Lightweight end fittings offer 30-60% weight savings

17 Dec 2015 Published by


Engineers at Sigma Components – Avingtrans plc’s aerospace division – have produced aerospace pipe fittings offering weight savings of between 30 and 60%.

The fittings are the result of spin off research and development programmes inspired by the company’s successful COMPipe project to develop composite pipe assemblies for use in aero-engines.

“Designing lightweight end fittings was part of the original brief for the COMpipe project,” explained Mike Andreae, director of technology and improvement at Sigma Components. “The design of pipe end fittings hasn’t changed much in over 40 years and when we took an initial look at the designs, it was clear they had been designed for ease of manufacture rather than any weight considerations.

“With environmental concerns driving change across the industry, it’s clear that if we can reduce the weight of key components without negatively impacting on performance, there are real benefits to be had both for fuel efficiency and environmental performance.”

The team at Sigma used the latest finite element modelling techniques to identify changes to the design of traditionally-machined nut, union and ferrules used for straight pipe-to-pipe end-fitting assemblies, immediately reducing the weight of these components by 30%. However, more complex fittings – such as Y-pieces, elbows and flanges – required further thought.

Mike continued: “It quickly became apparent that traditional manufacturing techniques were not going to offer the kinds of weight savings we were looking for on these more complex components so we began exploring the potential of additive manufacturing (3D printing) techniques.

“Working in conjunction with 3T RPD, we secured additional funding from the National Aerospace Technology EP (NATEP) programme, which has opened up a whole world of potential design improvements.

“We have now developed a series of concept designs that are undergoing aerospace validation tests and, with some samples produced in stainless steel already achieving weight savings of 60% compared to their traditionally-machined counterparts, we’re excited by the potential this new technology offers.”