Space-saving Flanges For Corrosion-resistant Pipeline Connections
Compact flanges offer space-saving, leak-proof connections for high-pressure industrial piping.
Space-saving Flanges For Corrosion-resistant Pipeline Connections
Compact flanges offer space-saving, leak-proof connections for high-pressure industrial piping. designed for corrosion resistance, they ensure durability in boiler pipeline protection and harsh environments.
Compact Flange is an advanced, space-saving flange designed for industrial piping systems requiring high-pressure and high-temperature performance. Compliant with standards like NORSOK L-005 and ISO 27509, these flanges provide superior corrosion resistance and leak-proof connections, making them ideal for boiler pipeline protection, offshore platforms, and subsea applications. Constructed from materials such as carbon steel (ASTM A105), stainless steel (A182 F316L), or high-yield alloys (A694 F60), they are engineered for durability in harsh environments like oil and gas, petrochemical, and power generation industries.
The compact flange features a unique design with a reduced diameter and fewer bolts compared to traditional ASME B16.5 flanges, resulting in a lighter and more cost-effective solution. Available in sizes from 1/2” to 48” and pressure ratings up to 15,000 psi, they support ring-type joint (RTJ) or IX seal ring configurations for enhanced sealing. Surface treatments like 3LPE, PTFE, or galvanizing further improve corrosion resistance, ensuring reliability when handling corrosive fluids or gases in chemical processing or marine systems.
These flanges undergo stringent testing, including hydrostatic, tensile, and non-destructive tests (ultrasonic, radiographic), to ensure compliance with NORSOK and API standards. With tensile strengths ranging from 485 MPa (A105) to 515 MPa (F316L), they excel in high-pressure conditions and temperatures from -29°C to 550°C. The compact design minimizes weight and space requirements, making them suitable for high-pressure flange applications in constrained environments like FPSO units or boiler pipeline protection in power plants.
Compared to conventional weld neck or slip-on flanges, compact flanges offer significant advantages in weight reduction (up to 80% lighter) and installation efficiency, reducing bolt torque requirements and maintenance costs. Their robust sealing mechanism, often using metal-to-metal seals, ensures zero leakage, critical for industrial piping systems handling hazardous media. They are particularly suited for subsea pipelines, LNG terminals, and refineries where space, weight, and reliability are paramount.
Compact flanges address challenges like pipeline corrosion, thermal stress, and space constraints in demanding industrial environments. Their innovative design, compliance with stringent standards, and material versatility make them a preferred choice for engineers seeking reliable, space-saving flange solutions. Whether used in high-pressure boiler systems or corrosive offshore applications, these flanges deliver exceptional performance, safety, and longevity.
| Element | ASTM A105 (%) | ASTM A182 F316L (%) |
|---|---|---|
| Carbon (C) | 0.35 max | 0.03 max |
| Manganese (Mn) | 0.60-1.05 | 2.00 max |
| Phosphorus (P) | 0.035 max | 0.045 max |
| Sulfur (S) | 0.040 max | 0.03 max |
| Silicon (Si) | 0.10-0.35 | 0.75 max |
| Chromium (Cr) | 0.30 max | 16.0-18.0 |
| Nickel (Ni) | 0.40 max | 10.0-14.0 |
| Molybdenum (Mo) | 0.12 max | 2.0-3.0 |
| Property | ASTM A105 | ASTM A182 F316L |
|---|---|---|
| Tensile Strength, min (MPa) | 485 | 515 |
| Yield Strength, min (MPa) | 250 | 205 |
| Elongation, min (%) | 22 | 30 |
| Hardness, max (HBW) | 187 | 217 |
| Feature | Compact Flange | Weld Neck Flange | Slip-On Flange |
|---|---|---|---|
| Material Type | Carbon/Stainless Steel | Carbon/Stainless Steel | Carbon/Stainless Steel |
| Connection Type | Butt Weld (Compact Design) | Butt Weld | Fillet Weld |
| Corrosion Resistance | Excellent (Material-dependent) | Excellent (Material-dependent) | Moderate (Coatings needed) |
| Applications | Subsea, Offshore, High-Pressure | High-Pressure Pipelines | Low-Pressure Systems |
| Tensile Strength (MPa) | 485-515 (min) | 485-515 (min) | 415-485 (min) |
| Weight | Up to 80% lighter | Standard | Light |
| Key Advantage | Space-saving, leak-proof | Smooth stress distribution | Cost-effective, easy install |
A lighter, stronger, and more reliable piping connection
A compact flange—also called a Hubless Flange or Type C Flange—is engineered to deliver superior strength and leak-tight performance while being much smaller and lighter than conventional flanges. Its low-profile design makes it suitable for demanding applications where space and weight savings are critical.
Up to 70% lighter than traditional flanges, ideal for offshore and confined installations.
