The weight of a gas cylinder makes a huge difference in terms of its real world usability, especially in weight-sensitive industries and in applications where portability is essential.
This desire to cut the weight of cylinders has been the primary driver behind the development and continued adoption of Composite Overwrapped Pressure Vessels (COPVs). Today, composite cylinders are increasingly used across the breathing air, medical gas and oxygen industries, and are gaining market share at the expense of monolithic steel and aluminium products.
In this post, Malcolm Worrall, Director of AMS Composite Cylinders, looks at the development of composite cylinder technology. In addition to a brief history, he examines the real world weight advantages Type III and Type IV COPV pressure vessels offer to end users across a range of industries.
A History of Composite Cylinders – From Genesis to Adoption
Research and initial development
The basic technology for COPVs can be traced back to early 1970s, when a team of NASA scientists were tasked with improving Self-Contained Breathing Apparatus (SCBA) systems for their firefighters.
The aim of this NASA Firefighter’s Breathing System Program was to produce an SCBA system that would cut weight and bulk, whilst maintaining air quality. The solution needed to be robust, with minimum maintenance, and a request for proposal was put out to cylinder manufacturers across the industry.
Several solutions were proposed, including high strength alloy steel cylinders and glass composite overwrapped vessels. The team found that the composite vessels had the potential to deliver a weight saving of around 50%. After further development, the resulting system was accepted by the fire service, and received DOT certification in 1975. Commercial production began shortly after.
Material technology and advances
The successful trials in the fire sector led to continued development of the technology. Glass fibre wrapped vessels gave way to Kevlar COPVs, which were used in NASAs space shuttle orbiter in the 1970s to store large quantities of high-pressure helium and nitrogen.
In the decades that followed, fibre technology moved on significantly, and the Kevlar in COPVs gave way to other materials. The evolution of high-strength fibres enabled the creation of ever-lighter, advanced carbon composite cylinders.
By the 1980s and 90s, new cylinder technology and production advances saw the introduction of lightweight cylinders for other applications, including medical oxygen, rescue services, Emergency Escape Breathing Devices (EEBD) and aviation.
Mainstream adoption and continued expansion
By the late 1990s, carbon composite COPVs had found favour across many sectors, driven by increasing demand for efficient, lightweight storage of pressurised gases.
Today, they are in widespread use across a wide number of commercial, industrial, aerospace, emergency, healthcare, transportation and leisure industries.
As COPV technology continues to develop, delivering further savings in terms of weight, reliability and lifespan, composite cylinders are replacing aluminium cylinders in an ever-increasing number of applications.
Weight Reduction and Real World Benefits
On average, today’s light composite gas cylinders offer a saving of around 50%, when compared to a contemporary aluminium cylinder. This saving can deliver huge benefits to end users in a range of industries.
Healthcare and homecare
Across the UK and around the globe, respiratory conditions such as COPD (Chronic Obstructive Pulmonary Disease) and IPF (Idiopathic pulmonary fibrosis) are on the rise.
For patients and healthcare providers, lightweight oxygen and COPV cylinders have a real benefit. Light composite cylinders can make a huge difference to the quality of life, freedom and independence of elderly and infirm patients using portable oxygen cylinders.
For firefighters on active duty, the benefits of using lighter, less-bulky equipment are significant. In physically demanding, dangerous working environments, small weight savings make a real difference, and lightweight composite cylinders can shave over 35% from the load.
Weight reduction has always been a core goal of the commercial aviation industry – whether it’s improving the fuel-efficiency of passenger airline jets, or maximising ETOPS (Extended Range Operation with Two-Engine Range).
In aviation, every kilo counts. Using COPV cylinders provides a valuable reduction in the weight of the numerous oxygen cylinders on-board the aircraft.
Lightweight COPV Cylinders from AMS
AMS Composite Cylinders is the exclusive continental European and UK distributor for an advanced range of lightweight gas cylinders from Advanced Material Systems (AMS).
Products include carbon composite cylinders for a wide variety of breathing air and oxygen therapy applications, including healthcare, respiratory, SCBA (Self-Contained Breathing Apparatus), laboratory, emergency and environmental uses.
Our light composite gas cylinders offer high pressure (300 Bar), NLL (Non-Limited Life) performance, and are accredited for use worldwide – holding a wide range of quality assurance accreditations, including: ISO 11119-2, UN-TPED Pi, DOT (USA) and TC (Canada).
Additional information about AMS Composite Cylinders and our products can be found at www.ams-composites.com.