RAISED FACE FLANGES

Super Industries
“Global Manufacturer of Heavy & Custom Engineered Fasteners for Oil & Gas, Power & EPC Contractors.”

1. Industry Context & System Relevance

Role of Raised Face Flanges in Pressure Systems

Raised Face Flanges (RF Flanges) are integral components in pressure piping systems, forming detachable, bolted joints that enable:

• Pipeline assembly and disassembly
• Equipment connection (valves, pumps, vessels)
• Maintenance accessibility
• System isolation and modification

These flanges are designed to maintain leak-tight integrity under internal pressure, thermal loads, and external mechanical forces, making them critical in safety and performance assurance of industrial piping systems.

Application Across Industrial Sectors

Raised Face Flanges are extensively deployed in:

Oil & Gas Pipelines

• Transmission and distribution of crude oil and natural gas
• High-pressure flow lines
• Compressor and pumping stations

Refineries

• Hydrocarbon processing units
• Distillation columns
• Reactor feed and product lines

Petrochemical Plants

• Polymer production systems
• Chemical reactors
• Solvent handling pipelines

Power Generation

• Boiler feedwater systems
• Steam lines (HP/HT)
• Turbine auxiliary piping

LNG Terminals

• Cryogenic service (material dependent)
• Storage tank connections
• Regasification units

Offshore Platforms

• Compact piping layouts with high vibration exposure
• Corrosion-sensitive environments

Process Piping Systems

• Chemical handling
• Water treatment plants
• Industrial fluid transport

Why Raised Face Flanges Are Preferred

In comparison to other flange facing types:

Parameter	Raised Face (RF)	Flat Face (FF)	Ring Type Joint (RTJ)
Sealing Efficiency	High	Moderate	Very High
Pressure Range	Medium to High	Low	High to Extreme
Gasket Type	Soft / Semi-metallic	Full-face soft	Metal ring
Installation Sensitivity	Moderate	Low	High
Cost & Complexity	Balanced	Low	High

Engineering Preference of RF Flanges

Raised Face Flanges are preferred because they:

• Provide localized gasket compression, improving sealing reliability
• Support a wide range of gasket materials
• Offer balanced performance between cost and pressure capability
• Are less sensitive to installation errors compared to RTJ
• Avoid flange distortion risks associated with flat face systems

Sealing Advantages in Moderate to High Pressure

The raised face geometry enables:

• Concentration of bolt load onto a smaller gasket area
• Increased gasket seating stress
• Improved sealing under internal pressure fluctuations

This makes RF flanges suitable for:

• Class 150 to Class 1500 systems (typical)
• Hydrocarbon service
• Steam and thermal systems

2. Technical Definition of Raised Face Flanges

Engineering Definition

A Raised Face Flange (RF Flange) is defined as:

A pressure-retaining bolted flange connection featuring a raised sealing surface above the bolt circle, designed to concentrate gasket compression and enhance sealing performance under pressure.

Key Design Characteristics

Raised Sealing Surface

• Elevated above flange face
• Machined to controlled surface finish
• Ensures focused gasket compression

Bolt Circle

• Located outside sealing area
• Transfers preload force to gasket

Gasket Compatibility

• Spiral wound gaskets
• Compressed asbestos-free (CAF)
• PTFE gaskets
• Graphite-based gaskets

Raised Face Height

Raised face height varies with pressure class:

ASME Class	Raised Face Height
Class 150 / 300	1.6 mm (1/16”)
Class 400 and above	6.4 mm (1/4”)

Engineering Logic

• Lower classes require less gasket stress
• Higher classes require deeper engagement and load concentration

RF vs Flat Face vs RTJ (Engineering Comparison)

Flat Face (FF)

• Entire flange surface in contact
• Used for low-pressure systems
• Risk of bending stress in bolting

Raised Face (RF)

• Partial contact area (gasket region only)
• Improved sealing efficiency
• Balanced stress distribution

Ring Type Joint (RTJ)

• Metallic ring gasket seated in groove
• Used for extreme pressure/temperature
• Requires precise machining and alignment

Applicable Design Standards

Raised Face Flanges are governed by:

• ASME B16.5 – NPS ½” to 24”
• ASME B16.47 Series A & B – NPS 26” to 60”

These standards define:

• Dimensions
• Pressure-temperature ratings
• Facing types
• Tolerances

3. Engineering & Sealing Principle

Gasket Seating Stress Concentration

The primary function of the raised face is to:

• Reduce gasket contact area
• Increase compressive stress per unit area

Effect

Higher stress improves:

• Micro-sealing at surface irregularities
• Resistance to fluid leakage

Bolt Preload Mechanics

Bolting generates the required sealing force.

