Sapesco have for decades, offered the client many options for cleaning process system equipment and pipelines in the oil, gas and petrochemical sectors. These systems fall into three main categories: -
- Chemical cleaning, where a solvent system is recommended for degreasing operations and the removal of mill scales, corrosion, paraffin waxes, other contaminants and hydrates etc.
- Mechanical cleaning where physical intervention is required with tools that are designed to make contact with contaminants and provide a means of removal.
- Water jetting, ultra high pressure jetting, water jetting with abrasives and retro-jetting of pipe sections are used to achieve the desired level of finish.
Chemical Cleaning
The question of the necessity of chemical cleaning is rarely asked. International standards determine cleanliness levels; international manufacturers determine initial condition standards for commissioning; maintenance personnel determine frequency of cleaning. Questions raised are normally concerned with the technique to be applied for given conditions. The application of Chemical Cleaning to particular Topsides, Pipeline and Process Systems equipment is a tried and tested method applied to:
- Avoid lengthy start-ups and delays.
- Reduce waste of raw materials and feed stocks.
- Reduce waste of production utilities (steam, water)
- Produce products, which can be sold immediately on the open market.
- Conserve energy use.
- Prevent equipment damage and losses.
- Increase time between maintenance shutdowns.
Any of the above items can be singled out and the individual values calculated in financial terms. Money saved could pay for the chemical cleaning. For example, inefficient fuel consumption due to poor heat transfers can be measured in hard currency and the replacement of new compressor internal parts, caused by inadequate steam delivery, costs not only time but a significant amount of money.
SAPESCO provides both operational and pre-operational chemical cleaning.
Cleaning services are provided for almost all of the equipment in industry, which is subject to mineral scale formation / oxidation during operation:
- Refinery Equipment
- Gas Plants
- Petrochemical Complex Equipment
- Steel and Paper Mills
- Steam Generators and Power Plants.
SAPESCO applies various cleaning methods to achieve successful and cost effective cleaning results such as, solvent circulation, soaking, cascading, vapour phase, and foam cleaning, to name just a few. A typical generic Chemical Cleaning Procedure could be as follows:
- WATER FLUSH
This is done to remove the loose scale and debris. - DEGREASING
This removes oil and grease from the inner surfaces of the system. - DESCALING
This stage is the heart of chemical cleaning operation in which the scale is removed from the inner surface of the process equipment subjected to the cleaning operation. - PASSIVATION
The process is used to convert the inner surface from a highly active state, after the scale removal, into an inert state, to resist further short-term corrosion possibilities.
PRESERVATION
During this process, the system can be filled with a suitable preservation material for long-term protection.
The above procedure is just a sample of a commonly used practice. Each job is engineered according to the application, thus procedures alter according to the system parameters and the solutions used will vary with client specific requirements.
It should be noted that a Chemical Cleaning solution is available for almost every perceivable operations cleaning requirement. The treatment processes of chemical cleaning can be applied to pipelines, process systems and vessels.
Many alternative processes are available for the removal of contaminants and wax derivatives.
Mechanical Cleaning
Mechanical Cleaning systems employ tools that physically make contact with the contaminants to be removed. In the case of heat exchanger bundles, for example, where no flow path exists, a centralised drilling system can be used to bore out the offending material. Similarly, abrasive rods, reamers and grit systems can be employed to return reduced flow systems back to specification values. Mechanical cleaning is not restricted to operations on process plant. Pipeline transport lines can be cleaned using a variety of pipeline cleaning tools. These include, but are not limited to: -
- Pin Wheel Pigs
- Carborundum Pigs
- Wire Brush Pigs
- Plough Pigs
- Scraper Pigs
- Jetting Pigs
- Combination Cleaning Pigs (inc articulated Go-Devils)
Combination Cleaning
A combination of water / solvent canons and robotic cleaners can also be employed for tank cleaning etc, bringing together the best of mechanical and fluid treatment systems.
High Pressure Water Cleaning
SAPESCO applies a high level of technology for the high-pressure water cleaning of equipment and lines. This is an area where chemical cleaning would not be a cost effective method to achieve a high degree of cleaning. In addition, the process is a more safe operation for both SAPESCO personnel and client equipment.
Sapesco equipment is subject to a very tight quality assurance program, prior to being put into operation, to ensure safe operating conditions for personnel and equipment.
Below is a list of some of the high-pressure water cleaning services and equipment: -
- Jet Mole - used in pipelines to remove extremely stubborn scale.
- Shot Guns - short hand lances used to blast away deposits from tube sheets, pipe and tube exteriors.
- Automated lancing - uses stiff lances and indexers to clean exchangers more quickly and more safe than hand lance operations.
- Bundle blaster - moves water in large volumes to blast deposits from heat-exchanger bundles, both inside and out.
- Rotojet services - automated three-dimensional cleaning of vessels, providing improved speed and safety.
- Bio-blast services - safely removes virtually any coating or residue from even the most delicate surfaces without endangering workers or the environment.
- Chem-blast services – three-dimensional cleaning in vessels. This service, when combined with Rotojet services, provides SA2 bright metal finish to vessel walls. Uncoated vessel walls can be cleaned with Ph Neutral solvents. Coated vessel walls receive multi-stage treatments.
- UHP services - ultra high-pressure water blasting with pressures ranging up to 45,000 psi for extremely difficult deposits.
- Metal cutting services - uses high pressure blasting to cut metal safely without harming the base material.