DN25 Pressure Rating 150LB Pipe Installation Nickel Alloy Flanges ASME B16.5

For a DN25 (Diameter Nominal 25 mm, approximately 1 inch) pressure rating of 150# (150 pounds) according to ASME B16.5 standards, using a nickel alloy material for flanges, several specific details need to be considered for proper specification and application. These details encompass dimensions, material grade, design considerations, and applicable standards, particularly tailored to nickel alloy flanges at this specific size and pressure class.

Dimensions and Design

• Size: DN25, approximately equivalent to NPS 1 inch, specifies the nominal diameter of the flange.
• Pressure Rating: 150# indicates a flange designed to handle a maximum pressure of 150 psi at a certain temperature range, according to ASME B16.5.
• Flange Type: Weld neck flanges, characterized by their long tapered hub, are designed for butt welding to a piping system, offering strength and reducing stress concentrations.
• Facing: Typically, weld neck flanges for this rating come with a raised face (RF), which is the most common facing type. The raised face adds additional material to the flange end, concentrating more pressure on a smaller area, enhancing the seal's effectiveness.
• Bolt Circle & Number of Bolts: For a DN25, 150# weld neck flange, the bolt circle diameter and the number of bolts will be specified in accordance with ASME B16.5 standards. Typically, this would involve 4 bolts.

Material Specification

• Nickel Alloy: The term "nickel alloy" encompasses a broad group of alloys. Common nickel alloys for flanges include Inconel (e.g., 625, 718), Monel (e.g., 400, K500), Hastelloy (e.g., C276, C22), and Incoloy (e.g., 800, 825). The specific material grade will be chosen based on the anticipated service conditions, such as temperature, pressure, and corrosive media.
• Corrosion Resistance: Nickel alloys are selected for their excellent corrosion resistance, particularly in high-temperature, high-pressure, and corrosive environments.
• Mechanical Properties: High strength, durability, and resistance to thermal expansion are key characteristics of nickel alloys, making them ideal for various industrial applications, including oil and gas, chemical processing, and power generation.

ASME B16.5 Standards

• Dimensional Standards: ASME B16.5 provides all the required dimensions, including the outer diameter, thickness, bolt circle diameter, and number of bolt holes, for weld neck flanges of DN25 size with a 150# pressure rating.
• Material Standards: While ASME B16.5 specifies dimensions and designations, the material specifications (for nickel alloys, in this case) would be guided by other standards such as ASTM B564, which covers nickel alloy forgings for flanges, fittings, and other pressure components.
• Testing and Inspection: ASME standards will require specific testing and quality assurance measures to ensure the flange's integrity and compatibility with the intended service environment.

When specifying a DN25, 150# ASME B16.5 nickel alloy flange, it's crucial to consider all these factors comprehensively. The selection of the appropriate nickel alloy grade, understanding the service environment, and adherence to ASME standards and guidelines will ensure the flange's performance and longevity in its intended application.