Mechanism

1. Bolts are tightened → tensile load generated
2. Flanges compress gasket
3. Gasket deforms elastically/plastically
4. Seal is established

Critical Engineering Requirement

Bolt preload must exceed:

• Internal pressure forces
• Gasket relaxation losses

Contact Pressure Distribution

In RF flanges:

• Pressure is concentrated within the raised face
• Uniform distribution is essential

Factors Affecting Distribution

• Surface finish
• Bolt tightening sequence
• Flange flatness
• Gasket type

Surface Finish Impact (Serration)

Typical finish: 125–250 AARH (Arithmetic Average Roughness Height)

Function of Serrations

• Create micro-grooves
• Improve gasket grip
• Prevent gasket slippage

Types

• Concentric serration
• Spiral serration

Leakage Prevention Mechanism

Leakage is prevented through:

• Gasket compression exceeding internal pressure force
• Elastic recovery maintaining seal during load changes

Failure Modes Prevented

• Blowout
• Micro-leakage
• Thermal relaxation leaks

Elastic Recovery of Gasket

After compression:

• Gasket stores elastic energy
• Compensates for:
  • Temperature changes
  • Pressure fluctuations
  • Bolt relaxation

Flange Rotation Under Load

Under internal pressure:

• Flanges tend to rotate outward
• Reduces gasket pressure at inner diameter

RF Design Advantage

• Maintains sealing despite minor rotation
• Improved compared to flat face

Bolt Stress vs Internal Pressure Relationship

Force Balance Concept

Internal pressure creates separating force:

• Acts on pipe cross-sectional area

Bolts must provide:

• Equal or greater compressive force

Engineering Condition

   

4. Pressure & Load Engineering

ASME Pressure Classes

Raised Face Flanges are available in:

• Class 150
• Class 300
• Class 600
• Class 900
• Class 1500
• Class 2500

Interpretation

Class rating defines:

• Pressure-temperature capability
• Structural strength

Internal Pressure vs Gasket Stress

Requirement

Gasket stress must exceed:

• Internal pressure
• Fluid penetration forces

Engineering Balance

• Excess stress → gasket damage
• Insufficient stress → leakage

External Loads

Flanges are subjected to:

Piping Loads

• Axial forces
• Bending moments
• Torsional loads

Thermal Expansion

• Induces stress in bolted joints

Vibration

• Cyclic loading leading to fatigue

Flange Stress Categories

1. Longitudinal Stress

• Along flange axis
• Due to axial loads

2. Radial Stress

• From internal pressure
• Acts outward

3. Circumferential (Hoop) Stress

• Around flange circumference
• Critical for structural integrity

Fatigue & Cyclic Loading

Repeated loading leads to:

• Bolt relaxation
• Micro-cracking
• Gasket degradation

Mitigation

• Proper torque control
• High-quality materials
• Controlled installation

Safety Factor Philosophy

Design incorporates:

• Material strength margin
• Load uncertainty allowance
• Environmental degradation

Typical Approach

• Conservative preload
• Verified via standards

Structural Integrity Considerations

• Flange thickness vs pressure
• Hub design (for weld neck RF)
• Bolt strength class
• Gasket selection

Dimensional & Design Logic

Raised Face Geometry

Critical parameters:

• Height
• Diameter
• Surface finish

Bolt Circle Diameter

Defines:

• Load distribution
• Bolt spacing
• Torque uniformity

Flange Thickness

Determined by:

• Pressure class
• Material strength
• Stress limits

Hub Geometry (Weld Neck RF Flanges)

