin.

4. Choose the Inner Diameter and Length

The inner diameter directly affects flow rate, fluid velocity and pressure drop. An insufficient cross-section can increase velocity, pressure loss and the load on the pump. An oversized hose can be heavier, more difficult to handle and more expensive.

The length should also be limited to what is actually required. An excessively long hose increases pressure drop, makes handling more difficult and increases the risk of twisting or damage.

Measurements in inches normally refer to the nominal inner diameter:

• 1/2″ is equivalent to 12.7 mm.
• 5/8″ is equivalent to 15.9 mm.
• 3/4″ is equivalent to 19.05 mm.

A 3/4″ hose is therefore larger than a 5/8″ hose, which in turn is larger than a 1/2″ hose. However, the dimensions and tolerances stated in the technical data sheet should always be checked. ISO 1307 specifies sizes and tolerances for the inner diameters and lengths of rubber and plastic hoses.

5. Check Bend Radius and Flexibility

A hose must not be operated below its minimum bend radius. Excessive bending can deform its structure, restrict fluid flow or cause fatigue near the end fittings.

Flexibility is particularly important for mobile loading arms, road tankers, terminals, confined spaces and large-diameter applications. In these situations, a composite hose can facilitate handling because of its lower weight and flexibility.

The hose should also be prevented from supporting its own weight at critical points, hanging from its fittings or continuously rubbing against edges and abrasive surfaces.

6. Validate Conductivity, Antistatic Properties and ATEX Requirements

The movement of certain liquids can generate static electricity. The risk increases with flammable products, high flow velocities, loading and unloading operations and work in classified areas.

In these cases, the following should be checked:

• The electrical resistance of the hose.
• Continuity across the complete assembly.
• The connection between the spirals or reinforcement and the end fittings.
• Earthing and equipotential bonding of the installation.
• Periodic testing procedures.

Suitability for an ATEX area must be assessed as part of the complete installation and its risk analysis. Directive 2014/34/EU regulates equipment and protective systems intended for use in potentially explosive atmospheres. However, the assessment should not be reduced to a general claim that a hose is “ATEX compliant”. Its electrical properties, assembly and specific operating conditions must all be evaluated.

7. Select Fittings, Couplings and Assembly Method

Safety depends on the complete assembly formed by the hose and its connections. The type of fitting should be selected according to the product, pressure, connection system and frequency of coupling and uncoupling.

Common options include:

• Camlock couplings for quick connections.
• Flanges for industrial installations and large diameters.
• Sanitary connections for food or pharmaceutical processes.
• Couplings to reduce spills during connection and disconnection.
• Threaded connections and other specialised end fittings.

The material used for the fittings and seals must be compatible with the fluid. It is also important that the assembly is carried out using an appropriate procedure and that the finished assembly is inspected and, where required, tested before entering service.

8. Review the Applicable Standards and Certifications

The applicable standards will depend on the hose construction and its intended use:

• EN 12115: rubber and thermoplastic hoses and hose assemblies for liquid or gaseous chemicals.
• ISO 1307: dimensions, inner diameters and length tolerances for rubber and plastic hoses.
• EN 13765: thermoplastic multilayer or composite hoses for hydrocarbons, solvents and chemicals.
• EN 13766: thermoplastic multilayer hoses for liquefied petroleum gas and liquefied natural gas; it is not a general standard for all chemicals.
• Regulation (EC) No 1935/2004: applicable to materials intended to come into contact with food.
• FDA requirements: where required for the relevant market, product or process.
• ATEX: when the operation takes place in a potentially explosive atmosphere.
• PED: when the assembly and its operating conditions fall within the scope of European pressure equipment legislation.

Not all these references apply to every hose. The required documentation should be established according to the product, installation, country and industry.

Composite Hose vs Rubber Hose: Which Should You Choose?

A composite hose is often particularly suitable when flexibility, low weight and ease of handling are required in transfer operations. These characteristics are valuable in road tankers, terminals, marine installations and large-diameter applications.

The combination of different layers allows the inner lining to be adapted to the product being transported. However, compatibility must be checked for each specific construction rather than for the general “composite hose” category.

A rubber hose may be preferable when the application requires high mechanical resistance, good abrasion performance, specific pressure conditions or a robust construction for intensive use. The type of inner rubber compound will be decisive.

PTFE represents a third alternative for highly corrosive products, high temperatures, frequent cleaning or processes with strict purity requirements. The final choice should not be based solely on the material, but on the balance between compatibility, pressure, vacuum, temperature, flexibility, weight, assembly and maintenance.

Common Mistakes When Selecting a Chemical Hose

The most frequent problems arise from oversimplifying the selection process:

• Choosing a hose based only on price or diameter.
• Using a generic description of the chemical.
• Failing to specify the actual concentration.
• Checking compatibility at room temperature but not at the process temperature.
• Using PVC without consulting a compatibility chart.
• Ignoring suction or vacuum conditions.
• Failing to consider static electricity when handling flammable products.
• Assessing the hose separately from its fittings and seals.
• Exceeding the minimum bend radius.
• Failing to define cleaning procedures.
• Neglecting inspection, support and storage.

Even a correctly selected hose can fail if it is improperly installed, handled or maintained. Hose selection should therefore be integrated into a broader approach covering its entire service life.

What Information Should Be Provided Before Ordering a Chemical Hose?

Before requesting a quotation or technical assessment, the following information should be gathered:

• Chemical product and composition.
• Concentration.
• Continuous and maximum temperature.
• Working pressure and possible pressure peaks.
• Vacuum level.
• Required flow rate.
• Inner diameter.
• Length.
• Type of service.
• Fixed or mobile installation.
• Available bend radius.
• Indoor, outdoor or marine environment.
• Presence of an ATEX-classified area.
• Electrical or antistatic requirements.
• Required standards and certificates.
• Type and material of the connections.
• Cleaning method and temperature.
• Frequency of use.
• Need to prevent cross-contamination.

Having this information available makes it possible to compare solutions using technical criteria and reduces the risk of selecting a hose that is only suitable for conditions other than those of the actual application.

Gassó Solutions for Chemical Product Transfer

Gassó offers different solutions for conveying and transferring chemicals in industrial plants, road tankers, terminals and marine applications.

The Gassoflex Chemical range includes composite hoses with different inner lining materials to accommodate different product families. These include solutions designed for chemicals compatible with polypropylene and other constructions for substances requiring more resistant inner materials, including PTFE. Models such as Gassoflex Chemical SSE, SGT and SST PTFE address different chemical transfer requirements. Each solution should therefore be validated for the specific product and working conditions.

The range is complemented by rubber, PTFE and stainless steel hoses, as well as Camlock couplings, dry disconnect couplings and other connection systems. This makes it possible to evaluate the complete hose assembly rather than only the flexible hose itself.

To select the right solution, it is advisable to provide all relevant application data and request technical guidance. Gassó can help verify chemical compatibility, the assembly method, connections and regulatory requirements before the hose is put into service.

Do you need to select a hose for a specific chemical? Contact Gassó to validate its compatibility, working conditions and complete assembly configuration.

Frequently Asked Questions About Chemical Hoses