Leak Testing: Pressure Decay Explained

Cyan Tec Systems Limited (Cyan Tec) specialises in the integration of leak and flow test equipment which includes the supply of semi-automated and fully-automated systems into a wide range of different industry sectors. When talking specifically about leak testing, Cyan Tec has often adopted the pressure decay method to meet their customer’s demands.

bespoke-leak-test-tooling

Bespoke leak test tooling

The straightforward but effective technology that is well-known within the industry as pressure decay has now become a mainstay where high volume production testing is required and Cyan Tec has used its expertise in the design and manufacture of high-end automation systems to work alongside all the leading suppliers of leak test instruments to offer a quality solution. Strong working relationships with the aforementioned suppliers allow Cyan Tec to offer the end user the required after-sales support that is a key element in this type of project.

Pressure decay leak detection instruments are frequently associated with the checking of components that have relatively small volumes. The chamber is filled with air and the pressure transducer built into the specialist leak test instrument monitors the pressure for negative changes where any pressure drop indicates a leak.

automatic-leak-testing

Automatic leak testing

The pressure decay technique can also be referred to as gauge decay leak testing or absolute pressure leak testing. This is due to the method of leak testing simply measuring the drop in pressure on a gauge (transducer) during the leak test.

Although Cyan Tec is a UK-based company predominantly supplying leak testing equipment on home turf, having a strong reputation in this particular industry has also provided opportunities to supply leak testing machines to ‘Blue Chip’ companies on the continent. The product knowledge, reputable name and the high-quality end product associated with Cyan Tec gives the end user of the leak test equipment the confidence that the required skills are available in-house to offer expert advice no matter how simple or complex the automation.

Cyan Tec Systems Exhibiting at MACH 2016 Show

MACH2016

Cyan Tec Systems will be exhibiting state-of-the-art capabilities in industrial automation and laser systems equipment at the MACH 2016 Show from 11-15 April 2016.  Experts will be available on Stand 4360 in Hall 4 of the NEC, Birmingham, to discuss potential applications in automation and laser material processing.

With a team of dedicated designers, Cyan Tec can provide standard or bespoke laser processing machines for laser welding, laser cutting, laser marking (engraving) and laser drilling.  Building on several decades of experience, Cyan Tec is perfectly placed to provide automation solutions, including assembly, leak testing, machine loading and unloading, robot systems, clean-room automation and automatic spraying systems.  Solutions from Cyan Tec are used in the automotive, aerospace, medical device and pharmaceuticals, electronics, plastics and food industries.

Working with the industry leading robot, conveyor, pick & place and laser systems suppliers, Cyan Tec can provide and support automation and machinery all over the globe, from its base near Loughborough in Leicestershire.

New enquiries for automation and laser processing are welcomed, and the team at Cyan Tec can provide anything from design through to complete turnkey system delivery and installation.

Cyan Tec is situated in the AILU (Association of Industrial Laser Users) Pavilion on the South side of Hall 4 at the NEC.

 

 

 

Automotive Component Leak Testing

When a high-profile automotive supplier needed a suite of customised leak testing systems for their latest engine components, they had no hesitation in contacting Cyan Tec Systems who had previously provided several automation machines for their UK factory. In order to fulfil the customers’ requirements, Cyan Tec provided a total of six individual leak testing machines, each designed to suit specific engine components.

To verify the quality of high performance engines, it is necessary to perform accurate leak testing of components and assemblies, the most commonly used method being “pressure decay” which has been used for several decades to identify faults in sealing or component integrity. Using this method, air is injected into the test object which has been sealed to allow a build-up of pressure. The pressure is then monitored over time, any decay of pressure indicating a leak. In this case, it was the high-level testing of the casting integrity that was required.

Cyan Tec has established a track record in automated leak testing, using third party leak testing equipment integrated into the production lines of many clients.  In particular, Cyan Tec has a strong relationship with Ateq, a well-known supplier of differential pressure decay leak testing equipment.

After assessing the requirements of the customer, Cyan Tec provided the six machines based around a modular design. Each machine has a fabricated metal base frame, providing a rigid support structure for mounting of the various machine elements.

All the machines provided are manually loaded by an operator and wherever the parts are too heavy to be lifted, the operator is assisted by appropriate lifting equipment.  To simplify operation and eliminate human error, the operator uses a handheld scanner to scan the barcode on the component or assembly to identify and record the product variant which is to be tested.

