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Author: Chemcote

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Blast Furnace Recovery Turbine Repairs

Industry

Steel Manufacturing

Date

2006 – 2020

Substrate

Steel outlet and inlet spools, flange faces, shut off valves, turbine casing components and manway covers

Products

Epo-chem™ RL 500PF externally

Chem-tect™ RB 364 to coat internals

Epo-Chem™ RW 500 for spot repairs

Reinforcement using Kevlar

Spot repairs using Ind-Cote on struts

Environment

Wet blast furnace gas, from 20-40°C

Challenge                  

Overhaul was coordinated and planned for completion of some components in Chemcote’s workshop

On site work was carried out by setting up appropriate containment and navigating difficult to access areas to achieve thorough cleaning and surface preparation

Chemcote’s Solution

Apply Chem-tect RB 364 series to internals of the pipework and casings in 2 coats where possible.

This glassflake filled vinyl ester has proven to be most suitable for applications where good corrosion resistance and excellent mechanical properties are required.

Set up of Containment

Masking Before Blasting
Spool Condition Before Coating
Arial view of Outlet Spool from Shut off Valve
Completed Outlet Spool Internals
Application of final wrapping layers on legs
Internal and external coating complete
Coated and ready for reassembly on site
Coated and ready for reassembly on site
Ready to be reinstalled on site

Scope                      

Full treatment where required;

Pressure wash, abrasive blast internals and externals

Full abrasive blasting was carried out on internals on site for full refurbishment 

Seal redundant holes and split ring using polyurethane.

mechanical preparation and small touch up repair.

Results                

Chemcote has successfully reduced long term maintenance costs by carrying out intermittent inspections and documenting recommendations for coating systems used over the 14year service duty

Long Term Protection Of ISOtainers

Sodium Hypochlorite storage solutions provided by Chemcote Specialty Coating Australia

Industry

Chemical Production

Date

March 2012

Substrate

New 304 Stainless Steel

Products

Chem-tect™ RC 300

Chem-tect™ RA 364 glass flake reinforced vinyl ester

Environment

13-15% Sodium Hypochlorite

Challenge

Asset owner required internal protection for their new ISOtainers which would be carrying sodium hypochlorite

Solution

Abrasive blast and remove abrasive material.

Application of RC 300 by spray application and stripe coating of all welds with a nominal thickness of 1,000μm

Confirm thickness and spark test

Apply top coat and post cure at 60degC for 6 hours

Newly fabricated sodium hypochlorite tank
Newly fabricated tank internals

Internals of sodium hypochlorite tank
Tank Internals
Confined space entry to sodium hypochlorite tank
Confined space entry
sodium hypochlorite loading onto truck
Completed tanks for delivery to customer

Results                

The success of this project has allowed the asset owner long term peace of mind for their investment.

Floating Restaurant Structure Repairs Using Underwater Curing Epoxies

Industry

Marine

Date

October 2017

Substrate

Steel Brackets

Epo-chem™ RS 500P a surface and moisture tolerant primer

Epo-chem™ RA 500M a glass flake filled epoxy

Environment

Seawater

Challenge                  

The use of underwater curing epoxies were the most practical solution for this project. In the complete refurbishment of the underside of this floating structure some areas were replaced. Others areas required repairs to be done in-situ by using underwater curing epoxies. A team of experienced divers applied the underwater curing epoxy coating.

Chemcote’s Solution

Chemcote’s surface tolerant Epo chem™ system is able to provide full coverage to surfaces where ideal surface preparation cannot be achieved

Condition after application of 2nd coat

After application of second coat
After application of second coat
Final Application

Scope                      

Repairs were carried out at low tide where possible. Fresh water washing sections provide suitable surface preparation before applying the underwater curing epoxies.

Removal of large, flaking corroded areas and coating back to bare steel by mechanical preparation using pneumatic needle gun, air chisel, scabbling and bristle blaster

Preparation underwater to St 2 by using an underwater grinder
Primer applied to create a continuous coating without pinholes wearing gloves and application mitts.

Product was lathered on in small, workable sections and cured overnight

The next day at low tide, the repair area above the surface was washed with fresh water, then RA 500M, glass flake filled topcoat was applied to above and below water sections

Results                

By coating with Epo chem™, follow up inspections indicate the coating and repairs are still in good condition, and is expected to exceed 10 years life in service

Relining of Open Top Quench Tank

Industry

Steel Manufacturing

Date

May 2019

Substrate

30 Year Old Heavily Pitted Steel

Products                    Chem-tect™ RB 300 Series, a glass flake filled

vinyl-ester

Environment              Mildly acidic water ranging between 50-70°C

Challenge                   It was too late for some areas requiring replacement and repair of wall plate and internal pedestals supporting the rolls requiring replacement. Removal of the tank wasn’t feasible and an insitu cost effective repair method was required. With live crane rails, great heights and the centre of an active production area to contend with Chemcote came to the rescue.

