Specification for use of hose

Storage of plastic hose

The storage room must be cool, ventilated and dry enough. High ambient temperatures above + 45 ° C without any air flow may cause permanent deformation of the plastic hose. Please note that even in the packaged hose reel, this temperature can be reached in direct sunlight. The permanent stacking height must be adapted to the corresponding product and ambient temperature. The loading weight of hose reel is high in summer temperature and may deform. It is important to ensure that there is no tension in the hose and therefore no stress, pressure or other stress is generated, as tension promotes permanent deformation and cracking. For outdoor storage, plastic hose must not be exposed to direct sunlight. The package shall not seal the hose reel. Depending on the product, the plastic hose must be protected from permanent ultraviolet and ozone radiation.

Transportation of plastic hose

Due to continuous movement, the load on the plastic hose is much greater than that generated during storage. In summer, high outdoor temperature, heat accumulation on the truck and continuous vibration during driving can rapidly lead to permanent deformation of the hose. Therefore, at high temperatures, the stack height during transfer must be lower than the height during storage. During transportation, the plastic hose shall not be thrown, dragged along the floor, crushed or stepped on. This can cause damage to the outer layer, and the helix may deform or even break completely. We take no responsibility. Care must therefore be taken to ensure that improper handling does not cause damage.

Temperature behavior of plastic hose

Unlike rubber hose, cold and hot have a great influence on plastic hose. Plastic hose changes its flexibility at moderate or ambient low or high temperatures. At lower temperatures, they harden until they become fragile. The plastic fluid state can be obtained by passing at a high temperature near the specific melting point of the plastic in the plastic. Due to these characteristics, the pressure and vacuum specifications of the plastic pipe are only related to the temperature of the medium and the environment of about + 20 ° C. If the temperature deviates from the medium or environment, we cannot guarantee compliance with the indicated technical characteristics.

Influence of sunlight on PVC hose

Ultraviolet radiation from the sun attacks PVC hoses and destroys them over time. This is related to the duration and intensity of solar radiation, which is usually less in northern Europe than in southern Europe. Therefore, the exact time period cannot be given. By adding a special UV stabilizer, the brittleness of the UV radiation plastic hose can be slowed down, but not completely stopped. These stabilizers also provide continuous ultraviolet radiation. Some of our hose types are fitted with these UV stabilizers as standard to ensure long service life in direct sunlight. On request, any type of hose can be fitted with UV stabilizers under specific conditions.

Pressure and vacuum behavior of hose

Normal pressure hose is of all types, with fabric as pressure carrier. All hose types with plastic or steel spirals are vacuum hose. All hoses can be changed in length and diameter and can be twisted even within specified pressure and vacuum values. Even under laboratory conditions, the length and circumference of the hose with fabric as pressure bracket is normal. Therefore, all operating conditions that deviate from the specification have a greater impact on the behavior of these products. All hoses with spirals but no polyester fabric reinforcement are only suitable for very limited pressure hose, but are mainly used for vacuum applications. According to the design, the length of these hose types can always change during use, up to 30% of the length, even within the specified pressure and vacuum values. The user must consider all possible length and perimeter variations and the axial twist of the hose during use. Under service conditions, the hose must not be fixed as short as the pipe, but must be able to move freely at any time. In soil, the hose can only be laid in conduit of sufficient size. In this process, all possible variations in the hose geometry should also be considered. We strongly recommend that you determine the behavior of the hose used by pre testing and then install it. When spiral hose is used, elongation and twist under overpressure will result in a decrease in the inner diameter at the same time. For the hose with steel screw, the screw cannot completely follow the decrease of internal diameter. As a result, the screw can pass through the wall of the hose to the outside and destroy the hose. Due to permanent use in the overpressure range, we usually recommend using fabric as the actual pressure carrier hose. This prevents excessive elongation.

Based on DIN EN ISO 1402. – 7.3, the burst pressure of compressed air and pneumatic hose is determined at about 20 ° C, and water is used as pressure medium.

Use hose coupling

In suction applications, plastic screw hose can be integrated with a variety of commercially available accessories. In application, the hose is firmly drawn to the joint and sealed. In pressure applications, spiral hose is much more complex and requires permanent sealing due to strain and diameter variations. The accessories of our product group 989 are customized for a specific type of hose and are very suitable for this. When using standard accessories, please ask for our respective procedure recommendations. Use PVC fabric hose to ensure that the groove toughness of the material is much lower than that of rubber. As a result, the fitting may not have any sharp edges to tear when assembling the inner layer. If the plastic fabric hose is secured to the hose fitting by means of a pressure cartridge or hose clamp, make sure that the pressure is applied with the lowest possible force. Otherwise, the hose layer may be scratched onto the fabric by the connector or hose clip

Post time: Nov-24-2020