Depending on the type of application, the hose must have a defined resistance to external and internal pressures.
Two of these pressures are normal.
One is related to the pressure exerted by the fluid and the other is related to external factors such as being pulled by a human or non-human factors.
Today, threaded hoses have had a very good position in the market.
The two most important advantages of threaded hoses over other water and gas hoses are:
- Gives considerable strength to the hose body
- It’s more beautiful.
Today, the sale of threaded water hoses in both Iran and export markets, such as Georgia, Azerbaijan, Pakistan, etc., has grown significantly, and the people of Iran and the world have reacted well to these hoses.
The yarn used in the hose alone does not have a special strength, and when it is combined with the PVC granules in the body of the hose, a strong and significant combination is created, and the body of the threaded hose is more durable than the hose without thread. Please see details nbelow.
The question that may arise when buying and selling threaded hoses is:
What kind of yarn is used in these hoses?
The yarn used in this type of hose is polyester yarn, which does not have a special strength on its own, and when placed next to PVC granules in the body of the hose, it creates a strong and significant composition. The body of the threaded hose has a much higher endurance than the thread less type. Which we explain in detail below
In most modern hoses, such as water hoses, one of the layers used in the body is made of a kind of synthetic yarn called polyester yarn. Since this yarn is made of fibers, a term called “denier” is used to define its thickness.
The unit for measuring the thickness of silk fibers weighing 9,000 meters is called the silk fiber in grams. Therefore, in contrast to the metric number, the higher the denier number, the thicker the silk leaf.
The presence of polyester yarn, regardless of the beautiful and different shape of the hose, has been used only to increase its strength. Here are some of the functions of this thread:
Polyester yarn is always placed between two layers of PVC. These thread act just like rebar ties inside the concrete. Experiments show that the smaller the diameter of the rebars and the greater their number and the dense the structure is, the more durable the concrete will be. Polyester yarn works like this combination, and the more warp and weft become, the higher the hose resistance will be.
The polyester yarn on the outside of the hose looks so weak that it can be easily cut with a sharp knife or a razor. PVC layers alone are not very durable and can stretch when pressed. But when we use these two substances together, a very strong combination is created.
In fact, the combination of PVC layers and polyester yarn makes them so strong that they don’t seem to fit in with common sense. Each of these two substances seems to cover each other’s weaknesses and strengthen their resistance. This yarn reduces the elasticity of the hose to the extent that it lowers its flexibility and does not allow the length of the hose to increase due to fluid pressure or external factors. This is because increasing the length of the hose causes the PVC layers to become thinner, eventually leading to cracking and tearing of the hose.
In a way, this seemingly weak thin string also prevents the hose from tearing when it is folded. Each type of polyester yarn layout, i.e. ring and chain weaving, has its own application, and choosing them is based on the thickness and material of the layers that surround it.