UHP Waterjetting Operation Presented by Rick Dupuy UHP Projects Inc Learning Outcomes Describe the purpose of surface preparation and what it includes Using SSPC VIS 4NACE VIS 7 determine the initial condition of a surface and assess the level of cleanliness ID: 533975
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Slide1
Steps to a More Effective UHP Waterjetting Operation
Presented by:
Rick Dupuy
UHP Projects, IncSlide2
Learning Outcomes
Describe the purpose of surface preparation and what it includes
Using SSPC VIS 4/NACE VIS 7, determine the initial condition of a surface and assess the level of cleanliness
Using SSPC SP-WJ/NACE WJ standards to demonstrate ability to achieve the level of waterjet cleanliness required for a given job
Identify the components of the waterjetting systemSlide3
3 Viewpoints required for successful coatings applicationOwner / Inspector
Contractor
Coatings Manufacturer
3 Performance Criteria needed for successful coatings
Visual – SSPC standards
Profile – based on coatings manufacturer requirements for the coatings specified
Non-visible contaminantsSlide4
UHP Waterjetting Surface Preparation Processes
Pre-Cleaning
Cleaning
Post-Cleaning – before coating applicationSlide5
Pre-Cleaning
Pre-cleaning may involve:
Removal of grease/oil, gross contaminants
May require the use of degreasers or other solvents and low pressure water cleaning
Repair of defects in steelSlide6
Pre-cleaning - SSPC SP 1 Solvent Cleaning
Always performed first
if necessary
, regardless of which surface preparation method is selected
Requires removal of all visible oil, grease, drawing compounds, and other contaminants from steel prior to surface preparationSlide7
Surface Imperfections May
N
eed
to be
C
orrected Prior
to
Surface Preparation
Sharp edges
Weld spatter
Burrs
Pits
CrevicesLaminationsPorositySlide8
SSPC PA Guide 11
This guide discusses the technique called “stripe coating” or “striping” as a way of providing extra corrosion protection measures on edges, outside corners, crevices, bolt heads, welds, and other irregular steel surfaces, including optional surface preparation techniques for sharp edges to improve coating performanceSlide9
Surface Preparation
Actual surface preparation involves:
Preparing the surface to accept the coatings specified
Ensure that the surface is cleaned to the standard specified and for the coatings specified
Removing existing coatings, rust and other unwanted materials from the surface
Waterjetting surface to a stated visual cleanliness levelSlide10
Common Surface Preparation Methods and SSPC Standards
Degreasing (SP 1)
SP WJ-1 Clean to Bare Substrate
SP WJ-2 Very Thorough Cleaning
SP WJ-3 Thorough Cleaning
SP WJ-4 Light CleaningSlide11
Visual Guides for Cleaned Steel
SSPC VIS 1 (Dry Abrasive Blast Cleaning)
SSPC VIS 3 (Hand and Power Tool Cleaning)
SSPC VIS 4 (Waterjetting)
SSPC VIS 5 (Wet Abrasive Blast Cleaning)
NSRP Flash Rust GuideSlide12
Post-Cleaning
Post-cleaning prior to coating application involves verifying that the surface is:
Dry
Still free of contaminants, including dust and dirt that could have accumulated since surface preparation
Still at the required cleanliness level
Ensure that the surface is an acceptable level of flashrust for the coatings specifiedSlide13
Advantages of UHP Waterjetting
Used
where profile is already established
Does a good job of reducing/eliminating surface contaminants
Used where solid particles will cause harm - controls unwanted emissions
Can reduce disposal costs particularly on hazardous coatings
Can minimize containment requirements
Can be used to remove coatings layer by layer
Less interference with other trades and activities
Removes elastomeric coatings effectivelySlide14
Pressures for Cleaning
with Water
Low-pressure water cleaning (LP WC): less than 5,000 psi (34 MPa)
High-pressure water cleaning (HP WC): 5,000 to 10,000 psi (34 to 70 MPa)
High-pressure waterjetting (HP WJ): 10,000 to 30,000 psi (70 to 210 MPa)
Ultra High Pressure waterjetting (UHP WJ): above 30,000 psi (210 MPa)Slide15
Top Coats
Primer
SubstrateSlide16
Types of UHP Tools
Manual Guns
Manually operated vacuum attached
Floor, Deck, Wall (
“
Lawnmower
”
)
Automated /
RoboticSlide17
How do You D
ecide
W
hich
E
quipment
to
Use
?
