The Technology of Waterjetting/Waterblasting is defined by the specialized, precision equipment which directs high pressure (10,000+ psi) streams of water against a surface to clean, prepare, cut or demolish the material. The use of plain water under pressure makes this technology environmentally friendly without "heat or chemical zones" which can damage surrounding equipment and structures.
The waterblasting high pressure equipment (pumping units), in combination with accessories (waterblasting guns, scrubbers, nozzles, rotary hoses, etc.) which focus the water stream and control pressure levels, define each Hydrocleaning and Hydrodemolition application:
♦ Hydrocleaning, high pressure cleaning or waterblasting is the use of water propelled at high speeds to clean surfaces and materials and prepare hard surfaces for coatings.
♦ Hydrodemolition (also known as hydro demolition, hydroblasting, hydro blasting, hydromilling, waterblasting, and waterjetting) is a concrete removal technique which utilizes high-pressure water to remove deteriorated and sound concrete as well as asphalt and grout.
In order to standardize cleaning operations and surface preparation specifications the Steel Structures Painting Council (SSPC) has adopted the following four definitions for using water jetting technology:
♦ Low-pressure water cleaning (LP WC) is the use of water pressure less than 5,000 psi (34 MPa).
♦ High-pressure water cleaning (HP WC) is the use of water pressure between 5,000 to 10,000 psi (34 to 70 MPa) most commonly utilized in cleaning and surface preparation.
♦ High-pressure water jetting (HP WJ) is the use of water pressure between 10,000 to 25,000 psi (70 to 170 MPa) most commonly utilized in cleaning, surface preparation and scarification (partial depth removal).
♦ Ultrahigh-pressure water jetting is the use of pressures above 25,000 (170 MPa) most commonly utilized in cleaning, surface preparation, scarification (partial depth removal) and hydrodemolition (full depth removal).
Any process that is powerful enough to cut concrete can cut skin and bone. Operators of hydrodemolition equipment are required to wear many types of protective equipment.
For robotic hydrodemolition equipment, the operator wears steel-toed boots, eye protection, earmuffs and hard hat. Hand lance operators wear steel-toed boots, metatarsals, shin guards and sometimes body armor.