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•  Chemical resistance on PVC pipes

PVC pipes have excellent resistance to chemical attack which make them particularly suitable for a wide range of applications.

In normal civil engineering applications PVC push-fit pipes are not subject to chemical attack. However, in contaminated ground or specific foul water and industrial systems, they are highly resistant to strong acids, alkalis and surfactants. They can be used in the presence of sulphuric acid which often exists in abnormal conditions relating to sewerage systems.

PVC piping systems are used in industrial applications for their excellent chemical resistance. However sealing rings are not recommended for these applications and solvent cemented joints are preferred.

PVC is resistant to most oils, fats, alcohols and petrol, but some petrol-based fuels containing benzene cause swelling.

PVC is suitable for use in contact with aliphatic hydrocarbons, but aromatic hydrocarbons can cause unacceptable swelling, even by absorption from the vapour phase¹ .

PVC is resistant to all but the most severe oxidising conditions. Hydrogen peroxide at all concentrations has no effect, and even concentrated solutions of oxidising salts such as potassium permanganate cause only superficial attack.

PVC is generally unsuitable for use in contact with aromatic and chlorinated hydrocarbons, ketones, nitro compounds, esters and cyclic ethers, which penetrate the PVC causing marked swelling and softening. These penetrating solvents may be harmful to PVC even when diluted, but, when they are diluted, their effects fall off noticeably and, at very low concentrations such as are present in many effluents, can be handled safely.

Further guidance can be found in ISO TR 10358.

1 Journal of Institute of Gas Engineers , 2, 3, March 1962, pp185-194