Agru Kunststofftechnik GmbH Austria, has supplied all the piping components made of a high-performance plastic polyvinylidene fluoride (PVDF) for a Hungarian industrial company’s process water plant.

The main challenge this project posed was in making a special part, the “header”, which consisted of a central manifold with an outside diameter of OD 400 mm and several branches. Agru manufactured the header in this size for the first time from its HV Liner product range, laminated with a glass-fibre material for full pressure resistance.

Technical Information: The Agru HV liner pipes and fittings are pre-products for dual laminate systems, which combine excellent chemical resistance of the inside liner material (PP, PVDF, ECTFE) with good mechanical properties of the pressure resistance outside glass-fibre-reinforced plastic (FRP) laminate for long term applications with highest loads.

PURE PROCESS WATER

The industrial company’s existing steel pipeline for process water had to be replaced, as the current steel pipe was unable to deliver the required level of purity due to leaching behaviour and the presence of metallic ions.

Branches are welded to the HV liner pipe using hot-gas wire welding

According to Agru, PVDF, a high-performance plastic, was chosen as the replacement material as it has excellent chemical and leaching resistance compared to metallic materials.

“Given its good thermal and chemical resistance, PVDF plastic is used as lining for pipes and system parts. As it can be made very pure, it can be used in processes such as microchip manufacturing for pipe systems for conveying very pure media like ultrapure water,” said Werner Steindl, senior sales manager at Agru Austria.

“Agru supplies both solid pipes and HV liner pipes for glass-fibre lamination in PVDF. It is therefore possible to reliably supply customers who have applications involving extremely agressive chemicals or very stringent purity requirements and yet have higher operating pressures,” Steindl added.

As this was a very complex process water plant, Agru supplied several hundred metres of PVDF piping with standard dimension ratios (SDRs) of 21 and 33, and several hundred bends, stub flanges and tees made entirely from PVDF.

A PVDF semi-finished sheet with a thickness of 100 mm was used to manufacture the stub flanges, which were machined using Agru›s in-house milling machine. However, the main challenge this project posed lay in making a special part, the “header”, which consisted of a central manifold with an OD of 400 mm and several branches.

FULLY PRESSURE RESISTANT

To make the header, the branches had to be welded into the OD 400 mm PVDF main pipe using a hot-gas wire welding process. To prevent the manifold from losing any pressure, the engineers at Agru opted for a solution that involved an HV liner pipe with glass-fibre lamination.

“Agru’s HV liner pipe consists of thin-walled PVDF and is equipped with a rough, three-dimensional PVDF surface at the factory. This special surface texture will ensure that the glass-fibre laminate bonds to it permanently and securely,” Steindl said. This design also offers other benefits: The economical glass-fibre material guarantees the necessary pressure resistance, while the HV liner pipe, which is only a few millimetres thick, reduces material costs while ensuring chemical resistance and media purity of the system. The customer was particularly pleased by the quick and punctual installation, and was able to put the process water plant into operation according to schedule he added.

Agru is represented in the region by its UAE-based distributor BMC Gulf, which serves regional markets with specialised engineering services and turnkey solutions for industrial and private projects. BMC provides its clients and partners with professional engineering services starting from the design stage to the handover of the project in the fields of environmental engineering, piping systems, water management, concrete repair and plastic welding technology.