Hydroblasting Operations and Procedures
Domain focus
Hydroblasting Operations and Procedures covers the sequence of a job: permits and job safety analysis, setup, pressurization, lance work, and shutdown. Exam questions tend to focus on order of operations and on what to do when something abnormal happens.
Core rules
- Before pressurizing: permit and JSA complete, area barricaded, containment and drains in place, all fittings made up, nozzle secure, personnel clear, communication method agreed.
- Start with the pump in bypass or unload, then bring pressure up slowly while watching for leaks from a safe distance.
- Shutdown is a sequence: unload, stop the pump, dump pressure, bleed the lance and accumulator, verify zero, then lock out.
- Lance work: point the nozzle away from people and yourself, expect reaction force, never straddle a lance, and rely on a deadman that stops flow on release.
- Confined space and tube cleaning require atmospheric testing, an attendant, and a rescue plan before entry.
Worked example
A flexible lance stops advancing in a condenser tube while the pump runs at 15,000 psi. The wrong move is to raise pressure or push harder. Correct: unload, stop, bleed, verify zero, then withdraw the lance and inspect for a blocked nozzle or tube obstruction. Pressure trapped in a stalled lance turns the hose into a whip when the blockage clears.
Traps
"Cracking" a connection to check for flow; leaving the pump in bypass and assuming the job is safe; trusting a gauge at zero without a bleed; and restarting after a blockage without inspecting the nozzle.