Chemcote’s Solution Prefabricated items to be coated before installation to reduce application time on site to particularly on difficult to reach areas

Condition before abrasive blasting
Containment set up to prevent dust
emissions
Removal of garnet after abrasive blasting
First Coat Spray applied

Scope                         Removal of heavy corrosion and scale by needle gunning, scabbling and chiselling exposed the condition of the substrate beneath all of the scale and build up, locating holes through the plate and very thin areas requiring unplanned fabrication repairs. New supports and a weir plate were welded into place, in addition to penetrated weld seams allowing moisture to permeate. Abrasive blast was carried out to class 2.5

Composite repair techniques and pit filling were used to achieve structural integrity on damaged areas

Application of RB300 Series to a nominal thickness of 400µm total DFT

Holiday testing at 12kV was carried out

Results                       By coating with Chem-tect™ RB 300 will provide an excellent corrosion barrier, expected to exceed 20 years life in service

Chemical Storage Tank Relining

 

Industry                     

Chemical

Date

May 2019

Substrate

Chemical Storage Tank – Mild Steel, with external Cladding

Products

Epo-Chem™ RS 500P, a surface and moisture tolerant epoxy MIO primer

Epo-Chem™ RA 500M moisture tolerant glass flake filled epoxy topcoat, designed for immersed applications

Environment

Sulphonic Acid Storage at 50° C

Challenge

Existing epoxy lining on this chemical storage tank was in poor condition, with large sections experiencing deterioration alongside staining and corrosion of the tank wall. This stained the finish product preventing use until a long term solution was found.

Chemcote’s Solution

Set up scaffolding inside tank and utilised efficient surface preparation techniques to minimise mobilisation of blasting costs whilst still achieving an optimal surface to produce long term coating adhesion

Chemical Storage Tank
Site Set Up

Chemical Storage Tank
Condition upon inspection

Chemical Storage Tank
After Blasting

Chemical Storage Tank
Coating Complete

Scope

Mobilise to site and set up extraction
Abrasive blast to AS 1627.4 2005 Class 2.5, 60μm profile
Application of 1 coat of Epo-Chem RS 500P to a nominal thickness of 100μm
Application of 1 coat of Epo-Chem RA 500M to a nominal DFT of 350μm
Sand flanges and finish off internals
Carry out internal QA, DFT check

Results

By coating with the Epo-Chem™ system Chemcote restored the chemical storage tank back to service, with long term peace of mind offered to the customer

Refurbishment of J Strainer using Vinyl Ester – RB 300

Industry:

Power Generation

Date:

July 2019

Substrate:

Austenitic iron body

Products:

Chem-tect™ RB 364 Series – Glass Flake filled vinyl ester resin
Epo-chem™ RL 500PF to externals

Environment:

Sea Water

Challenge:

Strainer has been in service for 30 + years. Inspection of the strainer body, back wash covers & critical dimensions found the substrate to be severely corroded, illustrated by the extent of graphitised iron, holes through the casting and diminishing wall thickness

Chemcote’s Solution:

Composite materials were chosen to rebuild the metal loss. We then applied RB 364 series , a glass flake filled vinyl ester consolidated with composite reinforcing to return the casing to its original strength

Vinyl Ester
On Arrival
Vinyl Ester
Surface Preparation on Arrival
Vinyl Ester
Surface Preparation on Arrival
Vinyl Ester
Surface Preparation
Vinyl Ester
Surface Preparation
Vinyl Ester
First coat applied after abrasive blasting
Vinyl Ester
Pitfilling to ensure coating continuity
Vinyl Ester
Application of second coat of RB 364
J Strainer
Vinyl EsterQA testing being completed
Vinyl Ester
Application of Anti-Foul
Vinyl Ester
Vinyl EsterApplication of Anti-Foul
Vinyl Ester
Application of Anti-Foul
Vinyl Ester
Vinyl EsterFirst Coat of Anti-Foul
Vinyl Ester
Externals Completed
Vinyl Ester
Machining of Shaft Landing
Vinyl Ester
Top half complete and ready for re-assembly on site
Vinyl Ester
Top half complete
Vinyl Ester
Ready for reassembly on site
Vinyl Ester
Reassembly on site
Vinyl Ester
Completed on site

Scope:

Protect threaded holes using backing rod

Abrasive blast and treat to reduce metallic salts by hot washing and re-abrasive blast.

Apply Chem-tect™ RB 364 in two coats where required to obtain minimum thickness of 1,000μm

Pitfill to reduce the sharp edges and pit depth allowing a smooth uniform coating to be applied.

QA included spark testing and DFT to confirm coating integrity

Apply coat of RL 500 PF to externals

Results:

After 15 years of Chemcote Coatings providing long term protection on other strainers and their backwash covers within the power station, Chemcote was enlisted for repairs to the 2 large Strainers to one of the main condenser units

Sulphuric Acid Plant Concrete Slab Repairs

Industry                     

Petrochemical

Date

May 2006

Substrate

Concrete

Products

Chem-tect RB 300P Vinyl Ester Primer  Chem-tect RB 332 Vinyl Ester Resin

Environment

Sulphuric Acid has caused deterioration of the existing fiberglass matting. The failure of the previous fiberglass lining had enabled permeation, allowing serious corrosion of the concrete slab

 

Challenge

A core drilling process and testing procedure was undertaken to analyse the extent of the Ammonia Sulphate ingress before planning a work method to avoid contamination from other work happening on site

Chemcote’s Solution

Chem-tect™ Vinyl Ester system is filled with screened glassflake technology for long lasting protection from aggressive chemicals such as sulphuric acid, abrasion and high temperature environments

 

 

 

Deteriorated concrete beneath Fibreglass lining

Jack hammer used to remove debris

The lining was cut and removed by sections to allow the plant to continue operations.
The required surface preparation was undertaken to remove laitance from the concrete surface
Where repairs to the concrete were needed, the area was broken up with a Jackhammer
Crushed rock was placed in void and compactor was used to level fill
Steel Reinforcement was placed
Treatment with Vinyl Ester Primer to seal the porous surface