Double sealing ensures reliable performance even under high pressure and vibration.
Excellent resistance to fatigue, thermal cycling, and harsh operating conditions.
Compact flanges provide leak-free joint integrity, environmental safety, and reduced installation costs, making them one of the most effective piping joints for modern industry.
The most common type, featuring a raised sealing surface that concentrates the bolting force on a smaller area.
Has a flat sealing surface, commonly used with cast iron flanges and for low-pressure applications.
Features a groove for metal ring gaskets (oval or octagonal), providing metal-to-metal sealing.
Features matching tongue and groove surfaces, providing self-alignment and confined gasket area.
Flange faces have to be smooth enough to ensure a tight, leak-free seal for bolted flanges.
| Flange Face Type | Flange Face Type | Flange Face Type |
|---|---|---|
| Type A: flat face | Type D: groove face | Type G: O Ring recess |
| Type B: raised face | Type E: spigot | Type H: O Ring groove |
| Type C: tongue face | Type F: recess |
| ASME B16.5 | Pipe Flanges NPS 1/2 - 24 |
| ASTM A105 | Forged Carbon Steel |
| ASTM A350 LF2 | Low-Temperature Service |
| ASTM A182 | High-Temperature Service |
| ASTM A694 | High-Pressure Transmission |
| DIN EN 1092-1 | European Standard PN 2.5-400 |
Most commonly used, forged with machined surfaces
Corrosion resistant, grades 304, 316, etc.
High-temperature and high-pressure applications
Cast iron, aluminum, brass, bronze, plastic
| Material Category | Fittings (ASTM Grade) | Flanges (ASTM Grade) | Valves (ASTM Grade) | Bolts & Nuts (ASTM Grade) |
|---|---|---|---|---|
| Carbon Steel | A234 Gr WPA | A105 | A216 Gr WCB | A193 Gr B7 A194 Gr 2H |
| A234 Gr WPB | A105 | A216 Gr WCB | ||
| A234 Gr WPC | A105 | A216 Gr WCB | ||
| Carbon Steel
Alloy (High-Temperature) |
A234 Gr WP1 | A182 Gr F1 | A217 Gr WC1 | A193 Gr B7 A194 Gr 2H |
| A234 Gr WP11 | A182 Gr F11 | A217 Gr WC6 | ||
| A234 Gr WP12 | A182 Gr F12 | A217 Gr WC6 | ||
| A234 Gr WP22 | A182 Gr F22 | A217 Gr WC9 | ||
| A234 Gr WP5 | A182 Gr F5 | A217 Gr C5 | ||
| A234 Gr WP9 | A182 Gr F9 | A217 Gr C12 | ||
| Carbon Steel
Alloy (Low-Temperature) |
A420 Gr WPL6 | A350 Gr LF2 | A352 Gr LCB | A320 Gr L7 A194 Gr 7 |
| A420 Gr WPL3 | A350 Gr LF3 | A352 Gr LC3 | ||
| Austenitic Stainless Steel | A403 Gr WP304 | A182 Gr F304 | A182 Gr F304 | A193 Gr B8 A194 Gr 8 |
| A403 Gr WP316 | A182 Gr F316 | A182 Gr F316 | ||
| A403 Gr WP321 | A182 Gr F321 | A182 Gr F321 | ||
| A403 Gr WP347 | A182 Gr F347 | A182 Gr F347 |
ASTM standards define the specific manufacturing process of the material and determine the exact chemical composition of pipes, fittings and flanges, through percentages of the permitted quantities of carbon, magnesium, nickel, etc., and are indicated by "Grade".
The usual materials of flanges include stainless steel, carbon steel, aluminum and plastic. The choice of the material largely depends on the purpose of the flange. For example, stainless steel is more durable and is necessary for heavy use. On the other hand, plastic is more feasible for use in the home because of its reasonable price and easy installation. The materials used for flanges are under the designation of the American Society of Mechanical Engineers.
The most common materials for pipe flanges (forged grades) are: ASTM A105 (carbon steel high temperature to match A53/A106/API 5L pipes), A350 Grades LF1/2/3 (carbon steel low temperature to match A333 pipes), A694 Grades F42 to F80 (high yield carbon steel to match API 5L pipe grades), ASTM A182 Grades F5 to F91 (alloy steel flanges to match A335 pipes), A182 Grade F304/316 (stainless steel flanges to match A312 SS pipes), A182 Gr. F44/F51/F53/F55 (duplex and super duplex to match A790/A928 pipes) and various nickel alloy grades (Inconel, Incoloy, Hastelloy, Monel).
The material qualities for these flanges are defined in the ASTM standards.
Metal flanges are classified from 150 to 2500 # rating for different pressure applications.
Incoloy 825 Flange
Industries Using
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