How do polymer fittings compare to metal fittings in terms of strength?

Polymer fittings and metal fittings are two of the most commonly used types of fittings in various industries and applications. Fittings are used to connect and join different components or sections of pipes, tubes, and other fluid handling systems. The choice between polymer and metal fittings often depends on the specific application, as both types of fittings have their own advantages and disadvantages. One of the key factors in choosing between polymer and metal fittings is strength. In this article, we will compare the strength of polymer fittings and metal fittings in various aspects.

  1. Tensile Strength

Tensile strength is the maximum amount of stress a material can withstand before breaking under tension. It is an important factor in determining the strength of fittings, especially when they are used in applications where there is a lot of stress on the fittings.

Polymer fittings are generally not as strong as metal fittings in terms of tensile strength. Most polymer fittings have a tensile strength of between 3,000 and 6,000 psi (pounds per square inch), which is significantly lower than the tensile strength of most metals. Metal fittings, on the other hand, can have tensile strengths ranging from 50,000 to 100,000 psi or more, depending on the type of metal.

The lower tensile strength of polymer fittings means that they are not suitable for use in applications where there is a lot of tension or stress on the fittings. For example, polymer fittings may not be suitable for use in high pressure systems or in applications where the fittings are subjected to a lot of vibration or movement.

  1. Flexural Strength

Flexural strength is the ability of a material to resist bending and deformation under a load. It is an important factor in determining the strength of fittings, especially when they are used in applications where they are subjected to bending or flexing.

Polymer fittings generally have a higher flexural strength than metal fittings. This is because polymers are more flexible and have a higher elasticity than metals. Most polymer fittings have a flexural strength of between 10,000 and 20,000 psi, which is significantly higher than the flexural strength of most metals.

The higher flexural strength of polymer fittings makes them suitable for use in applications where there is a lot of bending or flexing. For example, polymer fittings may be suitable for use in irrigation systems or in applications where the fittings are subjected to a lot of movement or vibration.

  1. Impact Strength

Impact strength is the ability of a material to resist cracking or breaking under a sudden impact or shock load. It is an important factor in determining the strength of fittings, especially when they are used in applications where they are subjected to impacts or shock loads.

Polymer fittings generally have a higher impact strength than metal fittings. This is because polymers are more resilient and have a higher resistance to cracking and breaking than metals. Most polymer fittings have an impact strength of between 5 and 10 ft lbs/in, which is significantly higher than the impact strength of most metals.

The higher impact strength of polymer fittings makes them suitable for use in applications where there is a lot of impact or shock loading. For example, polymer fittings may be suitable for use in firefighting systems or in applications where the fittings are subjected to a lot of vibration or movement.

  1. Chemical Resistance

Chemical resistance is the ability of a material to resist the effects of exposure to various chemicals and fluids. It is an important factor in determining the strength of fittings, especially when they are used in applications where they are exposed to corrosive or abrasive fluids.

Polymer fittings generally have a higher chemical resistance than metal fittings. This is because polymers are more resistant to corrosion and chemical attack than metals. Most polymer fittings are resistant to a wide range of chemicals and fluids, including acids, alkalis,

solvents, and oils.

The higher chemical resistance of polymer fittings makes them suitable for use in applications where they are exposed to corrosive or abrasive fluids. For example, polymer fittings may be suitable for use in chemical processing plants or in applications where the fittings are exposed to harsh chemicals.

Metal fittings, on the other hand, may not be as chemically resistant as polymer fittings. Depending on the type of metal, metal fittings may be susceptible to corrosion or chemical attack from certain fluids. For example, copper fittings may be corroded by acidic fluids, while aluminum fittings may be corroded by alkaline fluids.

  1. Temperature Resistance

Temperature resistance is the ability of a material to withstand exposure to high or low temperatures without degrading or losing strength. It is an important factor in determining the strength of fittings, especially when they are used in applications where they are exposed to extreme temperatures.

Polymer fittings generally have a lower temperature resistance than metal fittings. This is because polymers are more susceptible to degradation and loss of strength at high temperatures. Most polymer fittings have a maximum temperature resistance of between 150 and 250 degrees Fahrenheit, which is significantly lower than the temperature resistance of most metals.

Metal fittings, on the other hand, have a higher temperature resistance than polymer fittings. Most metals can withstand exposure to high temperatures without degrading or losing strength. For example, stainless steel fittings can withstand temperatures of up to 1500 degrees Fahrenheit.

The lower temperature resistance of polymer fittings means that they may not be suitable for use in applications where they are exposed to high temperatures. For example, polymer fittings may not be suitable for use in high temperature steam systems or in applications where the fittings are exposed to direct sunlight.

  1. Weight

Weight is an important factor in determining the strength of fittings, especially when they are used in applications where weight is a concern. Polymer fittings are generally lighter than metal fittings, which makes them more suitable for use in applications where weight is a concern.

The lighter weight of polymer fittings also makes them easier to install and handle. For example, polymer fittings may be easier to install in overhead piping systems or in applications where the fittings are located in hard to reach areas.

  1. Cost

Cost is also an important factor in determining the strength of fittings, especially when budgets are a concern. Polymer fittings are generally less expensive than metal fittings, which makes them more suitable for use in applications where cost is a concern.

The lower cost of polymer fittings also makes them more accessible to smaller businesses or organizations that may not have large budgets for fittings. For example, polymer fittings may be more accessible to small scale farmers or gardeners who need fittings for irrigation systems.

Conclusion

In conclusion, polymer fittings and metal fittings have their own advantages and disadvantages when it comes to strength. Polymer fittings generally have a higher flexural strength, impact strength, chemical resistance, and lower weight and cost than metal fittings. However, metal fittings generally have a higher tensile strength, temperature resistance, and may be more suitable for certain applications where weight and chemical resistance are not as important. When choosing between polymer and metal fittings, it is important to consider the specific requirements of the application and select the fitting that best meets those requirements.