Core drilling samples taken to assess
extent of concrete damage

Pour fast setting Polymer Concrete was into position with an air powered hammer chisel to stabilize the ground
Trowel off and cure
Promote second coat on site for fast reaction
Top with Garnet to provide anti slip properties

Results

Chemco International’s Chem-tect™ system has provided years of maintenance-free service and excellent chemical resistance. These materials are substantially stronger than the original slab and will protect the slab in the future against mechanical damage and further sulphuric acid ingress

Blast Furnace Dust Discharge Valve Refurbishment

Industry                     

Manufacturing

Date

June 2018

Substrate

Steel

Products

Chem-tect™ RB 364

Environment

Blast furnace gas, combined with particulate at elevated temperatures 70degC

Challenge

Rebuild the internal profiles corroded and eroded away up to 10-15mm

Chemco’s Solution

RB 364 was specified for its suitability to provide corrosion and erosion protection

On arrival suffering corrosion erosion

Condition on arrival

Refurbishment process

After Coating Internals

Scope

Abrasive blast internals and externals, taking care not to damage the insert sealing ring.

Internal application of RB 364 to a minimum of 500µm

Sand smooth and pitfill with RB 364

Cast insert where required

Application of 2nd coat of RB 364

Results

Coating was completed to client’s expectations and future scheduled inspections will ensure long term protection and an extended life expectancy of the Blast Furnace valve.

Column Pump Composite Repairs

Industry                   

Power Generation

Date

April 2018

Substrate

Cast Iron Column Pump

Products

Internals, Chem-tect™ RB 364 a glass flake filled vinyl ester. Ceram-chem™ RP 500 a ceramic filled epoxy.

Externals, Epo-chem™ RS 500P a surface and moisture tolerant primer. Epo-chem™ RA 500M a glass flake filled epoxy.

Environment

Ambient Salt Water

Challenge

Chemcote were brought in to carry out pump refurbishment after catastrophic failure of bearing causing the impeller to wear through the casing of the column pump

Chemco’s Solution 

Refurbish pump lining to extend service life using glass flake filled coatings, then top coated using RP 500 to improve fluid flow efficiency.

Condition in situ

Before Blasting

After First Coat

Detailing flange faces of impeller casing

Intermediate Column Externals

Scope

Abrasive blast to AS.1627.4 to class 2.5

Masking and protection of critical tolerances and bush area on flange.

Pit filled to allow smooth transition and prevent coating defects

Sand smooth where necessary & application of RB364 to 1,000µm

Internal & external holiday testing to ensure coating continuity using the required voltage to suit the dry film thickness.

Application of the top coat Ceram-chem RP 500

Results

Improved corrosion resistance and fluid flow efficiency through the quality assurance process employed by Chemco.

Extension Leveller Cassette Corrosion Prevention

Industry                   

Manufacturing

Date

January 2018

Substrate

Steel

Products

Epo-Chem™ RL 500PF and RC 500GTC

Environment

Recycled cooling water

Challenge

Asset owners of the Extension Leveller Cassette engaged us to inspect and
nominate a complete coating solution
where standard paint systems failed to
prevent surface deterioration resulting in
large refurbishment costs

Chemco’s Solution 

RL 500PF is a surface / wet tolerant zinc rich
epoxy, required to a uniform thickness for
smooth functioning

Condition in Situ

After Blasting

Inspection in Workshop

Coating Application on Site

Scope

Grind sharp edges and weld porosity.

Abrasive blast to AS 1627.4 Class 3, 75µm profile

Application of RL 500PF with nominate thickness 300 microns

Application of 1 coat of RC 500GTC to a final DFT of 400µm

Results

Since re-coating was carried out by Chemcote, the extension leveller has been found to be in excellent condition and maintenance costs have been dramatically reduced

Emergency Condenser Water Box Repairs

Industry                   

Power Generation

Date

January 2018

Substrate

Water Box – Steel recently coated using ceramic filled epoxy

Products

Epo-Chem™ RS500P and RA500M glass flake filled epoxy

Environment

Pressure vessel containing clean brackish water at ambient temp

Challenge

Carry out composite repair (rated to 1200psi) to hole through including ongoing repairs during short outages to failing ceramic lining.

Chemcote’s Solution 

RS 500P is a surface and wet tolerant Mio Epoxy primer designed for application on surfaces where high humidity is a concern. Due to its shorter cure time it was also used to laminate the damaged area (internally and externally) to enable rapid return of water box to service.

On Arrival

After reinforcing with composite mat

External Composite Repair

Scope

Needle gun and bristle blast internal and externals of the affected area, spot blast 100mm of coating outside of the repair area.

Carry out composite repairs to Chemcote’s specifications using RS500P.

Application of top coat Epo-Chem RA500M to a nominal WFT of 250-300µm.

Results

Continuous repairs are required after relining in 2015 using a ceramic filled epoxy was found to have localised failures within 3 months of installation. All repairs carried out by Chemcote have been found to be in excellent condition.

Long Term Corrosion Protection to Screw Agitator

Industry                           

Food and Beverage

 

Date

February 2018

 

Substrate

Carbon steel Auger with a red oxide coating, in service for 2 years

 

Products

Epo-Chem RS500P & RA500M a moisture and surface tolerant MIO primer with a glass flake filled epoxy top coat.

 

Environment

Constant salt water contact in seaweed filtering process

 

Challenge

Agitator had deteriorated over time causing rust and scale to contaminate the product

 

Chemco’s Solution

Repeat abrasive blasting and hot washing to reduce metallic salts below 25 ppm. Pit filling of deep metal loss and composite reinforcement where required.

