Having the right hose in your plant or factory is crucial because it ensures that systems perform at optimum levels, increasing uptime, and even ensuring your employees’ safety. It also reduces costs you may incur in maintenance and replacements. Therefore, the type of material you choose for your hose should be of the highest quality. Selecting the wrong hose may lower profits, increase downtime, and even cause danger to employees.
With so much to lose, what should design engineers and maintenance technicians consider when choosing and specifying hoses for their machines and equipment? Maintenance and replacement costs, hose life, and other factors should all be considered when making the final decision. Factors that may influence your best choice and affect your equipment’s performance are profoundly affected by the hose material options, construction type, the end connectors, and the applications it will be used for.
Hoses are made up of several components: the core, end connectors, coverings, and reinforcements. These are also crucial to determine the type of hose you select to use in your plant or factory. Let us look at each component individually, and see how each will improve system performance, costs, and workers’ safety.
Hose Core
It’s vital to select the right material for the hose core because this is the part of the hose, which handles most of the work. The type of medium determines the kind of material you choose for the hose core and what applications you’ll use it for, whether gas or fluid. This will be determined by the core’s chemical compatibility and permeation. The core must also be able to handle the liquid or gas inside without degradation. The core should also not affect the fluid and must withstand the rapidly changing temperatures and pressures.
Here are a few common materials used to make hose cores.
Metal
Metal is a common choice for many hose cores and is used in many fluid subsystems. Metal is made of stainless steel and is an excellent choice because it can handle extremely high temperatures. Flexible metals are also ideal if your requirements include low permeation. If you’re looking for metal cores that can handle unique applications that require high temperatures or chemical compatibility, you should purchase from aero flex that specializes in fabrications of custom-made hose assemblies.
However, if your applications include caustic or acidic fluids, metal isn’t the right choice because these fluids will cause corrosion. Metal cores are also known to fail due to wear caused by vibrations and repetitive movements.
Silicon
Silicon cores are ideal in applications where cleanliness is crucial, such as pharmaceutical processes or food and beverage plants. This is because it’s very flexible and is compatible with various sanitary requirements and wash-downs. Silicon, however, can’t withstand very high temperatures because it becomes brittle and can break down.
Silicon is also very absorbing, and this can lead to hose contamination. Although it’s flexible and easy to clean, it’s incompatible with some chemical solvents and detergents, so you should be careful about which detergent you’re using when you have a silicon core. Even steam cleaning, an effective sterilization method, may not entirely clean some of the silicon core’s absorbed fluids.
PTFE
PTFE cores are quickly replacing silicon cores because they can handle slightly higher temperatures and eliminate the drawbacks of cleaning. They are far easier to clean as they can withstand repetitive steam cleaning. They are also non-stick, non-aging, and have low absorption rates, reducing risks of contamination.
Their only drawback is that they are more permeable than metal, and this makes them unsuitable for hose applications that can’t handle permeation. Also, fluids and gases tend to generate electrostatic charges when passing through PTFE cores. In some cases, it leads to static sparking, which damages the hose and can be a safety hazard. To mitigate sparking from your hoses, request a carbon black filled core depending on your applications. Carbon will let the charge move to the end connectors and dissipate safely.
Nylon (thermoplastic)
Nylon is a popular choice for most hydraulic cores. They can withstand high pressures, however limiting their use in high-temperature applications. They can withstand vibrations and pressure impulses more than metal or PTFE cores, so they are an excellent choice for general-purpose hoses. However, they are porous and soft, making them highly absorbing and can cause contamination.
Rubber
Rubber is an excellent choice if you’re looking for a versatile and durable hose core. It can be crushed without causing permanent damage, and can be assembled with little to no specifications. Its temperature range is the same as that of nylon.
However, rubber cores are limited to less than 500-psi applications, and it erodes faster than the other options.
Core construction
When choosing your core material, the core construction is also a significant factor to consider. There are two options when looking for core construction, and these are smooth bore and convoluted bore. When deciding between the two, applications’ flow, pressure, drain ability, and flexibility should be a factor in your final decision.
If precise flow control is a priority in your applications, then the smoothbore construction is the better choice. Its smooth walls ensure no flow irregularities. They promote good drainage such as transfer lines where the media may change, and you wouldn’t want contamination. However, smoothbore cores are susceptible to kinking, especially if the hose has a big diameter.
If you want to avoid kinking, use the convoluted cores. This is because it consists of folded walls that let the walls bend easily. There are two types of convoluted cores – annular and helical. Annular cores are commonly used on metal cores because they have convolutions created by a series of connected rings. Annular cores are ideal when maximum flexibility is needed. However, they aren’t suited for processes with repetitive motions as it causes wear and breakage.
On the other hand, helical cores are made of a single fold that spirals the length of the hose, commonly found in PTHE cores. A helical core improves downstream flow that improves draining and flexibility.
End connectors
End connectors are mainly used to connect components to other media handling devices safely and securely. Same as hose cores, there are different types of end connectors. Different end connectors perform differently, which improves efficiencies and fluid or gas quality.
The material you choose for the hose determines the material used on the end connectors. For metal hoses, the connectors are welded to form a permanent seal. PTFE materials and other non-metallic materials are usually crimped or swaged. Both methods are typically accepted, but crimping, which presses on the end connection rather than on the hose, is less likely to destroy the hose because the pressure is carefully applied.
It’s vital to note that end connectors shouldn’t cause twisting to the hose during installation, as this could cause premature failure.
The industry you’re in determines the type of end connector you require. For example:
Pharmaceutical, biopharmaceutical, and biotechnology
The topmost priority for these industries is cleanliness and maintaining a high sanitary environment. When choosing your end connectors and in any of the industries like pharmaceutical, biopharmaceutical, or biotechnology, they should be easy to maintain cleanliness. This could be done either by the clean-in-place (CIP) process or by taking them apart. The material used should be able to resist corrosion and prevent bacterial growth.
General industrial markets
For most industrial processes, what they consider most is end connectors that can withstand high pressure. End connectors used in these applications must meet or exceed the hose’s pressure rating and be assembled, so that when a failure occurs, it won’t separate from the hose but only in the hose being compromised.
Semi-conductors
In the production of semi-conductors, the main priority is material purity. Materials used in making end connectors used in these industries should be of the purest form due to their use in sensitive environments, designed and coated with substances that cause less permeation to avoid contamination, and finally, should be made with fine threads.
Coverings and reinforcements
The hose coverings and reinforcements are determined by safety, flexibility, and pressure containment.
Covers
These usually consist of the outermost layer on hoses, and they are used to protect the underlying layers and your employees working nearby or on the surrounding equipment. They come in various materials like silicon, which is excellent for covering stainless steel reinforcement braids, and prevents it from fraying. Silicon covers also protect workers from bumps. It also helps by adding insulation, thus maintaining fluid temperature, eliminating bacteria buildup.
Fiberglass is an excellent material used in covering and helps in preventing burns and fires.
Reinforcements
These are typically used to cover the hose’s core in a flexible woven stainless steel braid. Excellent reinforcement layers help improve hose’s flexibility and pressure containment.
Conclusion
Many different factors influence the type of hose you need for your applications. This guide has highlighted the different types of hose materials, and what the applications they are best suited for.