**1. What is the difference between ASTM F876 and F877?**
ASTM F876 and F877 are both standards for crosslinked polyethylene (PEX) tubing, but they focus on different aspects.
* **ASTM F876** is the **Standard Specification for Crosslinked Polyethylene (PEX) Tubing**. This standard defines the basic material properties, dimensions, performance requirements, and test methods for the PEX tubing itself. It covers things like minimum burst pressure, hydrostatic sustained pressure strength, and chemical resistance.
* **ASTM F877** is the **Standard Specification for Crosslinked Polyethylene (PEX) Plastic Hot- and Cold-Water Distribution Systems**. This standard builds upon F876. It specifies the requirements for PEX tubing that is intended specifically for use in potable water distribution systems. It includes all the requirements of F876 but adds critical performance tests for the end-use application, such as chlorine resistance, oxidative stability in hot water, and fittings pull-out resistance.
In short: **F876 defines the *tube*, while F877 defines the *system* (the tube for potable water applications).** A product meeting F877 automatically meets the requirements of F876 for the tubing.
**2. What is ASTM D4806?**
ASTM D4806 is the **Standard Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel**. This standard sets the requirements for ethanol that is intended to be blended with gasoline (typically up to 10% or 15%) for use in most common vehicles. It specifies purity levels and limits for contaminants like water, chloride ions, copper, and acidity to ensure the fuel is safe for engines and fuel systems and performs reliably.
**3. Where can I get ASTM standards?**
ASTM standards are copyrighted documents and are not available for free. The primary and official source to obtain them is from the **ASTM International website** (www.astm.org). You can purchase individual standards or subscribe to a collection for online access. Many universities, technical libraries, and corporate libraries provide free access to their members through an ASTM Standards subscription. Some third-party technical document websites may also sell them, but it is always best to use the official ASTM source to ensure you have the most current, official version.
**4. Are ASME standards free?**
No, ASME standards are not free. Like ASTM standards, they are copyrighted documents. They must be purchased from the **American Society of Mechanical Engineers (ASME)** or from authorized distributors. The revenue from sales funds the ongoing development, maintenance, and updating of these important technical standards. You can buy them on the ASME website (www.asme.org).
**5. Which countries use ASME standards?**
ASME standards, particularly the ASME Boiler and Pressure Vessel Code (BPVC), are used **globally**. While they are American standards, their influence is international due to their reputation for safety and engineering excellence. They are adopted and used by many countries and industries around the world. Key examples include:
* **United States** and **Canada** (often incorporated into law).
* Countries in **Asia**, such as South Korea, Japan, and China, especially for power generation and petrochemical projects.
* Many countries in the **Middle East** and **South America** for major construction and oil & gas projects.
* Many other nations use ASME codes as a basis for their own national regulations or accept them for imported equipment.
Essentially, any country involved in major manufacturing, power generation, or oil and gas refining is likely to use ASME standards.