 

On Arrival

Condition on Arrival

Finished Product

Completion

 

Scope

Abrasive blast to AS 1627.4 Class 2.5, nominal 75µm profile.

High pressure hot wash to reduce soluble salt levels below 25ppm

Repeat Abrasive Blast

Insert backing rod in shaft end to prevent blocking up with coating

1 coat of RS500P at 100µm nominal thickness

2 coats of RA500M at 600µm nominal thickness

Carry out QA, spark test at 4kV and DFT to confirm coating integrity.

 

Results

Quick turn-around allowing auger to return to service within the month.

Strict QA requirements including DFT and holiday testing to the required voltage to ensure many years of service

 

Corrosion Protection of Basket Strainer

Industry                           

Steel Manufacturing

Date

February 2018

Substrate

Basket Strainer – Steel

Products

Epo-Chem™ RS500P a wet and surface tolerant epoxy primer containing 100% solids and RA500M a wet tolerant, glass flake filled epoxy containing 100% solids. Both products are capable of being applied in high humidity including under water.

Environment

Salt water strainer

Challenge

Repeat abrasive blasting and hot washing to reduce metallic salts below 25 ppm. Pit filling of deep metal loss and composite reinforcement where required.

Chemcote’s Solution

Repeat abrasive blasting and hot washing of basket strainer to reduce metallic salts below 25 ppm. Pit filling of deep metal loss and composite reinforcement where required.

On Arrival

After 3rd Blast

After 2nd blast and 2 hot washes

Scope

High pressure hot wash and repeat abrasive blast to reduce soluble salt levels below 25ppm

Abrasive blast to AS 1627.4 Class 2.5, nominal 75µm profile.

Application of RS500P, then two coats of RA500M Series to obtain minimum thickness of 500µm

Cast sealing ring for O ring groove rebuilding the original surface profile using RA500M

Carry out QA, spark test at 4kV and DFT to confirm coating integrity.

Quick turn-around allowing minimal disruption to meet project milestone targets.

Strict QA requirements including DFT and holiday testing to the required voltage to ensure many years of high performance

FDA Approved Coating of Bread Mixer

Industry                           

Food and Beverage

 

Date

June 2017

 

Substrate

Commercial Steel Bread Mixer and Bowl

 

Products

Epo-Chem RS 500P and Epo-Chem RA 500M

 

Environment

2 tonne bread mixer and bowl requiring Food Safety Certification

 

Challenge

 

Difficult clean due to heavy grease and yeast build up, whilst ensuring critical equipment is protected.

 

Chemco’s Solution

Mask all critical equipment for surface preparation

 

In factory, prior to works

Mixer on arrival

Preparation of surface

Coated and Installed

 

Scope

Hot wash on arrival

Remove remaining grease and yeast contamination using a solvent wash

Abrasive blast to AS 1627.4, class SA 2.5 with a 50µm profile.

Application of 1 coat of Epo-Chem RS500P @ 100µm DFT to all bare metal areas

Application of 1 coat of Epo-Chem RA 500M with a final nominal thickness of 400µm

Results

Refurbishment carried out in a shorter time frame than required, for prompt return to service.

Protection of Agitator Shaft in Chemical Plant

Industry                       

Petrochemical

 

Date

July 2017

 

Substrate                      

Duplex Stainless Steel

 

Products                       

Chem-tect™ RB 300 Series – Vinyl ester Glassflake coating – providing excellent resistance against corrosion and abrasion, high temperatures and severe chemical environments.

 

Environment               

Installation of new mixing tank containing high pH contents at 60°C, with 50% solid contents and 50% iron hydroxide.

 

Challenge                     

Abrasion protection on leading edges using composites and insitu touch up after re-assembly.

 

Chemco’s Solution    

Specification and application of RB 300, a high temperature and chemically resistant coating system to get the longest life out of the new plant

 

Duplex Shafts Blasted with First Coat Applied

Application of Final Coating

Coated and installed

Waste Processing Plant

 

Scope                             

Abrasive blast to AS 1627.4, class SA 2.5 with a nominal 60µm profile.

application of RB 300 in 2 coats with a nominal thickness of 1,000µm.

Application of 1 layers of 250g/m² multi directional mat CSM

Post cure to 60°C for 4 hours as required to manufacturers specifications

 

Results                         

Quick turn-around allowing minimal disruption to meet project milestone targets.

Strict QA requirements including DFT and holiday testing to the required voltage to ensure many years of high performance

This application will provide at least 10 years of corrosion free service with minimal maintenance

Cavitation Protection on Valve Paddle

Industry                           

Power Generation

 

Date

2017

 

Substrate

Rubber Lined Mild Steel

 

Products

Epo-Chem™ RS 500P a wet and surface tolerant mio epoxy primer

Epo-Chem™ RP 500 series, a moisture tolerant ceramic filled epoxy top coat, providing excellent long term cavitation resistance.

InD-cote™

 

Environment

15°C – 30°C sea water

 

Challenge

The 10-year-old valve experiencing cavitation damage with replacement unavailable within a reasonable time frame. Quick turnaround for return to service required.

 

Chemco’s Solution

Protect critical surfaces by masking and abrasive blast areas to be repaired.

Weld new gussets to provide mechanical strength where lost.

