OVERVIEW: The 304 stainless steel ammonia absorber and circulation tank experience temperatures of up to 100°C and an aggressive Chemical environment.
The prevention of stress corrosion pitting was achieved in the heat affected areas by applying corrosion protection on the entire internal surface.
INDUSTRY
ENVIRONMENT
Normal operating temperature is 60-70°C. Excursions up to 100°C are common.
• Wet ammonia gas
• Diluted sulphuric acid (up to about 20%)
• Ammonium sulphate
• Naphthalene
• Benzene
• Aromatic and aliphatic hydrocarbons
• Hydrogen sulphide
• Hydrogen cyanide
SUBSTRATE
304 Stainless Steel – Ammonia absorber and circulation tank
CHALLENGE
Prevent Stress Corrosion Pitting in the heat effected areas, these are generally found either side at the toe of the weld. Apply corrosion protection on the entire internal surfaces within a 72 hours outage
SOLUTION
Abrasive blast to Chemcote’s Specifications and 3 coats of Chem-tect™ RF 300 Series
SCOPE
Recommend the entire internal surfaces are treated
Mobilise on site
Set up of dust containment only
Set up of De-humidification equipment
Abrasive blast to Chemcote Standards
Application of a Chem-tect™ RF 300 in 3 coats including strip coat all difficult to reach areas
De-mobilise from site
PRODUCTS
Chem-tect™ RF 364 – vinyl ester / acrylic co-polymer enhanced with flaked glass; very suitable for immersed environments where superior resistance to chemical attack is required
OUTCOME
The best outcome the asset owner has obtained after years of trials using various epoxies and fibreglass linings. The combined large anchor profile achieved while abrasive blasting and excellent permeation resistance of the glass flake filler has proven itself again.
RELATED CASE STUDIES
Preventing blockages using Chemcote Solution
Condition of surface before mechanical preparation RB 364 applied to spot abrasive blasted surfaces Pugmill externals Coating with InD Cote Previous Next OVERVIEW: A
Base Plate Corrosion Prevention
Repairs required Application of Primer Coating applied to affected areas After application of Topcoat Previous Next OVERVIEW: A 40 year old excess gas bleeder structure
Industrial Fallout Protection
After whip abrasive blasting Application of Epo-chem system to internals Basalt Fibre application on internals OVERVIEW: A steel production plant contracted Chemcote to reinforce
