Tube in PSU 3000 mm amber

A tube in PSU is an amber colored, transparent turning blank in polysulfone with a length of 3000 mm. The material's strong suit is hydrolysis resistance: it handles hot water, steam and repeated autoclaving, exactly the environment that breaks many other engineering plastics. That the tube can also be seen through makes it an obvious blank for sight glasses and flow through parts.

Basic data from the source sheet: density 1.24 g/cm³, flammability rating V0 per UL 94 and a maximum service temperature of 160 °C. The low density makes the parts noticeably lighter than the equivalent in glass or metal. The raw material is FDA listed, which opens for direct food contact; as always, check that the use of the finished part falls within the manufacturer's declaration before production locks the material.

Hydrolysis resistance is worth explaining, because it separates the wheat from the chaff among the engineering plastics. Many polymers, for example PET and nylon, are slowly broken down by hot water and steam; the chains are cut, the material turns brittle and the part fails without warning. Polysulfone stands up to it. Parts in PSU handle hot water flushing, CIP cleaning and steam sterilization cycle after cycle, and the material also takes radiation sterilization when the process calls for it.

The transparency is the second practical point. The amber colored view lets the operator see flows, levels and deposits without taking anything apart; sight glasses, inspection glasses in piping systems and level tubes in hot environments are classic PSU parts, not least where PVC and PMMA hit the temperature ceiling long before. The color deepens somewhat with the wall thickness, but the view through remains.

Electrically, polysulfone is a good insulator with stable properties across temperature, and the material can be welded when the design calls for tight joints. Stiffness and strength are at a level that makes threaded and pressed joints entirely possible, and creep is low for an amorphous thermoplastic.

That polysulfone is amorphous is worth knowing. It gives the view through and the stable dimensions, but also a sensitivity to certain solvents; ketones and aromatics can cause stress cracking, so keep the cleaning to water, mild alkalis and the agents the material is documented for. In steam and hot water environments, the grade's home ground, that question is rarely a problem.

The users are found mainly in medical technology, laboratory equipment and the food industry: instrument parts that are autoclaved, valve and pump components in dairies and breweries, inspection glasses in CIP cleaned systems and fitting parts in hot water systems. The Swedish food tech industry is a typical customer; the requirements there combine hot water, aggressive cleaning and regulatory documentation in a way few materials handle as neatly.

The tube format saves material and machine time for ring and sleeve shaped parts, since the rough hole is already there. The dimension program is very wide according to the variant list, and if you need the blanks cut in shorter lengths we arrange that with CTS, our cut to size service. Tubes in amber are also easy to identify in the material rack; no mixing them up with PC or PMMA, which are both water clear. Exact strength values, electrical data and approvals are in the manufacturer's TDS.

Against the alternatives the picture looks like this: polycarbonate is cheaper and clearer but loses out against the cycles of the autoclave, while PPSU takes even more sterilization cycles and harder knocks but costs accordingly. PSU is the proven middle road; enough hydrolysis resistance for most processes, at a more reasonable price tag.

Do you have a sterilization process or cleaning cycle to take into account? Get in touch and we will help you check that PSU fits.