"Pressure Irons"
Are the domestic versions of commercial steam boiler irons.
There are two basic models:
One gets steam from a true steam boiler, though the boiler is small, it none the less is boiler. Such an system requires setting up and installing by a qualified person.
The other are industrial versions of the Rowenta and other models. These are designed for "light" commercial use such as drop stores and perhaps seamstresses/tailors who do not a constant supply of steam all day.
Had an Italian made steam boiler system, but the boiler finally went and got rid of the thing, but kept the iron.
Beauty of the commercial steam boiler systems (Reimers and Sussman were big in this area), is they produce true "dry" steam, much like what one gets from a steam boiler system. Though cannot remember what PSI indicates dry steam, it does wonders with pressing,ironing and the like.
Vacuum Tables,
Again, systems such as the Rowenta, Laura Starr, and the like are domestic versions of systems used in commercial laundries and dry cleaners.
Steam boiler irons, and to a lesser extent gravity irons produce so much steam that it quickly overwhelms standard ironing boards, especially when doing many items in sucession. The padding becomes wet with moisture and that excess moisture wicks bac, up to the garments, slowing down the ironing process.
Vacuum tables/ironing boards pull the steam through the garment and exhaust it out elsewhere. This drys and sets whatever is being ironed much faster, and again is a boon when using the amount of steam generated by boilers and generator systems. Because the item is dried not by relying on evaporation only, one's ironing tends to look neater and more professional, then when steam ironing alone.
Many vacuum ironing boards also contain built in heaters to keep the padding and cover dry, again this is done to cope with all the steam generated by high steam ironing systems.
L.