Provides:

• Smooth stress transition
• Reduced turbulence
• Improved fatigue resistance

Facing Types

Stock Finish

• General-purpose
• Widely used

Spiral Serrated

• Continuous spiral groove
• Enhanced sealing

Concentric Serrated

• Independent grooves
• Suitable for softer gaskets

Machining Tolerances

Critical for:

• Proper alignment
• Load distribution
• Leak prevention

Flatness & Parallelism

Ensures:

• Uniform gasket compression
• Reduced leakage risk

5. Applicable Standards (ASME / ASTM / DIN / EN / ISO)

ASME Dimensional & Design Standards

ASME B16.5

Applies to:

• NPS ½” to 24”
• Pressure Classes: 150 to 2500

Defines:

• Flange dimensions
• Raised face geometry
• Bolt circle and drilling
• Facing types (RF, FF, RTJ)
• Pressure-temperature ratings

ASME B16.47

Applies to:

• NPS 26” to 60”

Divided into:

• Series A (based on MSS SP-44)
• Series B (based on API 605)

Engineering Difference

Parameter	Series A	Series B
Flange Thickness	Higher	Lower
Bolt Circle	Larger	Smaller
Bolt Size	Larger	Smaller
Weight	Higher	Lower
Application	High integrity systems	Economical large diameter

ASTM Material Standards

Material specifications for Raised Face Flanges are governed by ASTM standards:

Carbon Steel

• ASTM A105 – Forged carbon steel for ambient and high-temperature service
• ASTM A350 LF2 – Low-temperature carbon steel

Stainless Steel

• ASTM A182 F304 / F304L
• ASTM A182 F316 / F316L

Alloy Steel

• ASTM A182 F11 (Cr-Mo steel)
• ASTM A182 F22 (higher temperature capability)

Duplex / Super Duplex

• ASTM A182 F51 / F53

DIN / EN Standards (Comparison Context)

DIN EN 1092-1

Defines:

• PN pressure ratings (PN10, PN16, PN25, PN40, PN63, PN100)
• Flange dimensions and facing types

Comparison with ASME

Parameter	ASME System	EN System
Pressure Classification	Class (150–2500)	PN (10–100)
Units	Imperial-based	Metric-based
Facing	RF, RTJ, FF	Type B (RF equivalent)

ISO Standards

Relevant ISO standards:

• ISO 7005 – Metallic flange systems
• ISO 15649 – Piping design

Used in:

• International EPC projects
• Cross-standard procurement

Standard Mapping to Service Conditions

Standard	Application	Pressure Range	Temperature Range
ASME B16.5	General process piping	Medium to high	Wide
ASME B16.47	Large diameter pipelines	Medium to high	Moderate
EN 1092-1	European systems	Low to high	Moderate
ISO	Global harmonization	Varies	Varies

6. Material & Grade Options

Material selection for Raised Face Flanges is based on:

• Pressure
• Temperature
• Corrosion environment
• Mechanical loads

Carbon Steel Flanges

ASTM A105

• Standard forged carbon steel
• Suitable for ambient to high temperature

Characteristics:

• Good strength
• Cost-effective
• Limited corrosion resistance

ASTM A350 LF2

• Designed for low-temperature service

Characteristics:

• Improved toughness
• Impact-tested (Charpy V-notch)
• Suitable for sub-zero conditions

Stainless Steel Flanges

ASTM A182 F304

• General corrosion resistance
• Suitable for water, mild chemicals

ASTM A182 F316

• Enhanced resistance due to molybdenum
• Suitable for chloride environments

Alloy Steel Flanges

F11 (Cr-Mo Steel)

• Elevated temperature service
• Used in power plants

F22

• Higher creep resistance
• Suitable for high-pressure steam systems

Duplex & Super Duplex

F51 (Duplex)

• High strength
• Good corrosion resistance

F53 (Super Duplex)