Size of project and project requirements
Project time constraints or productivity requirements
Knowledge level of personnel doing the work
Jobsite requirement for water collection
Full removal or partial removal of coatingsHazardous coating removal and personnel/environmental protectionSlide18
Typical Equipment Setup for
Manual
G
un
O
perationSlide19
Remote shutoff
rotating nozzle
Hand activated on/off – double trigger
Correct Stance and Hose PlacementSlide20
Recommended PPE
Standard PPE – Safety glasses, hard hats, Hearing protection, FRC
Cut resistant gloves
Metatarsal Boots
Full Face Shields
Heavy rain suits
Task specific PPE – Safety harnesses, respirators, H2S monitors, etc.Slide21
Cut Resistant Clothing is
Becoming
M
ore
O
perator FriendlySlide22
Automated / Robotic Equipment
Vacuum Recovery removes both coatings and effluent water from the nozzle (Keeps water from pooling on the surface)
Closed Loop (Water filtered and recirculated)
Open Loop (Water used once)Slide23
Automated UHP Equipment
Vacuum SystemSlide24
Remote-Control SystemSlide25
Horizontal Large Surface RobotSlide26
Manually Operated V
acuum
A
ttached EquipmentSlide27
Primary Components of the Waterjetting System
Pump – Positive Displacement or Intensifier
Pressure and volume are considerations
Type of power source
Gun – Dry shut off or Dump
Rotating or non-rotating
Hose
Vacuum system if required
Nozzle
AccessoriesSlide28
Skid-Mounted UHP PumpSlide29
Skid mounted UHP PumpSlide30
Typical Single User PumpSlide31
Pump with Vacuum RecoverySlide32
Vacuum Systems
Sized to the flow and the application.
Venturi nozzle to drum
Skid mounted vacuum systems
Large vacuum truck
How is the effluent from the vacuum going to be handled
Multiple tools from same system
NEVER
put your hand in front of the vacuum hose.Slide33
Vacuum System
Vacuum equipment is often integrated into a skid package. This unit can be mounted on the back of a pickup truck with a 220 gallon tankSlide34
40-55,000 psi HoseSlide35
Hoses and Connections
Burst rating should be a minimum of 2.5 times working pressure of the hose
Test high-pressure hoses at 1.5 times working pressure
Fittings should be rated for the working pressure
Inspect hoses for shroud abrasion, leaks, and flow restrictions (such as squashed fittings) before each use Slide36
Hose Accessories: Bend Restrictors, Containment Grips (Whip Check)Slide37
Proper UHP Hose Care
Never run hoses over sharp edges – use softeners and suspend hoses
On long vertical runs don’t let the hose connectors bear the full weight of the hoses
Don’t let vehicle traffic run over hoses
Store hoses in a protected location with ends connected
Always clean and lubricate ends before connectingSlide38
Handheld UHP tools
Attached to the UHP pump by hose
Incorporates a control valve, guard, lance (barrel), usually a rotation device and nozzle
Comes in various lengths, normally with dual triggers. May also have a support handle and a shoulder stock
The control valve used to relieve the pressure further defines the gun typeSlide39
Handheld UHP tools
Dump gun:
Moves pressure to the atmosphere, i.e. water continues to flow but at low pressure when the valve is released
Dry shut-off gun:
Pressure is retained in the system with a shutoff control valve, i.e. you see no water at the gun, but it is re-circulated to the systemSlide40
Dump Gun
Dump gun:
Designed with a tube for depressurization (dump mode) at the nozzle
May be used alone or in a multi-gun operation with an adjustable constant pressure valve to ensure that pressure does not change abruptly
When the dump gun valve is closed, the gun is blasting with free passage of water through the nozzle
When the valve is released the water is “dumped” at the gun
The operator can modulate the pressureSlide41
Dump GunSlide42
Dry Shut-Off Gun
Designed for use with a pressure regulator (or tumble box) for single or multi-gun applications
When the internal valve is open, water flows through the nozzle. When the operator closes the valve, there is no flow through the gun
The shut-off gun is either
“
on
”
or
“
off.
”
The operator cannot modulate the pressure at the trigger. This can slightly improve productivity
Pressure is relieved away from the operator
The tumble box is designed to maintain constant pressure in the hose and gun. Slide43
Dry Shut-Off GunSlide44
Nozzles
Rotating
Non-Rotating
Self-rotating
Fan or zero-degree
Self-propelled or air-propelled
Number of orifices and size
Wear guards availableSlide45
UHP Nozzle Assemblies
Nozzles are usually multi-orifice configurations
Use sapphire or diamond orifices for UHP WJ.Slide46
UHP Waterjetting is a Proven T
echnology
with
P
roven Benefits
Write good specifications
Choose an experienced UHP contractor Use the correct equipment for the projectFollow good quality practicesSlide47
Questions?