Understanding Chemical Hoses for Safe Operations

Hello everyone, and welcome to the VELON Chemical Hose Knowledge Class. Since the dawn of human civilization, chemistry has been closely intertwined with our lives, from the simple firing of pottery and smelting of metals to modern applications in medicine, food, energy, and materials. Hoses play a crucial role in transferring chemical materials, ensuring the safety of personnel, equipment, and the environment. Choosing the right hose is vital for safe production. In this lesson, we will explore the basics of chemical hose products, including their properties, common classifications, static dissipation capabilities, and applications.

First, let's look at the basic properties of chemical hoses. These are industrial hoses specifically designed for the safe and efficient transportation of various chemicals and fluids. As part of the industrial hose family, they possess typical characteristics, such as a standard three-layer structure: the inner layer, reinforcement layer, and outer layer, each serving a different function. The focus here is on the inner layer of the chemical hose. Due to the need to resist various corrosive media and considering cost, there are many choices for the inner lining material of chemical hoses. Based on the type of inner rubber or lining material, we classify chemical hoses into NBR, EPDM, FKM, polyethylene, and fluoropolymer hoses. In terms of corrosion resistance, fluoropolymer hoses are the strongest, followed by polyethylene hoses, with rubber hoses being relatively weaker.

Rubber Chemical Hoses: Whether it's NBR, EPDM, or FKM, they are all made of rubber material. They can conditionally resist some common chemicals, such as gasoline, diesel, and low-concentration acid and alkali chemicals. However, rubber materials usually cannot handle solvent chemicals. To enhance the hose's corrosion resistance, we typically add a plastic film layer to the inner layer of the hose, which is how polyethylene and fluoropolymer hoses came to be.

Polyethylene Chemical Hoses: There are usually two types of inner layers, XLPE and UPE. XLPE is cross-linked polyethylene, and UPE is ultra-high molecular weight cross-linked polyethylene. UPE has greater corrosion resistance than XLPE and is more commonly used as a lining in domestic applications. UPE is quite resistant to corrosion, with statistics showing it can withstand over 90% of common chemical media, such as strong acids, strong alkalis, and various solvents. Its corrosion resistance is second only to fluoropolymer hoses. UPE chemical hoses offer excellent value for money.

Fluoropolymer Chemical Hoses:Fluoropolymers include various materials like PTFE, FEP, PFA, etc. While they differ in some performance aspects, they are almost equally resistant to corrosion. Except for a few special media, fluoropolymer hoses can withstand the erosion of almost any chemical in nature. However, these hoses are relatively stiff, have a larger bending radius, and are the most expensive.

Next, we share some professional knowledge about the static dissipation capabilities of chemical hoses. As we all know, chemicals can be dangerous, and many are non-conductive, with characteristics such as flammability and explosiveness. During the transportation of chemicals, friction can generate static electricity, which, if not dissipated in time, could lead to explosions and other safety accidents. Therefore, chemical hoses must meet the requirements for static dissipation. We refer to the European chemical hose standard EN12115 and explain four types of static dissipation capabilities.

1. Ω+T type: This is the highest level of conductive hose, with both inner and outer layers meeting static dissipation requirements. This requires a special formulation of the hose material, typically adding sufficient conductive carbon to rubber or plastic. According to the static dissipation test standard method (standard number IS08031), the inner wall insulation resistance of this type of hose is less than 1 megohm, and the insulation resistance from the inner layer to the outer layer is ≤ 1000 megohms. This type of hose can be used in the most demanding explosion-proof environments. The inner layer of the hose is usually black or has conductive strips, and the outer rubber is black.

2. Ω type: Compared to the first type, this hose reduces the requirement for static dissipation from the inner layer to the outer layer. It only requires the inner layer of the hose to have static dissipation capabilities. According to the static dissipation test standard method, the inner layer insulation resistance of this type of hose is ≤ 1 megohm. The hose is suitable for transporting flammable and explosive media and can be used in explosion-proof workshops with general requirements. The inner rubber of the hose is usually black, and the outer rubber can be colored rubber.

3. M/T type: This type of hose only requires static dissipation capabilities from the outer layer, with an outer layer insulation resistance of ≤ 1000 megohms according to the static dissipation test standard method. These hoses have copper wires or steel wires in the middle layer, which are conductors. When making hose assemblies, copper wires or spiral steel wires are needed to reliably connect with the fittings at both ends. The outer rubber of this type of hose is usually black, and the inner rubber is colored. This type of hose is not common.

4. M type: The inner and outer rubber of the hose does not have static dissipation capabilities. However, the hose has spiral steel wires or conductive copper wires, and reliable connections are achieved through steel wires or conductive copper wires when making assemblies. This product does not have static dissipation capabilities, and there is a risk of the metal wires breaking.

Finally, we share typical application scenarios for chemical hoses:

1. Lithium Battery Industry: Chemical hoses are mainly used in the production, filling, and transportation of electrolytes in the lithium battery industry, as well as the transportation of positive electrode solvents and the transfer of lithium battery slurry. Over the years, chemical hose products have basically achieved domestic replacement. Common hoses used according to different working conditions include UPE and PFP chemical hoses.

2. Chemical Industry: In fact, active pharmaceutical ingredients also belong to the chemical industry. Chemical hoses are widely used to transport various corrosive chemicals in the chemical industry, such as sulfuric acid, hydrochloric acid, and liquid alkali. Common scenarios include oil tanker unloading and factory transfer stations. Chemical hoses are selected based on the different media.

3. Fine Chemical Industry: In the material transfer or filling processes of factories such as daily chemicals, fragrances, and coatings, many media are non-conductive materials. Therefore, hoses generally have static dissipation functions and usually choose Ω static dissipation type hoses.

In summary, in this lesson, we shared information about chemical hose products. We know that chemical hoses are a category of industrial hoses with a basic three-layer structure. To meet the compatibility needs of different chemical media, the inner rubber can be made of rubber and special plastic materials. Considering the special nature of the chemical hose usage environment, there are four types of static dissipation capabilities available. For chemical hoses, we must judge and select the appropriate product based on stamped information to avoid selecting the wrong product and causing production accidents. Of course, we also welcome you to directly consult our sales team. Our team members have more than ten years of experience and should be able to help you choose the right chemical hose.