• Excellent resistance to:
  • Chlorides
  • Seawater
  • Aggressive chemicals

Material Comparison Table

Grade	Yield Strength (MPa)	Tensile Strength (MPa)	Temperature Range	Corrosion Resistance	Typical Application
A105	~250	485–620	-29°C to 425°C	Low	Oil & gas pipelines
A350 LF2	~250	485–620	-46°C to 345°C	Low	Cryogenic systems
F304	~205	515–620	-196°C to 870°C	Moderate	Water, food industry
F316	~205	515–620	-196°C to 870°C	High	Marine, chemical
F11	~275	415–585	Up to 540°C	Moderate	Power plants
F22	~415	585–760	Up to 600°C	Moderate	High-pressure steam
F51	~450	620–880	-50°C to 300°C	High	Offshore
F53	~550	750–950	-50°C to 300°C	Very High	Seawater systems

7. Heat Treatment Information

Heat treatment is essential for achieving required mechanical properties and structural stability.

Normalizing

• Heating above critical temperature
• Air cooling

Effect:

• Refines grain structure
• Improves uniformity

Quenching & Tempering (Q&T)

• Rapid cooling (quenching)
• Followed by tempering

Effect:

• Increased strength
• Controlled toughness

Solution Annealing (Stainless Steel)

• Heating to high temperature
• Rapid cooling

Effect:

• Dissolves carbides
• Restores corrosion resistance

Stress Relieving

• Heating below transformation temperature

Effect:

• Reduces residual stresses
• Improves dimensional stability

Mechanical Property Impact

Property	Effect of Heat Treatment
Grain Structure	Refined and uniform
Strength	Increased (Q&T)
Toughness	Improved
Hardness	Controlled
Residual Stress	Reduced

Hardness Ranges (Typical)

Material	Hardness (HB)
A105	120–187
LF2	120–200
F304	150–200
F316	150–200
F22	180–250

Impact Testing (Charpy V-Notch)

Required for:

• Low-temperature service
• Critical applications

Ensures:

• Resistance to brittle fracture
• Material toughness

8. Manufacturing Process

Manufacturing of Raised Face Flanges follows controlled, traceable steps.

Raw Material Inspection

• Chemical composition verification
• Mechanical property certification
• Traceability check

Forging

• Open-die or closed-die forging
• Grain flow alignment

Objective:

• Eliminate internal defects
• Improve strength

Ring Rolling (If Applicable)

Used for larger diameters:

• Improves grain orientation
• Reduces material waste

CNC Machining

• Turning of OD/ID
• Facing operations
• Drilling bolt holes

Ensures:

• Dimensional accuracy
• Surface finish control

Raised Face Machining

• Precision machining of RF surface
• Controlled height and flatness

Serration Finishing

• Spiral or concentric grooves
• Controlled AARH

Drilling

• Bolt holes machined as per standards
• Angular accuracy maintained

Heat Treatment

Performed as per material specification:

• Furnace controlled
• Temperature monitored

Surface Coating

Applied based on service requirement:

• Anti-corrosion protection
• Handling safety

Final Inspection

• Dimensional checks
• Visual inspection
• Surface verification

Marking & Traceability

Includes:

• Material grade
• Heat number
• Size
• Pressure class
• Manufacturer identification

Traceability maintained from:

• Raw material → Finished flange

9. Surface Finish Options

Protective Coatings

Anti-Rust Oil

• Temporary protection
• Used for carbon steel

Black Oxide

• Mild corrosion resistance
• Improved appearance

Zinc Plating

• Moderate corrosion resistance
• Suitable for non-critical environments

Hot-Dip Galvanizing

• Thick zinc layer
• Suitable for outdoor and humid environments

PTFE Coating

• Chemical resistance
• Low friction

Passivation (Stainless Steel)

• Removes free iron
• Enhances corrosion resistance

Surface Roughness

Parameters

• Ra (Roughness Average)
• AARH (Arithmetic Average Roughness Height)

Typical RF finish:

• 125–250 AARH

Impact on Sealing

Surface finish influences:

• Gasket grip
• Micro-sealing
• Leak resistance

Engineering Balance

• Too smooth → gasket slip
• Too rough → gasket damage

Dimensional Engineering Tables

The following table represents typical dimensional characteristics of Raised Face Flanges as per ASME B16.5 (indicative values; project-specific verification required).

