Chemical Crossroads

Chemical Crossroads

Our company chemist, David Halley, discusses the most appropriate plastic pipework systems for conveying a variety of chemicals.

The majority of process and manufacturing plants utilise a variety of chemicals within their operations and selecting plant equipment to safely work with specific chemicals can often be a minefield for contractors, consultants and plant managers.

If unsuitable products are installed, the consequences could be potentially disastrous and extremely costly for plant managers. Aggressive chemicals can very quickly corrode unsuitable materials, not only damaging plant equipment and causing plant managers costly downtime and repairs, but any leaks that occur as a result could be extremely dangerous to both the workforce and the environment.

Specifying the correct material is key to a successful installation of any chemical process application and so we are offering advice on the different plastic pipe systems that are available and which chemicals they are suitable for. There is often a misconception that all plastic pipe systems are the same, when in fact each individual pipework material has different properties specially designed to cater for specific applications.

ABS

Designed for low temperature fluid transportation, ABS combines corrosion resistance and toughness to provide the ideal solution for many cold or contaminated water applications, including secondary refrigeration applications. With a wide operating temperature range, the material can cater for fluids up to 60°C, while it remains extremely ductile at temperatures as low as -40°.

ABS is particularly suitable to convey a range of cooling agents including those based on propylene glycol, potassium formate (eg. Hycool) and brine, in addition to low concentration chemically contaminated water. Durapipe ABS is fully WRAS approved and is also listed in the ‘List of Approved Products’ as published in Regulation 31 by the DWI.

PVC-U

Providing excellent chemical resistance, PVC-U is an ideal material to transport a wide variety of process chemicals and industrial fluids at ambient temperatures. Allowing the safe transportation of many acids, alkalis and chemical concentrates without fear of corrosion and environmental pollution, PVC-U offers an operating temperature range of 0°C - 60°C.

PVC-U is particularly suitable for conveying popular process chemicals including Sulphuric Acid, Sodium Hypochlorite and Sodium Hydroxide. Durapipe PVC-U is fully WRAS approved and also meets the requirements of other internationally recognised standards and approvals and is also listed in the ‘List of Approved Products’ as published in Regulation 31 by the DWI.

C-PVC

Purpose-designed to convey hot, corrosive chemicals, C-PVC offers greater protection to the carbon chain compared with PVC-U. Providing excellent performance levels in highly aggressive industrial conditions, C-PVC has the ability to transfer acids and alkalis under pressure and at elevated temperatures.

Typical applications include sulphuric acid, hydrochloric acid, chlorine dioxide solutions and nitric acid. Ideal for high temperature applications, C-PVC offers an operating temperature range of 5°C – 95°C.

Polypropylene

Specially developed to convey the most hazardous of chemicals at elevated temperatures, Polypropylene is often utilised within pharmaceutical, chemical processing and chemical dosing applications. The material of choice for high temperature applications, Polypropylene can cater for operating temperatures between 0°C - 100°C

Offering excellent chemical and abrasion resistance properties, Polypropylene is particularly suitable for a variety of hazardous fluids and is Durapipe’s only plastic pipework system that offers any resistance to Acetone and Cyclohexanol, as well as being suitable for Hydrofluoric Acid.

While there is lots of generic guidance available on chemical suitability, we recommend that specific advice from the pipework manufacturer should always be sought to provide reassurance that the correct system is being installed to safely convey the required chemicals. Durapipe’s company chemist does not only offer advice on the chemical suitability of its different pipework systems, but also provides laboratory testing and analytical investigations into the impact of chemicals on existing systems.

Working with chemicals is always going to come with an element of risk, but it is crucial to minimise this risk where possible. Simply by ensuring the correct materials are installed to convey specific chemicals can safeguard plant equipment, processes, workforce, the environment and the public from any potential danger.


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