Investment Casting Union
What are Investment Casting Union?
A Union is a precision-made pipe fitting manufactured using the investment casting process. It is designed to connect two pipes or components and allows for easy disassembly without disturbing the rest of the system. Unions are ideal for installations that require frequent maintenance, inspection, or replacement.
Unlike permanent joints, unions provide a reusable, leak-proof connection, making them highly suitable for instrumentation systems, food-grade units, chemical pipelines, and marine environments where hygiene, accessibility, and precision matter.
Key Features
- Three-Piece Construction – Enables secure, yet detachable connections.
- Multiple Seat Types – Available with flat, beveled, or metal-to-metal sealing faces.
- Corrosion Resistant – Suitable for aggressive and sanitary environments.
- Investment Casting Quality – Smooth finish, tight tolerances, and uniform geometry.
- Complies with International Standards – Built as per ASME, DIN, MSS-SP, and ISO guidelines.
Specifications
Mechanical Properties
Chemical Composition
Equivalent Grades
Weight Chart
Specifications
| Parameter | Details |
|---|---|
| Sizes | ¼" to 4" (DN8 – DN100) |
| Connection Types | BSP/NPT Threads, Socket Weld, Butt Weld |
| Seat Type | Flat / Beveled / Metal-to-Metal |
| Material Options | SS 304, SS 316, CF8M, Duplex, Super Duplex |
| Standards | ASME B16.11, ISO 4144, MSS-SP-95, DIN 2950 |
| Manufacturing | Investment Casting + Machining (CNC finished) |
| Property | Typical Value |
|---|---|
| Tensile Strength | 485 – 750 MPa |
| Yield Strength | 205 – 450 MPa |
| Elongation | 20% – 30% |
| Hardness | 125 – 250 HB |
| Temperature Range | -46°C to +600°C |
| Element | Composition (%) |
|---|---|
| Carbon (C) | ≤ 0.08 |
| Manganese (Mn) | ≤ 2.00 |
| Silicon (Si) | ≤ 1.00 |
| Chromium (Cr) | 18.0 – 20.0 |
| Nickel (Ni) | 8.0 – 14.0 |
| Molybdenum (Mo) | 2.0 – 3.0 (for 316/CF8M) |
| Phosphorus (P) | ≤ 0.040 |
| Sulfur (S) | ≤ 0.030 |
| Iron (Fe) | Balance |
| Standard | Equivalent Grades |
|---|---|
| ASTM | A351 CF8 / CF8M, A743 / A744 |
| ASME | B16.11 |
| MSS-SP | SP-95 |
| DIN | 2950 / 2955 |
| ISO | ISO 4144 |
| Union Type | Size (inches) | Weight per 100 pcs (kg) |
|---|---|---|
| Flat Seat Union | 1" | 14.20 |
| Beveled Seat Union | 1½" | 18.60 |
| Metal Seat Union | 2" | 23.40 |
Applications of Investment Casting Union
Construction &
Infrastructure
Automotive & Heavy
Equipment
Manufacturing &
Fabrication
Medical & Laboratory
Equipment
Electrical &
Electronics Assembly
Oil, Gas & Petrochemical
Installations
Do you have questions?
What’s the purpose of using a union over a coupling?
Unions allow disassembly without rotating the pipes, making them ideal for maintenance-intensive systems.
Are unions available with different end connections?
Yes. They can be supplied with socket weld, threaded, or butt weld ends, based on your application.
Can unions be pressure tested and certified?
Absolutely. We provide MTCs, hydro test reports, and third-party inspections.
Are unions corrosion-resistant for marine use?
Yes. Our SS 316/CF8M and Duplex options perform well in saltwater and aggressive environments.