Dimensional Table (RF Flanges)

NPS	Flange OD (mm)	Bolt Circle (mm)	No. of Bolts	Bolt Size	RF Height (mm)	Thickness (mm)
1/2”	89	60.3	4	M16	1.6	9.6
1”	108	79.4	4	M16	1.6	11.2
2”	152	120.7	4	M16	1.6	17.5
4”	229	190.5	8	M16	1.6	23.9
6”	279	241.3	8	M20	1.6	25.4
8”	343	298.5	8	M20	1.6	28.6
10”	406	362.0	12	M24	1.6	30.2
12”	483	431.8	12	M24	1.6	31.8
16”	597	539.8	16	M27	1.6	36.6
20”	711	635.0	20	M30	1.6	41.3
24”	813	749.3	20	M33	1.6	46.1

Engineering Notes

• RF height increases to 6.4 mm for higher pressure classes
• Bolt size and count increase with pressure rating
• Thickness is directly linked to pressure class and allowable stress

10. Pressure–Temperature Rating Table

Pressure ratings for Raised Face Flanges are governed by ASME material groupings and temperature derating factors.

Typical Pressure Ratings (Carbon Steel – ASTM A105)

Class	38°C (psi)	200°C (psi)	400°C (psi)
150	285	260	200
300	740	680	520
600	1480	1360	1040
900	2220	2040	1560
1500	3705	3400	2600
2500	6170	5660	4300

Engineering Interpretation

• Pressure capacity decreases with temperature
• Material strength governs allowable stress
• Design must consider maximum operating temperature

Bolt Torque Chart

Torque values are critical for achieving correct gasket seating stress.

Torque Values (Indicative)

Material: ASTM A193 B7 Bolting

Bolt Size	Torque (Nm) – Dry	Torque (Nm) – Lubricated
M16	210	160
M20	410	310
M24	710	530
M27	1050	780
M30	1450	1080
M33	1950	1450
M36	2550	1900

For Metric Property Classes

Class 8.8

Bolt Size	Torque (Nm)
M16	180
M20	360
M24	620
M30	1250

Class 10.9

Bolt Size	Torque (Nm)
M16	260
M20	520
M24	900
M30	1800

Engineering Considerations

• Lubrication reduces friction → lower torque required
• Torque must be applied in controlled stages
• Over-tightening may:
  • Crush gasket
  • Yield bolts

11. Preload Calculation Guide

Bolt Load Requirement

The total bolt load must satisfy:

   

Where:

• (F_b) = Bolt preload force
• (F_i) = Internal pressure force
• (F_g) = Gasket seating force

Internal Pressure Force

   

Where:

• (P) = Internal pressure
• (A) = Effective gasket area

Gasket Seating Stress

   

Where:

• (y) = Gasket seating stress
• (A_g) = Gasket contact area

Bolt Stress Relationship

   

Where:

• (\sigma_b) = Bolt stress
• (A_b) = Bolt cross-sectional area

Sample Calculation

Given:

• Pressure (P = 2 , MPa)
• Gasket area (A = 0.01 , m^2)
• Gasket factor (y = 30 , MPa)

Step 1: Internal Force

   

Step 2: Gasket Force

   

Step 3: Total Required Bolt Load

   

Safety Margin Logic

• Add 10–30% margin for:
  • Relaxation
  • Temperature effects
  • Installation variability

Mechanical Properties Table

Material	Yield Strength (MPa)	Tensile Strength (MPa)	Hardness (HB)	Elongation (%)
A105	250	485–620	120–187	≥20
LF2	250	485–620	120–200	≥22
F304	205	515–620	150–200	≥30
F316	205	515–620	150–200	≥30
F11	275	415–585	130–200	≥20
F22	415	585–760	180–250	≥18
Duplex F51	450	620–880	230–290	≥25

Corrosion Resistance Table

Material	Marine	Acidic	Hydrocarbon	Humid
Carbon Steel (A105)	Poor	Poor	Good	Poor
SS304	Moderate	Moderate	Good	Good
SS316	Good	Good	Good	Excellent
Duplex (F51)	Excellent	Good	Excellent	Excellent
Alloy Steel (F11/F22)	Moderate	Poor	Excellent	Moderate

Inspection & Quality Control

Inspection of Raised Face Flanges ensures compliance with design, material, and performance requirements.