Application of Epo-Chem™ RS 500P to a nominal thickness of 100µm, rebuild original profile height using InD-cote™ and top coat using Epo- Chem™ RP 500 with a nominal DFT of 350µm

 

Typical extent of cavitation found
Typical extent of cavitation found

After abrasive blasting to expose extent of the damage
After abrasive blasting to expose extent of the damage

Kevlar is used to provide cavitation resistance
Kevlar is used to provide cavitation resistance

Paddle refurbishment complete
Paddle refurbishment complete

 

Results

Valve parts are not available from the OEM and a replacement was going to cost an estimated $120K. The repairs have effectively saved the asset owner considerable time and money in full valve replacement. The refurbished paddle is now reinforced using Kevlar and expected to provide more than 10 years of additional service life. For more information please feel free to contact Chemco on 1300 CHEMCO (243 626).

 

Speak To A Specialist Now!

 

Corrosion Protection for Condenser Tube Sheet

Industry                           

Power Generation

 

 Date

2016

 

 Substrate

20 Year Old – Bronze tube sheet

 

 Products

Chem-tect™ RB 300 series, a glass flake filled vinyl ester, provides excellent permeation resistance and high dielectric strength.

 

 Environment

40-60°C, sea water

 

Challenge

To provide a long term solution for the corroded tube ports and tube sheet.

 

Chemco’s Solution

Tube internals were protected by inserting specially ordered silicon plugs to prevent abrasive blasting from damaging wall thickness. Abrasive blast as per required standard and remove silicon plugs and glue nylon tube inserts into position and then pitfill all deep cavities using RB 300 Series. We used the proprietary method to obtain a flat surface using RB 300 Series.

 

Tube bundle protection ready for abrasive blasting
Tube bundle protection ready for abrasive blasting

Close up of some of the damage on tube sheet
Close up of some of the damage on tube sheet

Installation of nylon ferrules and pit filling
Installation of nylon ferrules and pit filling

Tube sheet refurbishment complete
Tube sheet refurbishment complete

 

Results

An estimated replacement cost was in the range of $500K and this refurbishment is expected to extend the life for another 20 years. Chemco is available for all corrosion related issues with nearby ancillary equipment. For more information please feel free to contact Chemco on 1300 CHEMCO (243 626).

 

Speak To A Specialist Now!

 

Life Extension of 40 year old Structural Steel

Industry                           

Power Generation

 

Date

2016

 

Substrate

Critical overhead pipe support structure outside turbine hall

 

Products

Epo-Chem RS 500P a wet and surface tolerant mio epoxy primer and Epo-Chem RA 500 series, a moisture tolerant glass flake filled epoxy top coat, providing excellent long term corrosion resistance.

 

Environment

15°C – 60°C sea water

 

Challenge

The original environment was considered atmospheric, due to regular leaking valves and flanges the coating specification was necessary to be reclassified to immersed after the original paint system failed.

Access difficulties and age were all a consideration as part of the assessment process. Abrasive blasting was not possible as the containment and clean up costs we’re prohibitive.

Chemco’s Solution

Mobilise to site

Ultra high pressure water blast up to 20,000 psi using our small foot print machine after  a quick mechanical clean in the difficult to reach areas. Carry out soluble salts test to ensure the levels are within the coatings parameters.

Application of Epo-Chem RS 500P to a nominal thickness of 100µm and top coat using Epo-Chem RA 500 with a nominal DFT of 350µm

Typical extent of corrosion found
Typical extent of corrosion found

Ultra high pressure water blasting
Ultra high pressure water blasting

Gaps between pipe saddles and pipe are sealed to prevent moisture and air

Critical support structure now protected

 

 

Results

Saved hundreds of thousands of dollars in replacement costs and the asset owner is rest-assured that Chemco will provide long term corrosion protection, evident through the years of applications around the power station.

 

 

Corrosion Protection of Super Duplex against Sulphuric Acid

Industry                     

Mining and Mineral Processing

 

Date

July 2017

 

Substrate

Super Duplex Steel

 

Products

Chem-tect™ RB 364CS vinyl-ester glassflake

Chem-tect™ RB 300TC vinyl-ester topcoat

Chem-tect RC 364

 

Environment             

Nickel Laterite mine operating at 100°C. Vessel is required to contain and hold Sulphuric Acid Slurry as part of the leaching process.

 

Challenge

Internals had previously been coated with a widely accepted epoxy which failed within months causing the substrate to corrode. Pitting was experienced and protection against long term exposure to acid was required.

Externals needed protection from acid rain and atmospheric corrosion, also needing a durable hard-wearing finish.

 

Chemco’s Solution

Achieving adequate adhesion to Super Duplex is a challenge for every coating, RC364 was selected for its adhesion to exotic materials.

RB 300 provides excellent corrosion resistance, creating an impermeable barrier between the process environment and substrate.

 

Scope                        

Abrasive blast with Aluminium Oxide to class SA 2.5 90μm surface profile.

Apply RC364 to a DFT of 400μm on internals and externals

Apply RB364CS to a total DFT of 1mm on internals

Apply RB300TC to the total DFT of 400μm externally

 

Dome condition before blasting and coating
Condition before blasting and                                   coating

Dome after blasting and coating
Vessel after blasting and coating

External after blasting and coating
External after blasting and coating

Results

After a year the tank is still in excellent condition, the client has requested the same treatment on other vessels within the site.

Coating selection, approvals and application was performed by CCS – Distributor Agent of Chemco International in Western Australia.

 

Speak To A Specialist Now!

 

Preventing Stress Corrosion Pitting

Industry                     

Mineral Processing

Date

2007

Substrate

304 Stainless Steel – Ammonia absorber and circulation tank.

Products

Chem-tect™ RF364 – vinyl ester / acrylic co-polymer enhanced with flaked glass; very suitable for immersed environments where superior resistance to chemical attack is required.

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

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.

Chemcote’s 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 Chemco Standards.

