Now we don’t often try to poke holes into the competition, but when they do it themselves… it is worth noting.

Much, if not all, the industry uses a refrigerant transport hose for evacuation. While some of the larger diameter hoses offer scant advantages such as higher conductance speeds – they were never intended or designed for deep vacuum or evacuation.

A refrigerant transport hose is multi-layered, intended and rated for pressure. The materials used are in many cases gas permeable which requires venting of the outer hose-layers to prevent bubbling and bursting under pressure. If you closely inspect these “vacuum rated” hoses you will see holes pricked about an inch apart throughout the entire length. This is called Hose Pin Pricking.

“Pin-pricking a hose cover permits trapped gases or vapours to escape from the hose carcass. Steam, air, and other gaseous products can permeate (pass slowly) through the tube and will build up in the reinforcement area – so the manufacturer must “pin-prick” the cover on certain hoses” New Line, What Does Pin-Pricked Hose Cover Mean?,, last accessed August 2nd, 2018.

Like holes, permeability is a two-way thing. This is because a hole is not a check valve. Now it is important to realize that these holes are not through holes, that is they only pierce the outer layer.  However, the sheer necessity reveals a lot about the materials from which these hoses are made and gives us some insight as to why they do not perform very well in a deep vacuum.

In vacuum speak, conductance speed is where it’s at.  Large diameter hoses provide higher conductance speeds which remove atmosphere many times faster than skinny hoses. Larger diameter hoses result in lower friction. But while bigger is better, that is only part of the equation.

Vacuum is a two-part process, degassing and dehydration. While a large gas permeable hose might get the bulk of the atmosphere out quickly, it will not perform as well in a deep vacuum. Not being able to achieve a deep vacuum means limited or slower moisture removal. As the liquid line dryer has a limited capacity, getting as much moisture out of the system as possible is critical.

Copper Plating From Improper Evacuation

Because moisture removal is the most important step in the evacuation, it is not a step that should be taken lightly or overlooked. Air or noncondensables will simply cause issues with performance. If you were to introduce nitrogen into a system, for example, it would drive up the head pressure and lower the efficiency, but it likely would not cause any damage to the system or its components. 

Moisture, on the other hand, is a different story. Moisture combines with refrigerant causing hydrofluoric and hydrochloric acids as well as other compounds like sludge that will irreversibly damage the equipment.

That brings us to an engineered solution. When designing TruBlu it became apparent that no other vacuum related industry used transport hose for evacuation, and one could only wonder why. The reason is simple; it just does not work very well for deep vacuum. If you own a “vacuum rated” hose test it against the TruBlu and experience the difference.

Sorry in advance to those left wondering how that nice black 20-micron rated hose cannot seem to achieve 20 microns.

Is there a “hole” in that theory? It’s up to you to test for yourself. Simply attach the vacuum gauge to the end of each hose one at a time and see how deep they pull. The difference will be obvious.

TruBlu uses technology from the scientific and industrial vacuum communities where deep vacuum matters, and evacuation time is often one of the most critical requirements. Process evacuation is all about moving product down the line, and not having it come back due to improper or insufficient evacuation.

With TruBlu you get it all. Not only is TruBlu bigger and faster with initial pulldown, but it is also significantly faster at removing moisture, achieving deeper vacuums, and ultimately, dryer systems.

If you are using “transport hose” for evacuation, it is time for an upgrade! If you are using transport hose in parallel with TruBlu hoses, expect a drop in overall performance. A vacuum rig is only as good as its weakest link. While you will see a significant increase in speed due to conductance gains with the TruBlu hose, a refrigerant transport hose will permeate enough to significantly impact ultimate vacuum, likely to the tune of 100 microns or more!  Not only will it save you a ton of time, systems will last longer and run better. Not to be a “prick” that, my friend, is a fact.