Weld Testing Services to Ensure Top Results
You can be assured by knowing any task taken on for you involves in-house testing of all components to reach or exceed your corporate or the industry specifications. State-of-the-art helium leak detection machinery is used to test welds, and is annually serviced by the manufacturer as well as calibrated weekly and monthly by our team of certified experts to ensure it is operating at the highest standard. Helium testing is the preferred option for experts in the field, as helium is one of the lightest and smallest molecules and will find its way out of the most-miniscule leaks.
At Axenics, we rely on two main leak testing methods for your end components, pressure testing and vacuum testing. The proper method is determined based on the working conditions of the product being tested. The pressure conditions used during testing should reflect the conditions that will exist when your product is in use.
When performing pressure testing, the product is tested from the inside-out. First, the product is pressurized with helium (or a combination of helium and nitrogen). Then, each of the product’s potential leak sites are scanned with a Sniffer Probe, which is connected to the leak detector and will alert our team member to any confirmed leaks. Typically with pressure testing, the amount of pressure placed onto the product is higher than the product’s normal operating pressure. This is to ensure that if pressure gets unexpectedly higher, safety is maintained.
To confirm the integrity of your weldments, pressure testing is utilized. Pressure is applied to the weldment to determine what level of pressure it can withstand, and whether the joints will hold at the level of pressure required for the product to perform correctly.
A creep test is a pressure test variation used to locate component leaks. Creep, a.k.a. cold flow, is a slow deformation of materials due to time, temperature and tension. A creep test is one of the final steps of quality control in the welding process before the product arrives to the customer.
A creep test entails the blocking and sealing of tubing. Next, the technician pumps nitrogen into the tube. Nitrogen prevents moisture forming during the test, keeping metal from oxidizing. It’s also a preferred shielding gas for plastic creep tests. A gauge measures the PSI of the gas inside the component, and reconciles that with the customer’s specifications. A plastics creep test occurs at least 12 hours after welding, giving the weld 12 to 16 hours to cure. Then, a creep test for leaks takes place using the same method as metal creep testing.
On the flip side from pressure testing, is vacuum testing where the product is tested from the outside-in. First, the product is evacuated, and then helium is lightly sprayed onto a potential leak area. Helium that can be detected on the inside of the device, after the test is administered, confirms there is a leak. The product will need to be repaired or even discarded, depending on the intensity of the leak.
A weldment’s integrity can also be tested by using vacuum testing. The test involves creating a vacuum, as opposed to applying pressure. Then, the product is tested for leaks. We prefer this method to ensure the integrity of weldments created for you.
The skill and training for ultrasonic NDT is more extensive than other NDT methods, and is overseen by our quality control department. Ultrasonic beams are safe for testers since they do not contain electromagnetic radiation. Ultrasonic testing locates the exact position of a weld discontinuity more accurately than even radiographic testing.
We establish a weld’s internal integrity with ultrasonic testing with the following process:
- An ultrasonic gauge transmits a beam of high-frequency ultrasonic energy into the component or material.
- The ultrasonic beam penetrates the entirety of the component or material.
- Then, two audible signals result from the gauge, alerting the tester.
- If the ultrasonic beam intercepts a discontinuity in the component, it reflects the location back to its point of origin and a third audible signal sounds.
- This indicates there is a deformity beyond acceptable parameters. From that signal, we know the exact location and size of the deformity.
Other testing methods we can use for your products include:
Hi Pot Electrical Testing
We’re certified to perform this electrical test, which is used to ensure your product is properly grounded.
This is used to determine the strength of a weld. The test involves physically pulling joined materials apart, and measuring at which point, in pounds per square inch, the weld separates.
This test is used to determine if there are voids or cracks in a weld, and to measure the overall strength of a weld.
Why use helium for leak detection?
Helium leak detection is the best way to check for leaks because helium is one of the lightest and smallest molecules and will find its way out of the most miniscule of leaks.
Only hydrogen has a smaller or lighter molecule weight, but it is flammable and more expensive and, thus, not the ideal option for this type of testing. Helium is nontoxic, inert, inflammable and non-reactive, making it safe to use. It is also easily detectable and can be monitored to determine any deterioration that may occur over time.
Testing is an integral part of every project we complete for our customers. Testing procedures begin the moment a delivery of raw materials arrives on our shop floor and conclude when your components are safely shipped.