Hollow Bar in PEEK Victrex 450 250 mm beige

A hollow bar in PEEK Victrex 450 solves the classic problem when you need to carry or protect media where metal corrodes and cheaper plastics melt. The unreinforced base grade of PEEK handles 260 degrees continuously and takes 300 degrees at shorter exposures. The lowest temperature lies deep below zero, so the same tube can be used both in hot steam and in a cryogenic environment without losing toughness.

The material is V0 rated on the flammability scale and has a tensile strength around 116 MPa. The water uptake is negligible, only 0.03 percent, which means the tubes keep their dimensional tolerances even in damp environments. The hardness sits at about 253 N/mm². That means the tube wall takes both internal pressure and external handling without deforming or cracking.

Chemically PEEK handles strong acids, bases, oils, fuels, steam and most organic solvents. The tubes are therefore common in sterilization equipment, semiconductor processes, chemical engineering plants and high temperature processes in food and pharmaceuticals. Radiation resistance is good, so they work even where the material is exposed to gamma or other ionizing radiation.

As a format the tube is optimized when you need flow, insulation or protection rather than a solid part. Typical uses are process tubes for aggressive liquids, protective tubes for thermometers and sensors in high temperature environments, insulating sleeves in power electronics, carrier systems for heating elements, transport channels in semiconductor manufacturing and liner tubes in medical autoclave equipment. In the oil industry PEEK tubes are used as a protective wrap on downhole components where pressure, heat and fluid are all aggressive.

For machining you pick sharp carbide tools and a moderate feed. The chip carries the heat away with it, so avoid chips packed into a tight space. PEEK is thermally insulating, which means you can usually turn dry or with air blowing. The material can be threaded both internally and externally, cut on a saw and ground to final dimension. For heavy walls and high precision, annealing after rough turning is recommended to release residual stresses.

Bonding requires a primer or plasma treatment, but mechanical connections with cutting rings, clamping rings and flanged transitions work very well. PEEK can be welded with hot gas, but that is specialist work and suits larger lines in the process industry best.

The choice of dimension is governed by the flow, the pressure and the temperature. For higher pressure you choose a greater wall thickness; for media transport where insulation matters a thicker wall can also bring advantages. Outer and inner diameters are chosen so that couplings and connections fit standard fittings or custom made nipples.

Get in touch with the pressure rating, the chemistry of the medium and the temperature requirement, and we will pick out a dimension that matches your application.

The short 250 mm piece in Victrex 450 suits individual turned rings in pure PEEK.