Torr gauge for measuring a vacuum.

Torr Gauge – Click to enlarge.

We often get asked where did we get the name TORR Engineering. So just to clear it up, we’re not TOUR Engineering or TORE Engineering or even THOR Engineeirng, we are TORR, named after a unit of pressure that is used to measure the depth of a vacuum.

The unit was named after Evangelista Torricelli, an Italian physicist and mathematician who discovered the principle of the barometer in 1644. 1 Torr is equivalent to 1/760th of atmospheric pressure.

We introduce a vacuum, by way of a vacuum pump, to the sealed network of refrigeration / air conditioning pipework for two reasons.

Firstly to remove any air and other non condensable gases (NCG’s) from the system. The other equally important purpose is the removal of moisture.

Vacuum pump for refrigeration & air conditioning.

Vacuum pump – Click to enlarge.

We measure the depth of this vacuum with a TORR gauge. The ‘perfect’ vacuum of 0 Torr is physically unobtainable, so we aim for 2.
Once we achieve 2 Torr we turn off the vacuum pump and monitor the gauge. If the gauge rises rapidly to 10 and above, this indicates the system has a leak.

We would always pressure strength and leak test a system with oxygen free nitrogen before vacuuming, so this is rare but a welcomed backup indication of a leak.

If the gauge rises slowly or slightly by 1 or 2 Torr it indicates there is still moisture present in the system and further vacuuming is needed.

Once we can turn off the vacuum pump and the gauge does not move above 2 Torr we know we have our perfect vacuum…

…As well as our perfect name.