1. **What grade is seamless pipe?**
Seamless pipes are available in various grades depending on the material and application. Common grades include:
- **Carbon steel**: ASTM A106 Gr B, ASTM A53 Gr B, API 5L X42-X80.
- **Stainless steel**: ASTM A312 TP304/316.
- **Alloy steel**: ASTM A335 P11/P22.
The specific grade depends on mechanical properties, temperature, pressure, and corrosion resistance requirements.
2. **Is ASTM A53 seamless pipe?**
ASTM A53 covers both welded and seamless pipes. Only **Type S** (seamless) under ASTM A53 is seamless. Types E (electric-resistance welded) and F (furnace-welded) are welded. Always check the specification type.
3. **Is A106 pipe seamless?**
Yes, **ASTM A106** is a standard specification for **seamless carbon steel pipe** designed for high-temperature service (e.g., boilers, refineries). All A106 pipes are seamless.
4. **What is the ASME Code for seamless pipe?**
The ASME Boiler and Pressure Vessel Code (BPVC) and ASME B36.10M/B36.19M cover seamless pipe standards. Key sections:
- **ASME B36.10M**: Dimensions for carbon/alloy steel seamless pipes.
- **ASME B36.19M**: Dimensions for stainless steel seamless pipes.
- **ASME BPVC Section II**: Material specifications.
5. **Difference between ASME B16.20 and B16.21?**
- **ASME B16.20**: Covers **metallic gaskets** (e.g., spiral-wound, ring-joint) for pipe flanges, typically used in high-pressure/temperature applications.
- **ASME B16.21**: Specifies **non-metallic flat gaskets** (e.g., rubber, fiber) for low-pressure/temperature flange connections.
B16.20 focuses on metal gaskets for rigorous conditions; B16.21 addresses non-metallic gaskets for simpler applications.
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