New VariQtire Tire Pressure Control System From IWN: Two-wire Technology with Only One Line
(Author: Hubert Wilmer / Profi)

IWN's new VariQtire tire pressure control system not only has internal rotary transmitters, but also offers the safety of a two-wire system with just one line.
Basically, there are two different systems for adjusting the tire pressure (box: “This is how single-wire and two-wire systems differ”). IWN has now succeeded in combining the advantages of the two-wire system with those of the single-wire system.
At the heart of the development is a valve unit on each wheel that has it all. If it is ventilated via the supply hose at less than 3 bar, it opens the wheel valve and air can escape from the tire. If the pressure in the feed line is increased to over 5 bar, pistons in the valve unit switch over. The air can no longer escape from the wheel, but the tire is inflated. It's brilliant, but for patent reasons we can't show more.

This is how single-wire and two-wire systems differ.

In single-wire systems, no valve has been switched on the wheel itself up to now, which is why the lines and rotary transmitter are always under pressure. If the cable is routed to the wheel from the outside and a rotary transmitter with a small radius can be used, this technology is simple, inexpensive and proven.

Disadvantage: If the system has a small leak, you have to manually close the ball valves on the wheels – at least overnight – to avoid having a flat tire in the morning. In addition, of course, the lines protrude beyond the vehicle outlines from the outside, which can interfere with silo rolls, for example.

In the two-wire system, a second line leads to each wheel to open a valve on the tire. Air can be inflated or deflated via the main line. Advantage: The lines are usually unpressurized so that the reduced wear allows large-diameter internal rotary transmitters. In addition, there is no problem with pressure loss in the tires, either when the hose breaks or when there are small leaks. The disadvantage of two-wire systems is the higher cost of double hosing including rotary transmitters and the additional valves in the wheels.

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https://www.profi.de/technisch/neue-reifendruckregelanlage-variqtire-von-iwn-zwei-leiter-technik-mit-nur-einer-30073.html