Application of a Chem-tect™ RF 300 in 3 coats including strip coat all difficult to reach areas.

De-mobilise from site.

Site Layout before equipment setup
Site Layout before equipment setup

Previously applied coatings delaminated
Previously applied coatings delaminated

Ammonia Absorber
Ammonia Absorber

Circulation Tank
Circulation Tank

Results

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.

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Improve Pump Efficiency with Chemco

Industry                     

Water Utilities

 

Date

April 2017

 

Substrate

Cast iron body

 

Products

Chem-tect™ RB 364

Epo-chem™ RP 500

 

Environment

River Water

 

Challenge

The pump had dropped off in efficiency due to the combination of corrosion erosion and mechanical fatigue. This was due to a poorly specified and applied coating which was delaminating allowing corrosion to exist.

 

Chemco’s Solution

After 8 years in service the substrate was corroded and heavily contaminated with metallic salts. Treatment using a combination of methods including abrasive blasting, hot washing and acid washing to reduce salts below 25ppm.  We then recommended the application of 2 coats of Chem-tect™ RB 364; a glass flake filled vinyl ester providing an excellent corrosion barrier and long term protection. We then applied 2 coats of Epo-chem™ RP 500 to enhance fluid efficiency in turn reducing power consumption.

 

On arrival ready for chamfer grinding
On arrival ready for chamfer grinding

Chamfer on split face and removal of salts
Chamfer on split face and removal of salts

Pitt-filling and intermediate coat applied
Pitt-filling and intermediate coat applied

Completion of internal lining
Completion of internal lining

 

Scope

Strip and assess

Manufacture template to ensure mating faces match

Grind chamfer on all flanged faces, allowing the coating to be applied on the flange face preventing future crevice corrosion.

Protect critical dimensions

Abrasive blast and treat to reduce metallic salts by hot washing and re-abrasive blast.

Apply corrosion barrier Chem-tect™ RB 364

QA included spark testing and DFT

Apply topcoat of Epo-chem™ RP 500

 

Results

By coating with Chem-tect™ RB 300 & Epo-chem™ RP 500, future corrosion erosion is prevented with a reduced amount of friction through composite technology. The pump now functions more efficiently when in use consuming less power, which led to carbon credits and a reduction of greenhouse gas emissions. The payback period of the entire refurbishment worked out to be only 14 months.

 

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Apply Coating on Wet Surfaces using RL 500PF

Industry                     

Petrochemical

 

Date

July 2016

 

Substrate

Steel Substrate

 

Product

Epo-chem™ RL 500PF

 

Environment

Wet and Cold Column Externals

 

Challenge

The lagging was removed to extend the life of the shell externals. While the vessel was in service, surface preparation and corrosion application were undertaken. Surface temperatures were ranging between -5°C to around +25°C. This causes the substrate to sweat heavily during coating application.

 

Chemco’s Solution

Wet & Rust Tolerant Epo-chem™ RL 500PF was recommended for this application to prevent CUI (corrosion under insulation). This system requires minimum surface preparation (i.e. no need for dry grit blasting). Rain, water, condensation or high humidity have no effect on freshly painted surfaces.

In this case, abrasive blasting was possible and coating was applied to an average DFT of 300µm total, achieved in two coats.

 

Column prior to start & partially lagged.
Column prior to start & partially lagged.

Unlagged cold zone
Unlagged cold zone

Unlagged corroded zone near top
Unlagged corroded zone near top

Maintenance painting completed whilst in service
Maintenance painting completed whilst in service

 

Results

This is a prime example of innovative technology being used to save the Clients existing plant from the possibility of failure. The protective coating was able to provide a vast improvement in plant safety and also exceeded the engineer’s expectations, to the point that Chemco’s Epo-chem™ RL 500PF is now specified on all similar applications within this site.

Epo-chem™ RL 500PF is designed to provide corrosion protection for applications of up to 150°C and also is designed for application on new and aged galvanised steel, making it ideal for electricity pylons, exhaust stacks and CUI applications.

 

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Chem-tect™ RA 300 for Stainless Steel Agitator shaft

Industry

Chemical

Date 

November 2012

Substrate 

Stainless Steel Agitator shaft

Products 

Chem-tect™ RA 300

This is a glass-flake vinyl ester coating providing excellent resistance. Ideally suitable for Caustic alkalis, hypochlorite bleaches & organic solvents’. Res. Max.80°C.

Environment 

Ambient temperature high range pH mixing tank.

Challenge 

The project had to finished in a very fast turnaround of 2 days.

On arrival Stainless Steel Agitator
On arrival Stainless Steel Agitator

Close up illustrating chemical resistant cloth application
Close up illustrating chemical resistant cloth application

Final coat applied ready for post cure and packaging for return transport
Final coat applied ready for post cure and packaging for return transport

Chemcote’s Solution 

Application of a high temperature and chemically resistant coating system (Chem-tect™ RA 300) which can provide a quick turnaround.

Scope

Abrasive blast to AS 1627.4 with a profile of 75µm minimum.

Application of RA 332 in 2 coats with a nominal thickness of 1,000µm.

Application of 400gm/m² CSM on all edges of paddles in strips between 1st and second coat. Followed by applications of RA 300 series in three coats as per Chemco specification.

Post cure as required to manufacturers specifications

Results

Quick turn around and back in service allowing minimal disruption to production requirements.