 

All the orifices on the component under test are sealed by O-rings on the bespoke tooling which are closed onto the part using a combination of pneumatic cylinders and manual clamps. With the design and manufacture of such intricate tooling being a critical aspect of the leak testing process; the wealth of knowledge that Cyan Tec has in this area was absolutely vital to ensure that the project was a success.

Once the component is detected as “in place” and the variant is verified by the barcode reader, the automated leak testing process is initiated by the operator pressing the start button. On completion of the test sequence, the result is displayed as a green or red light (for pass or fail) as well as being displayed on the HMI (Human Machine Interface), located in front of the machine. Parts are then unloaded and new parts loaded by the operator.

Each machine is customised to suit one or more products, the machine construction providing a combination of guarding and safety light curtains to ensure that the operator is well-protected during the testing sequence.

Cyan Tec is an experienced manufacturer of laser processing systems, robotic automation and automated leak testing systems based in The Midlands, United Kingdom. Standard and custom systems are offered with a full service from design through manufacture, supported by a dedicated team of engineers.

How is laser welding better than TIG?

Arc welding as a production process took a long time to become established, but has nevertheless been around since the 1940s.  Although the laser was only invented in 1960, it quickly became established as a production process and by the 1980s was starting to be used in high volume manufacturing.  Recent advances which have improved the beam quality and efficiency of lasers, make the laser an even more advantageous solution to high volume or automated industrial joining.

Weld quality and consistency

Laser welding enables the quality and consistency of welding to be readily controlled and consistently maintained.  Since the laser head makes no contact with the workpiece and there is no electrode which can become worn, eroded or damaged there is no need for a tool change where the electrode needs to be reground or sharpened, as is the case with TIG.  The lack of electrode dressing in laser welding results in higher uptime and longer time between maintenance interventions.  Also, there is no risk of contamination of the weld material with Tungsten from the TIG electrode tip when striking the arc.

Lower heat input

With laser welding the heat input to the metal being welded is lower which means there is a smaller heat affected zone (HAZ) and the distortion of the assembly is vastly reduced making complex and accurate assembly more achievable, especially in an automated setting.

laser weld microTIG weld

TIG welding (left) typically exhibits higher heat input into the surrounding material – Laser welding (right) is capable of finer welds, with a much smaller heat-affected zone

In addition, the lower heat input means that a weld can be placed close to sensitive electronics or other heat-sensitive materials without risk of damage or failure.  An example of this is in cardiac pacemakers and defibrillators where the external weld seam is directly above a heat-sensitive battery and micro-electronics which cannot withstand a temperature over 80 degrees C.

Throughput – higher welding speed

Weld speeds are generally higher with laser welding, especially with modern high power continuous wave (CW) fibre lasers.  A high welding speed sometimes means that the motion system, for example the CNC system or robot contouring speed, is the limiting factor on cycle time rather than the process.

Cost per metre of weld

In processes where throughput is high it is common to find that the laser solution is more efficient and results in a lower cost per metre of weld.   Interestingly, there are processes which combine laser and arc welding to achieve deeper penetration and higher welding speeds.  These hybrid processes typically use a combination of laser welding to heat the metal efficiently to melting point and arc welding to provide deposition of droplets into the weld pool and enhanced penetration and weld strength over either process as a stand-alone procedure.

No finishing of the weld

With inert gas shielding, a laser weld in stainless steel or aluminium normally requires no post-processing (grinding or dressing) after welding, the weld finish is bright and oxide free and can be typically coated or painted without further cleaning steps.

Access difficult areas

Since the laser beam is a “line of sight” process, the laser can pass through gaps in a structure to weld areas from the rear, where it would not be possible to introduce a TIG electrode.  Using a camera to view through the laser optics, it is easy to align the beam to a precise feature and perform welds in difficult-to-reach parts of the structure.

What about gaps?

One disadvantage of laser welding is that it tends to rely on good contact and minimum gap between parts to be joined.  With either a laser process or a TIG weld, there is a need to ensure that gaps are minimised or avoided to ensure good results.  With the addition of wire feed, which adds a certain complexity to the process, it is possible to fill gaps or build up areas for additional strength.

Conclusions

For ease of automation, consistent quality and lack of post-processing there are clear advantages to using laser welding.  Where welding is to be applied manually, TIG welding has greater flexibility and lower capital cost for the equipment.

robot laser cutting system

Business Minister Anna Soubry MP opens £60 million aerospace & 3D printing research facility at the MTC

Right Honourable Anna Soubry MP Business Minister opens £60 million aerospace & 3D printing cutting edge research facilities in Manufacturing Technology Centre Coventry to maintain the UK’s world leading position in aerospace.

