NON-ENTRY TANK CLEANING IN NEW-ZEALAND & AUSTRALIA
SteamTech provides non-entry tank cleaning for crude oil, condensate, petrol and diesel storage tanks in New Zealand & Australia. Our remotely operated robotic equipment removes typically 90 to 95% of the sludge and residues from outside the tank, and in many cases 100%, depending on the tank’s drainage system. It also brings the tank to a condition where entry can be safely carried out. Where a detailed clean is required, our trained confined space team completes it by hand. On some tanks, no entry is needed at all.
Our largest robotic clean to date is a 60 m diameter crude oil storage tank. No one enters the tank while it has a hazardous atmosphere. That is the stage of tank cleaning with the highest risk of oxygen-deficient, flammable and toxic atmospheres, and the hardest conditions for rescue. Removing that stage from manual work is the core safety benefit of robotic cleaning.
HOW NON-ENTRY TANK CLEANING WORKS
- Planning with the client : We review the tank's product history, deposits, manway positions, roof type, internal structures, isolation requirements and waste handling, and prepare a full written inerting and cleaning procedure for the tank, which the client reviews and signs off before work begins
- Isolation and inerting : The tank is isolated and, where required, inerted with nitrogen to keep the oxygen level below that needed for combustion.
- Remote cleaning from outside the tank : Robotic manway cannons rated for Zone 1 hazardous areas are mounted at the manways and operated from outside. A hazardous-area-rated camera and lighting on each cannon give the operator a live view inside the tank throughout the clean.
- Continuous atmospheric monitoring : The tank atmosphere is monitored continuously. If oxygen rises above the set limit, the equipment shuts down automatically, this is a critical control.
- Recovery and recycling : Sludge, residues and wash water are pumped out to holding tanks. Wash water is recycled where suitable to reduce the volume of wastewater produced.
- Making the tank safe for entry : Once the robotic clean is complete, a nitrogen-inerted tank is returned to a normal atmosphere. The tank is then ventilated, and the atmosphere is tested by both SteamTech and the client before anyone enters. All entry is carried out under the client’s permit to work system.
- Detailed clean, if required : Where the tank needs a detailed clean for inspection, maintenance or a change of product, our trained confined space team carries it out by hand, under permit, with gas testing and continuous air changes. On some tanks the robotic clean is sufficient and no entry is required.
OUR CAPABILITIES
- Storage tanks from 3 m to 60 m in diameter, most commonly 16 m to 30 m. Our largest robotic clean to date is a 60 m diameter crude oil storage tank.
- Robotic cleaning typically removes 90 to 95% of sludge, and in many cases 100%, depending on the tank’s drainage system.
- Fixed roof and internal floating roof tanks.
- Crude oil, crude oil sludge, condensate, petrol and diesel.
- Robotic manway cannons rated for Zone 1 hazardous areas, with hazardous-area-rated cameras and lighting.
- 3D rotary cleaning heads for tanks up to 15 m in diameter.
- Cold or hot water cleaning, with detergents where required, selected to suit the product, deposits and tank condition.
- Nitrogen inerting with continuous oxygen monitoring and automatic shutdown.
- Bonding and earthing of equipment to control static ignition risk.
- Wash-water recycling to reduce wastewater and the waste footprint.
OUR CLEANING AND DECONTAMINATION METHODS
SteamTech designs a cleaning process for each job, based on the product being removed, its volatility, the deposits present and the condition of the tank or plant. Our methods include:
- Non-entry tank cleaning using remotely operated robotic manway cannons (see the priority page above).
- 3D rotary head cleaning for tanks up to 15 m in diameter.
- Cold and hot water cleaning, with detergents where required, selected to suit the product and deposits.
- Steam cleaning and steam decontamination of tanks, vessels and process plant.
- Flushing and circulation cleaning, with pumping of wash water, sludge and residues.
- Nitrogen purging and inerting, as a standalone service and in support of tank cleaning, for storage tanks, process equipment and geothermal applications.
- Wash-water recycling to reduce wastewater volumes.
Tanks are cleaned for inspection, maintenance or a change of product. Robotic cleaning removes the majority of sludge and makes the tank safe for entry; where a detailed clean is required, our trained confined space team completes it by hand.
HYDROCARBONS AND CONTAMINANTS WE HANDLED
SteamTech has removed the following products and residues:
| Category | Products and Residues |
|---|---|
| Hydrocarbons | Crude oil, crude oil sludge, condensate, petrol, diesel |
| Industrial residues | Coal tar residues, removed from a steelworks gas holder in Wollongong, Australia |
| Food processing | Food residues, tallow, cooking oils, milk residues |
Each cleaning process is designed around the material being removed and its volatility.
OUR EQUIPMENT AND TECHNOLOGY
Tank cleaning equipment
- Robotic manway cannon system, rated for Zone 1 hazardous areas, operated remotely from outside the tank, with hazardous-area-rated cameras and lighting.
- Specialized pumping equipment with rotary cleaning heads, including 3D heads for tanks up to 15 m in diameter.
- Hot water blaster units.
- Oxygen monitoring equipment for inerted cleaning, with automatic shutdown interlocks.
- Breathing apparatus and a rescue trailer, supported by trained confined space entry and rescue personnel.
Steam and hot water boilers
SteamTech operates a fleet of six steam boilers for steam decontamination of plant, steaming of vessels and tanks, bitumen heating, and temporary steam boiler hire. The boilers operate at 10 bar and are inspected and certified annually.
| Quantity | Rated Output | Steam Output at 10 bar | Combined Steam |
|---|---|---|---|
| 4 | 0.49 MW (490 kW) each | 680 kg/h each | 2,720 kg/h |
| 1 | 1.47 MW (1,470 kW) | 2,450 kg/h | 2,450 kg/h |
| 1 | 1.96 MW (1,960 kW) | 3,100 kg/h | 3,100 kg/h |
| 6 boilers | Total fleet | 8,270 kg/h | |
Sizes and operating capacities
SteamTech operates a fleet of six steam boilers for steam decontamination of plant, steaming of vessels and tanks, bitumen heating, and temporary steam boiler hire. The boilers operate at 10 bar and are inspected and certified annually. SteamTech cleans storage tanks from 3 m to 60 m in diameter.
The most common sizes we clean are 16 m to 30 m in diameter, and our largest robotic clean is a 60 m diameter crude oil storage tank. Our 3D rotary cleaning heads suit tanks up to 15 m in diameter, and our robotic manway system has been used on tanks up to 60 m. Whether a tank suits a particular method depends on its diameter, manway positions, roof clearance, internal structures, deposit characteristics and the waste extraction arrangements.
Our steam boiler fleet of six units produces from 680 kg/h to 3,100 kg/h each at 10 bar, with a combined output of 8,270 kg/h. Hire tanks range from 19 m³ to 65 m³.