Positive Material Identification (PMI)

• Verifies alloy composition
• Ensures correct grade selection

Ultrasonic Testing (UT)

• Detects internal defects
• Identifies:
  • Voids
  • Inclusions
  • Cracks

Magnetic Particle Inspection (MPI)

• Surface and near-surface defect detection
• Applicable to ferromagnetic materials

Dye Penetrant Inspection (DPI)

• Detects surface cracks
• Suitable for stainless steel

Hydrostatic Testing

• Applied where applicable (assembled systems)
• Validates pressure integrity

Dimensional Inspection

Verification of:

• OD / ID
• Bolt circle
• Hole alignment
• RF height

Surface Finish Inspection

• AARH measurement
• Serration verification

Hardness Testing

• Confirms heat treatment effectiveness
• Prevents over-hardening

Third-Party Inspection

Conducted by:

• Independent inspection agencies

Ensures:

• EPC compliance
• Project acceptance

Certification

EN 10204 3.1

• Manufacturer-certified test report

EN 10204 3.2

• Third-party verified certification

Includes:

• Chemical composition
• Mechanical properties
• Heat treatment records
• Inspection results

Traceability System

Each flange is traceable through:

• Heat number
• Batch number
• Material certificate
• Inspection reports

Traceability ensures:

• Audit compliance
• Failure investigation capability
• Lifecycle documentation

Industries Served

Raised Face Flanges are deployed across critical infrastructure where pressure integrity, sealing reliability, and compliance with international standards are mandatory.

Oil & Gas Industry

Upstream (Exploration & Production)

• Wellhead piping systems
• Flowlines and gathering systems
• High-pressure choke and kill lines

Midstream (Transportation)

• Crude oil pipelines
• Gas transmission systems
• Compressor stations

Downstream (Refining)

• Distillation units
• Hydroprocessing units
• Utility piping systems

Engineering Requirement:

• Resistance to pressure fluctuations
• Compatibility with hydrocarbon fluids
• High structural integrity under cyclic loads

Petrochemical Industry

• Polymer processing units
• Chemical reactors
• Solvent transfer systems

Material Selection Drivers:

• Corrosion resistance
• Chemical compatibility
• Temperature endurance

Refineries

• High-temperature process piping
• Vacuum systems
• Sulfur recovery units

Critical Considerations:

• Thermal expansion
• Corrosive media
• Continuous operation conditions

Power Generation

Thermal Power Plants

• Steam lines (HP/HT)
• Boiler feedwater systems

Nuclear & Combined Cycle Plants

• Auxiliary piping
• Cooling systems

Engineering Focus:

• Creep resistance (alloy steels)
• High-temperature stability
• Pressure containment

LNG & Cryogenic Systems

• Liquefied natural gas handling
• Storage and regasification

Material Requirements:

• Low-temperature toughness
• Impact-tested materials (e.g., LF2, stainless steel)

Offshore Platforms

• Compact piping configurations
• High vibration and dynamic loading

Environmental Exposure:

• Marine corrosion
• Salt-laden atmosphere

Chemical Processing Plants

• Acid handling systems
• Alkali processing
• Specialty chemical lines

Key Factors:

• Corrosion resistance
• Leak prevention
• Material compatibility

12. Export Capability & Global Supply

Super Industries supplies Raised Face Flanges to international EPC projects with structured export systems aligned to project documentation and logistics requirements.

