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Interchange and intermix are two words that sound like they might mean the same thing. However, while they do have some similarities, they are not the same. Below, we will discuss their difference and how Superlok fittings can be used in partnership with other brands that may already be in your system or spare parts cabinet.
Interchange
Interchangeability among tube fittings is when one fitting from "Brand A" is designed to fully replace a similar fitting from "Brand B".
An example of this is the Superlok SMCI-6-4N and the Hoke Gyrolok 6CM4-316. Though these fittings do not share identical operation dynamics, both of these fittings have a 3/8" tube compression end and a 1/4" Male NPT threaded end. They are also rated for the same operating pressure and tubing compatibility.
In this instance, the fittings would be "interchangeable" as you could swap the Hoke fitting for a Superlok fitting and they would perform the same duties.
Intermix
Intermixability in the tube fitting market is a little more nuanced than interchangeability. When parts are said to be intermixable, it means that even their smaller components can be swapped in and out of either system without compromising the capability of the system.
An example of intermixability would be the Superlok SMCI-6-4N and the Swagelok SS-600-1-4. Both fittings are more than simply supliments for eachother. As stated above, these two parts can share internal components. If you were to fully disassemble both fittings and leave all the parts in a jumble on the bench, any combination of the components would make a complete and capable fitting once assembled.
Superlok Intermixability
While we cannot speak for other fitting manufacturers, Superlok has conducted extensive testing with fitting components from other brands intermixed with Superlok components. We stand behind the testing of the below fittings as intemixable with Superlok tube fittings.
Double Ferrule
- Swagelok
- Parker A-lok
- DK-Lok
- Hy-Lok
Single Ferrule
- Parker CPI
- DK-Lok
- Hy-Lok
Limitations to Intermixability
With all intercompatibility there are bound to be slight variances to overcome. In the case of Superlok, the only part of the system that does not intermix is the i-Fitting built-in gap gauge. This system relies on having the correct geometry on the bottom of the compression nut to engage with the red ring. With other brands of compression nuts, this system could prove to be inaccurate as they may break the ring too early or too late.
What Prevents Interchangeable parts from being Intermixable?
A major problem that prevents intermixability of certain fitting brands is any significant deviation from the original fitting spec. These are commonly done in the name of improving the standard, but often result in components that do not mesh with other brands.
An example of a non-intermixable fitting would be the above mentioned Hoke Gyrolok. These fittings include a positive stop point on the ferrule itself designed to prevent over-tightening. However, because of this design change, the ferrules are a different shape and the fitting bodies do not have the geometry needed for a gap gauge measurement.
These types of fittings can be dangerous if allowed to occupy the same spare parts bin as other standard fittings. If a worker were to collect the wrong parts and attempt to rebuild a connection, the parts would likely not connect correctly. This could lead to leaks, improper installations, and possible catastrophic rapid unintended disassembly.
