Adhering to H Grade Requirements and its Alternatives
Special considerations must be taken into account when operating temperatures exceed 1000°F [540°C]. In these instances, ASTM A240 specifies the use of “H grade” alloys (i.e. 304H, 316H, 321H) for ASME applications. H grades have a higher carbon content than the standard and L grades of their corresponding alloys which ensures increased strength at elevated temperatures. They must also have a grain size of ASTM No. 7 or something even more coarse. There are alternatives to H grade, namely Inconel 625 that is better suited for higher temperatures.
Avoid Stress Cracking from High Velocity Flow
Penflex Director of Quality and Engineering Janet Ellison discusses two approaches to avoid stress cracking caused by high velocity flow through a metal hose assembly.
Basics of Hose Geometry
What makes metal hose flexible? Penflex Director of Quality and Engineering Janet Ellison breaks it down for us.
Common Causes of Hose Assembly Failure
Penflex’s hose assembly field inspection checklist helps identify the nine most common causes of hose assembly failure.
Helium Mass Spectrometer Testing
First developed as part of the Manhattan Project during World War II, mass spectrometer testing relies on a sealed vacuum chamber filled with helium. As helium leaks out of the chamber, the mass spectrometer machine detects the leak rate. Penflex uses helium mass spectrometer testing for hose assemblies with applications in, for example, the cryogenic industry.
Impact of Operating Conditions on Hose Flexibility
Penflex Director of Quality and Engineering Janet Ellison discusses further considerations, beyond hose geometry, for assessing a hose’s flexibility.
Leak Detection Methods for Hose Assemblies
Submersion bubble leak and hydrostatic tests are the two most common methods of testing metal hose assemblies for leaks. Penflex will often use one or both of these methods, or—if the molecules of media being transferred are smaller than air—we will use a mass spectrometer to test the assembly.
Meet the Inside Sales Team!
You’ve talked with them on the phone and exchanged countless emails…now put faces to their names. Meet Kerri Hartzell and Andrea Tokarski who make up our Inside Sales Team at Penflex!
Penflex Mechanical Forming Processes
At Penflex, we use a split die mechanical forming process for our 700, 800, 900 and 1400 Series in sizes ¼” to 2” while all sizes of the P3 and P4 Series use a rotating die mechanical forming process. The benefits of these mechanical forming process include the ability to form heavy wall materials—such as Hastelloy and Inconel—that will have a longer life and higher working and burst pressures than thinner walled hoses in similar applications.
Penflex Welder Training Program
Our one-week ASME Sec. IX-certified program for welders with mid-level experience is designed to improve technique. We’ll take them through all the pipe welding requirements for attachment welds, butt welds and pipe welding and then go into the basics of hose manufacturing and metal hose assembly building. Welders will build their own assemblies starting with Penflex 2″ P3 and moving down to 1/4″ P3, one of the most difficult pieces of hose to weld. They’ll learn purging as well and we’re confident they’ll leave our program a lot better than when they came in.
Stress Corrosion Cracking: Causes and Prevention
Stress corrosion cracking, or SCC, can lead to failure in piping systems, pressure vessels and highly stressed components. It occurs when there is a susceptible material experiencing working or residual stress above the SCC threshold in a corrosive environment.