Rubber tubing is used in flow lines for fluids and gases in a variety of pneumatic, hydraulic, medical, process and special applications. Rubber tubing is also flexible and resilient due to its synthetic rubber construction.
Materials:
The different netween rubber tubing from other types of tubing is its rubber-based construction. In Rubber Tubing Rubbers are elastomeric compounds which have high yield strengths which allow them to be stretched more than other materials without suffering permanent deformation. Rubber materials can be classified as either natural or synthetic. Rubbers are known for their flexibility, tear strength, resilience, and thermal stability up to certain temperatures.
Natural Rubber:
Natural rubber is the most important raw material used in the production of elastomers. They are highly resilient and tear resistant, and also exhibit cold temperature. Most natural rubbers have higher elasticity is more than synthetic rubbers, as well as good elastic memory. The drawbacks of natural rubbers include poor ozone resistance and higher cost and and oil resistance.
Synthetic Rubber:
Synthetic rubber is any artificial elastomer. They typically have good fluid and high abrasion resistance and chemical resistance. These are mainly polymers synthesized from petroleum by products. There are a large number of synthetic rubbers; some their properties are listed below.
· Ethylene Propylene (EP): Excellent ozone resistance; high temperature resistance
· Isobutylene Isoprene Butyl (IIR): Low gas permeability; Good weathering and ozone resistance; good heat and chemical resistance
· Nitrile Rubber (NBR): High resilience; high wear resistance; good chemical and temperature resistance
· Polyurethane (PU): Excellent abrasion resistance; good chemical resistance; excellent low temperature performance; excellent mechanical properties and elasticity
· Styrene-butadiene (SBR): Inexpensive; excellent heat resistance; good flexibility and tensile strength
Specifications:
In material selection, rubber tubing must be designed to the accurate specifications for the application.
Sizing:
Correct sizing of tubes is more important for fit in the application. Nominal sizes for tubing are based on the outside full diameter, which measures across the full cross section of the tube. Wall thickness and inner diameter can used to determine the thickness of the tube wall and the flow area for fluid flow inside the tube.
Performance:
Tube performance is typically rated based on the few key specifications.
Pressure rating defines the minimum or maximum pressures the tube is designed to withstand, measured in pounds per square inch. This rating is defined for tubes in fluid flow applications.
vacuum defines the maximum vacuum pressure that can be created in the tube, most frequently given in inches of mercury, referenced below one standard atmosphere.
Minimum bend radius is a rating based on the acceptable amount of deformation the tubing cross-section can undergo, typically given in. This is particularly important for structural applications where the tubing is subject to loading.
Temperature range defines the complete range of ambient temperatures that the tubing is designed to operate within. Temperature affects other performance properties such as oil & chemical resistance,yield strength, and permeability. Operating outside the specified temperature range of the tubing could cause permanent damage or failure.
Finish:
In some applications, More important to consider the finish or color of the rubber tubing.
· Clear tubing is completely see-through, which is important for liquid handling applications where the flow must be monitored.
· Solid tubing is finished with one solid color.
· Translucent tubing allows partial light passage so liquid flow is partly visible and can be monitored.
· Multiple colored tubing is finished with more than one color, either for decorative or indicating purposes.
Features:
Rubber tubes may incorporate a number of features based on the application they are designed for.
· Reinforcement - Rubber Tubing material is reinforced with fibers for added strength.
· Spark resistance - tubing is constructed to maintain integrity in the presence of electrical sparking. This is a important feature for most electrical applications.
Sterilizability - tubing has the ability to be sterilized for sanitary applications: methods include an autoclave, gamma irradiation, dry heat and chemical disinfectant.