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Wine Tank Refurbishment

Industry                     

Food & Beverage

 

Date                           

January 2017

 

Substrate                  

Aged Concrete Tank

 

Products                   

Damp-crete™ RH 800 (Concrete Primer)

Chem-concrete™ RI 800 (Flexible filler)

Epo-chem™ RB 500 (Wine & Beer Approved)

 

Environment             

Wine

 

Challenge                  

System applied within the past 18 months was not FDA approved and tainted 1,000’s of litres of wine. Removal of existing delaminating coating system and to provide a sound coating solution system to prevent future leaks and tainting of final product.

 

Chemco’s Solution  

We recommended priming with RH 800, a moisture tolerant damp concrete primer, followed by RI 800 for the deep pitted areas and any joins that require filling. Top coated using RB 500 and chopped strand mat to prevent coating from cracking when the precast pieces of concrete move. This system has an extremely fast turnaround and cure time.

The benefits include no odour during application and is approved for wine and beer tank applications.

 

Wine leaking from concrete tank
Wine leaking from concrete tank

Pit filling and lamination of all construction joins
Pit filling and lamination of all construction joins

Application in confined space in comfort
Application in confined space in comfort

Completed internal lining
Completed internal lining

 

Scope                        

Remove existing lining of the wine tank by destructive methods and abrasive blasting to provide a surface profile. Application of coatings as above, allow to cure for 3 days prior to return to service.

 

Results                      

A long term leak free internal composite surface designed for beer and wine applications approved by the FDA.

 

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Chem-tect™ 300 Series for Concrete Bund

Industry                           

Chemical

 

Date

December 2016

 

Substrate

Concrete Bund in a chemical plant.

 

Products

Chem-tect™ RA 364

 

Environment                   

Highly corrosive range of chemicals including Sodium Hydroxide and Hydrochloric Acid.

 

Challenge

Upon inspection, the concrete bund was identified to be in a poor condition. This is due to the existing surface deteriorating after years of exposure. There are many locations on the bund that show a degree of damage and there is also evidence of chemical pooling. This seems to indicate that the fall is not functioning properly and, therefore, needs to be addressed and reinstated.

 

Chemco’s Solution

To ensure that the maximum life of the coating is achieved for our client, we reviewed the environment conditions, and we are specifying the Chemco International Glass Flake Filled Chem-tect™ 300 series coatings. These coatings have been chosen as they offer excellent chemical and corrosion protection.

 

Results

This coating project was completed on time, to budget and an inspection after 2 years has been recommended. Our Client was pleased with the result and the service.

 

Tanks leaking and pooling chemicals
Concrete Bund – Tanks leaking and pooling chemicals

Removal of 10 year old lining on concrete bund.
Removal of 10 year old lining on concrete bund.

Priming and filling complete on concrete bund
Priming and filling complete

Completed work, ready for new tank installation
Completed work, ready for new tank installation

 

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RE 500P & RW 500 Applied on Hot Car Structure

Industry                   

Steel Manufacturing

 

Date

September 2016

 

Substrate

Mild steel substrate

 

Products

Epo-chem™ RE 500P & RW 500

 

Environment

1,000°C Coking Coal transport wagon where 80°C recirculated water is used to quench the load.

 

Challenge

After successful spot repairs on existing hot car structures insitu, we were asked to provide the same solution on a brand new fabrication. The project consisted of a long wall approximately 20 mt long and 2 side walls approximately 4 metres long each. This was an excellent opportunity for Chemco to provide ultimate surface preparation and application. The challenge was the length and weight of the items and the attention to detail required around all the crevices and welds.

 

Chemco’s Solution     

We recommended Epo-chem™ RE 500P a high temperature resistant surface tolerant, Novolac Epoxy primer. Top coated with Epo-chem™ RW500, glassflake filled, high temperature resistant Novolac Epoxy. The coating system provides excellent corrosion/erosion resistance against this environment.

 

Scope                         

Abrasive blasting to AS 1627.4 Class 3, 60µm profile.

Application of RE 500P in one coat at 100µm nominal and application of RW 500 at 350µm Dry Film Thickness (DFT)

 

Results

Most linings were breaking down and failing within a short period of time, between 2 & 8 weeks of service. An inspection of our spot repairs after 12 months have indicated that our glass flake coating system can withstand these harsh environments. We expect the freshly coated components to provide the most superior coating system used on this structure to date. This saves the client a lot of money and reduces a lot of equipment down time.

Hot car structure during fabrication
Hot car structure during fabrication

RE 500P applied at 100um
RE 500P applied at 100um nominal

RW 500 applied at 350um to 20mt long frame
RW 500 applied at 350m to 20mt long frame

 

Carefully loading the finished item
Carefully loading the finished frame

 

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RL 500PF for Castor Segments

Industry                      

Steel Manufacturing

 

Date

September 2012 – 2016

 

Substrate

Aged Carbon Steel

 

Product 

Epo-chem™ RL 500PF – a surface/moisture tolerant zinc rich epoxy coating resistant to 150°C which can also be applied on hot surfaces.

 

Environment 

Quenching station – Steam with radiating heat at 130°C

 

Challenge

These segments are subjected to extreme conditions as part of the steel casting process. Upon inspection, we found severe paint breakdown and asset deterioration. This was due to previously applied coatings incapable of resisting the high temperatures. Premature corrosion was also found during inspection.

 

Chemco’s Solution     

We recommended 2 coats of Epo-chem™ RL 500PF. This coating system is known to provide excellent long term corrosion resistance for this type of environment.