Global Supply Regions

• USA – ASME-compliant projects
• Europe – EN / PED-aligned systems
• Middle East – Oil & gas EPC projects
• Southeast Asia – Refinery and infrastructure development

Export Packaging

Packaging is designed to prevent:

• Mechanical damage
• Corrosion during transit
• Contamination of sealing surfaces

Typical Methods

• Wooden crates (fumigated)
• Palletized loads
• Individual flange protection caps
• VCI (Vapor Corrosion Inhibitor) wrapping

Documentation Package

Each shipment includes:

• Commercial invoice
• Packing list
• Mill test certificates (EN 10204 3.1 / 3.2)
• Inspection reports (NDT, dimensional)
• Heat treatment records
• Material traceability documents

Project Logistics

• Batch-wise dispatch for large EPC orders
• Containerized shipment (FCL/LCL)
• Marking aligned with project tagging systems

Compliance Support

• Third-party inspection coordination
• Client-specific documentation formats
• Code compliance (ASME, EN, ISO)

Procurement & Installation View

Gasket Selection

Selection depends on:

• Pressure class
• Temperature
• Fluid type

Common Gasket Types

• Spiral wound gasket (metal + filler)
• PTFE gasket
• Compressed fiber gasket

Bolt Tightening Sequence

Proper tightening sequence is critical to ensure uniform gasket compression.

Cross Pattern (Star Pattern)

1. Initial snug tightening
2. Progressive torque application
3. Final torque verification

Objective:

• Prevent flange distortion
• Ensure uniform stress distribution

Torque Application Stages

Typical tightening sequence:

• Stage 1: 30% of final torque
• Stage 2: 60% of final torque
• Stage 3: 100% torque
• Stage 4: Final circular pass

Re-Tightening Requirement

Re-tightening may be required:

• After initial pressurization
• After thermal cycles

Reason:

• Gasket creep
• Bolt relaxation

Installation Checkpoints

Before installation:

• Verify flange facing condition
• Check gasket integrity
• Confirm bolt grade and lubrication

During installation:

• Ensure alignment
• Avoid flange forcing

After installation:

• Leak testing
• Torque verification

Storage Guidelines

To maintain integrity of Raised Face Flanges:

• Store in dry, covered areas
• Protect raised face from damage
• Avoid direct ground contact
• Apply rust preventive coatings

13. Custom Engineering Capabilities

Super Industries supports project-specific requirements beyond standard specifications.

Non-Standard Sizes

• Large diameter RF flanges beyond standard range
• Custom thickness and bolt configurations

Special Facing Requirements

• Modified raised face dimensions
• Custom serration profiles
• Precision surface finish control

High-Pressure Custom RF Flanges

• Designed for Class 1500 / 2500 systems
• Reinforced geometry
• Enhanced bolting arrangements

Project-Specific Machining

• Special tolerances
• Matching equipment interfaces
• Custom drilling patterns

Marking & Traceability

• Project-specific tagging
• Heat number traceability
• Barcode / identification systems

Quality Assurance & Project Compliance

Manufacturing Discipline

• Controlled forging processes
• CNC machining precision
• Documented heat treatment cycles

Inspection Integration

• In-process inspection checkpoints
• Final inspection before dispatch
• Third-party witness inspection

Documentation Integrity

• Complete traceability records
• Test reports aligned with standards
• Audit-ready documentation

EPC Project Readiness

The manufacturing and documentation systems support:

• Technical bid evaluations
• Vendor qualification processes
• Consultant review compliance

Engineering Summary

Raised Face Flanges represent a balanced solution in pressure piping systems, offering:

• Controlled gasket compression
• Reliable sealing performance
• Compatibility with multiple gasket types
• Suitability across medium to high-pressure applications

Their design integrates:

• Bolt preload mechanics
• Surface finish optimization
• Pressure-temperature rating compliance
• Material-specific performance characteristics

Conclusion

Super Industries manufactures Raised Face Flanges with a focus on:

• ASME-compliant dimensional accuracy
• Material traceability and certification
• Controlled manufacturing processes
• Inspection and testing aligned with EPC requirements

The technical approach integrates:

• Engineering design discipline
• Pressure system understanding
• Sealing performance reliability
• Documentation readiness for global projects

Final Engineering Position

From an EPC evaluation perspective:

• The flange design aligns with ASME pressure system requirements
• Manufacturing processes reflect controlled industrial practice
• Inspection and documentation support third-party verification
• Material and design selections are suitable for critical service applications

Raised Face Flanges produced under such systems are appropriate for inclusion in:

• Oil & gas infrastructure
• Power generation projects
• Petrochemical facilities
• International EPC contracts