WHAT SHOULD BE ACID CLEANED?
- Scaled up Boilers
- Scaled up Pipework
- Scaled up Cooling Towers &
- Scaled up Heat Exchangers
WHY IS IT NEEDED?
- An acid wash is the only way of successfully removing scale.
- The buildup of scale in pipework, boilers or heat exchangers reduces the efficiency of the heating installation.
- Scaled up boilers are dangerous and will cause the boiler to fail inspection.
- Scaled up heat exchangers have reduced efficiency.
- Scaled pipework has reduced flow and increased pressure drop resulting in increased pumping costs.
WHEN SHOULD A SYSTEM BE ACID CLEANED?
Where boilers are involved, the boiler inspector will fail a boiler if it needs to be cleaned and the boiler will not be allowed back on line until it has been cleaned successfully. When a Cooling Tower is being inspected or dis-infected to prevent legionella disease, a scale build-up will be seen and an acid wash can be scheduled for the next shut down period. Heat Exchanges and Pipelines will become choked and flow will be restricted and pressure drop will increase across them when they require an acid clean, an acid wash should be done before flow through the system is blocked completely as flow is necessary to circulate the acid solution.
WHAT IS INVOLVED IN AN ACID WASH ?
An acid solution is circulated through a system.
A chemical reaction takes place and the lime is dissolved and removed from the system. During the acid washing other dirt and solids become loose and fall off the pipework; these are also removed by flushing and in some cases physically shovelled out of the system, for example in Boilers and Cooling Towers.