The state of the art robotic laser system, designed and manufactured by Cyan Tec Systems, is specifically designed to have the ultimate flexibility, meaning that industrial organisations are able to prove a production process before committing to significant financial investment. The system incorporates an ABB six axis robot, two rotary manipulators and a 20kW laser, allowing the system to handle a range of different components as well as performing the required laser processes (cutting, welding, ablating etc.).

robot laser cutting system

The minister, pictured here with the cutting edge robotic laser system, incorporating the UK’s most powerful laser, announced the launch of a new £10 million competition to find game-changing aerospace technologies, aimed at small firms.

Managing Director Tony Jones states “Cyan Tec is proud be a supplier to the Manufacturing Technology Centre, showcasing advanced manufacturing capabilities, the Cyan Tec machine breaks new ground integrating a 20kW industrial laser to drive innovation in aerospace technology.”

Cyan Tec together with industrial businesses such as Rolls Royce & the UK government are working together to keep Britain at the forefront of the global aerospace market, the UK is second only to the United States in the valuable aerospace industry with demand for aircraft at record levels, roughly 45,000 new aircraft & 40,000 helicopters required in the next 17 years, generating opportunities totalling over $5 trillion.

Cyan Tec’s CEO, Clayton Sampson, reports “It is exciting to see government ministers taking an interest in our technology & we are pleased to be part of such a valuable initiative driving world class advances in the UK’s aerospace industry.”

Cyan Tec recognises the importance of this billion pound industry to the UK economy & is proud to contribute advanced technology equipment & services to this growing sector.

Cyan Tec welcomes the joint government & industry commitment of £2.1 billion for aerospace R&D to develop new high value technologies, improve aircraft factory production & the cost competitiveness of the UK supply chain.

robot laser marking cell

New Flexible Robotic Laser Marking Cell

In response to the demand from the automotive sector, Cyan Tec Systems have produced a new flexible laser marking cell using a 6-axis robot to carry a compact laser marking head for the marking of text and 2D matrix codes onto automotive engine components.  A compact solid state laser head fitted with a miniature 2 axis galvo scanner is carried on the end of the robot arm allowing the marking field of 120 x 120 mm to be positioned anywhere within the reach of the robot, and angled to suit the plane of the component surface which is to be marked.  The laser and robot are contained within a solid walled safety enclosure which protects the operator from the robot motion and the laser during the laser marking cycle.  Interlocked safety doors allow access to the robot for programming – a monitor is positioned externally to observe the operation of the cell from outside.

robot laser marking cell

Parts are automatically loaded and unloaded via a conveyor which passes through the laser safety enclosure of the cell.  A hand-held code reader is attached to the outside of the laser cell which allows the verification of codes on the incoming and outgoing parts.  The scanner is cordless and rechargeable – the data scanned is transmitted to the master cell controller via Bluetooth.

Laser marking is the most reliable, repeatable and rapid method of putting permanent high-contrast marks on the surface of virtually any material.   Laser marks resist wear and cleaning processes which means that traceability is guaranteed for the lifetime of the components.  Cyan Tec uses the latest in fibre lasers and diode-pumped solid state lasers from the leading manufacturers, which have the characteristics to mark rapidly and with very high definition.  Almost no maintenance is necessary meaning that uptime and throughput are maximised.  Cyan Tec can work with all the major manufacturers of robots and lasers to provide a solution compatible with the norms and preferences of the customer.

Flatbed laser cutter

Laser cutting of sheet metal: High speed, minimum footprint


New from Cyan Tec Systems is a flatbed cutting system for cutting metal sheets up to 8 mm thick and with sheet sizes of up to 2 m x 1 m.  This compact system is ideal for processing sheets which can be loaded by hand onto the extending front table.  Fitted with a 3kW fibre laser, this standard machine offers excellent value and takes up minimum floor space.

Read more

Flat Bed Laser Cutting Cell

The Hyperion-MG4-CF is the latest standard flatbed laser cutting cell from Cyan Tec.  Suited to the laser cutting of composite materials, including Carbon Fibre Reinforced Plastics (CFRP) and PEEK, the system uses a combination of galvo scanning and conventional high-speed CNC axes to cut at high speed without de-lamination of the material. Read more