 

Scope                         

Abrasive blasting to AS 1627.4

Application of 2 coats of RL 500PF @ 300µm

 

Results 

The client welcomed a trial in an effort to reduce long term maintenance costs. He found this was possible using the Chemco anti corrosion coating system. After equivalent time in service our zinc rich high temperature resistant epoxy coating system was showing no signs of failure whatsoever. A long term corrosion protection was achieved. All segments are now specified with this Chemco system

 

After pre abrasive blasting
After abrasive blasting

RL 500PF during application
RL 500PF during application

RL 500PF application completed
RL 500PF application completed



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Epo-chem™ RL 500PF on Galvanised Steel

Industry                           

Marine

 

Date

October 2016

 

Substrate

Galvanised Structural Steel

 

Products

Epo-chem™ RL 500PF

 

Environment                   

Aggressive marine conditions

 

Challenge

This project presented two challenges to our team. The first challenge was coming up with a coating system that would adhere well to galvanised steel. The second challenge was making sure that this system would also be suitable for the very aggressive coastal environment.

 

Chemco’s Solution

Epo-chem™ RL 500PF is a surface and moisture tolerant epoxy that is well suited to this environment as it has superior adhesion to new or aged galvanised surfaces. Firstly, we prepared the surface ready for the application of the primer. Our team then applied 2 coats of Epo-chem™ RL 500PF. To ensure no moisture could form in the crevices we sealed all cracks and crevices using a polyurethane sealant. The fascia was finished off with a polyurethane finish coat in black.

 

Results

After extensive surface preparation and surface rectification we were able to apply the best protective coating solution for this environment.

 

Galvanised steel ready for protective coating
Galvanised steel ready for protective coating

Every Crevice and crack had to be filled to ensure no moisture could build up
Every crevice and crack is filled to prevent moisture and salts from penetrating and causing premature corrosion

Coating application by innovative methods
Coating application by innovative methods

Final coat of Protective coating applied
Final coat of Protective coating applied

 

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Corrosion Protection For Hot Salt Water

Industry:

Power Generation

Date:

2016

Substrate:

New fabrication using mild steel

Products:

Chem-tect™ RB 300 series

Epo-chem™ RL 500PF

RC 500GTC finish coat

Environment:

Hot salt water

Challenge:

The project was a series of pipe spools with diverse configurations and diameters. These items required long term corrosion protection against high temperature salt water. This would be classified as an extremely corrosive environment. For this reason they demanded a superior coating system. The complex schematics and pipe diameters made it challenging to coat internally. Field fitting of flanges was required to ensure the completed spools lined up.

Pipe spools with challenging configurations
Pipe spools with challenging configurations

Applying RB 300 to the internals of a pipe the only way possible
Applying RB 300 to the internals of a pipe the only way possible

Chemcote’s Solution:

Chemcote’s solution was to apply Chem-tect™ RB 300 series to the internals of the pipework. This coating is a glassflake filled vinyl ester. Glassflake filled coatings have proven to be the most suitable where good corrosion resistance and excellent mechanical properties are required.

Scope:

Internal Corrosion Protection

We started by grinding welds and sharp edges prior to abrasive blasting.

We then abrasive blasted to class AS 1627.4 – Class SA 3.0.

Followed by an application of Chem-tect™ RB 300 series in 2 coats to acheive a total DFT of 1000um.

DFT tests were then carried out to confirm coating the thickness.

Finally we carried out high voltage test at 8,000 volts to identify and rectify defects.

Holiday testing RB 300 internal coating
Holiday testing RB 300 internal coating

External Corrosion Protection

The primer applied was 2 coats of Epo-chem™ RL 500PF.

The finish coat applied 2 coats of Chemco RC 500GTC.

Results:

The majority of work was conducted in our purpose built workshop. The finishing touches were carried out onsite once the field fitted flanges were complete. The asset owner was extremely pleased with the quality, turnaround time and communication throughout this project. The coating will exceed the life requirements of 25 years and reduce maintenance costs in the future.

Finished elbow showing face prepared to prevent crevice corrosion
A finished elbow showing the face prepared to prevent crevice corrosion

Condenser Tube Sheet

Industry:                            

Power Generation – Sugar Mill

 

Date:

2015

 

Substrate:

8 Year Old – Mild Steel water boxes & Stainless Steel tube sheets

 

Products:

Chem-tect™ RB 300 series, a glass flake filled vinyl ester, provides excellent permeation resistance and high dielectric strength.

 

Environment:

40-60°C, brackish / sea water

 

Challenge:

New tubes were installed in the condenser tube sheet made from an exotic Stainless Steel compared to the low grade tube sheet. We were asked to provide a solution with a coating with a high dielectric strength to prevent the galvanic reaction between dissimilar materials.

 

Return Side plug removal nearly complete
Return Side plug removal nearly complete

8 year old Steam Condenser Unit
8 year old Steam Condenser Unit

Installation of plastic caps to protect the internals from abrasive and coating
Installation of plastic caps to protect the internals from abrasive and coating

Pit filling on baffle walls between coats
Pit filling on baffle walls between coats on the condenser tube sheet

 

Chemco’s Solution:

Tube internals were protected by inserting specially designed plastic caps on Inlet/Outlet and Return side of Water Box. This protected the condenser tube sheet.

The entire face was hot washed to remove any lubricants and other potential contaminants before abrasive blasted to ensure surface is clean and the correct surface profile is obtained. RB 300 was applied to tube-sheet face, followed by some other areas considered critical, such as the baffle plates where the existing coating has failed due to under specification. Carry out high voltage spark test beyond Australian Standards to ensure coating integrity.

 

Results:

The extended life of the coating is expected to exceed 20 years in service, the plant owner is requesting Chemco to assist further with other corrosion related issues with nearby ancillary equipment.

 

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