High-density polyethylene (HDPE) pipes are a critical component for various industrial, agricultural, and municipal applications due to their durability, flexibility, and resistance to corrosion. This guide provides a detailed overview of 24-inch HDPE pipe dimensions, including sizes, specifications, and relevant technical standards. Whether you’re an engineer, project manager, or contractor, understanding the specifications of 24-inch HDPE pipes is crucial for selecting the right pipe for your application, ensuring optimal performance and adherence to industry requirements. We will discuss the dimensional properties, pressure ratings, and material characteristics of these pipes in a concise, authoritative manner, accompanied by size charts and comprehensive specifications for accurate decision-making.
What are the standard dimensions for 24 HDPE pipes?
Outside diameter (OD) and inside diameter (ID) specifications
A 24-inch HDPE pipe’s wall thickness and SDR (Standard Dimension Ratio) determine its OD (outer diameter) and ID (inner diameter). Nominally, this type of pipe has a diameter of 24 inches (610 mm). The ID varies, however, the SDR value tends to impact variability. As determined by pressure rating, lower SDR numbers have greater wall thickness to maintain pressure ratings.
- SDR 17 (Pressure rating of 100 psi): An approximate wall thickness of 1.41 inches (35.81 mm) yields an approximate ID of 21.18 inches (537.97 mm).
- SDR 11 (Pressure rating of 160 psi): An approximate wall thickness of 2.18 inches (55.37 mm) yields an approximate ID of 19.64 inches (498.95 mm).
- SDR 9 (Pressure rating of 200 psi): An approximate wall thickness of 2.67 inches (67.82 mm) yields an approximate ID of 18.66 inches (474.16 mm).
The aforementioned values assure conformance to specified industry standards and applicability to intended uses as well as compliance with expected levels of encased pressure.
Wall thickness variations for different pressure ratings
The differences in wall thickness for different pressure ratings are a direct relationship with the pipe’s Standard Dimension Ratio (SDR) and pressure rating.
- SDR 11 (160 psi): Wall thickness is 2.18 inches (55.37 mm), and the inside diameter is 19.64 inches (498.95 mm). This SDR is suitable for applications where moderate pressure tolerance is needed.
- SDR 9 (200 psi): Wall thickness increases to 2.67 inches (67.82 mm) leading to an inside diameter of 18.66 inches (474.16 mm). The thicker wall is required to effectively withstand higher levels of pressure.
These factors are justified as they follow industry standard calculation for SDR which is the ratio of the pipe’s outer diameter to wall thickness. A lower SDR means a higher pressure rating, which correlates with a thicker wall and ensures structural integrity on increased load conditions.
How do 24 HDPE pipe sizes compare to other pipe materials?
HDPE vs. steel pipe dimensions
While assessing dimensions of HDPE and steel pipes, certain technical aspects are pertinent, such as the diameter, wall thickness, pressure ratings, and material characteristics.
- Diameter: HDPE and steel pipes are produced with a variety of diameters. However, HDPE pipes are mostly manufactured under the SDR system, which guarantees a proportional relationship between the outer diameter of the pipe and the thickness of the wall. For example, a 24-inch HDPE SDR 11 would have a wall thickness of around 2.18 inches (55.37 mm). On the other hand, steel pipes have a nominal pipe size (NPS) system, which has schedule classifications such as Schedule 40 and Schedule 80 to specify wall thickness.
- Wall Thickness: HDPE pipe’s wall thickness is determined by the SDR which makes it easy to determine the pressure rating. In the case of steel pipes, the wall thickness increases with the schedule number. As an example, a 24-inch steel pipe Schedule 40 has a wall thickness of 0.688 inches (17.48 mm). and Schedule 80 increases this to 1.000 inches (25.4 mm). This demonstrates that HDPE pipes achieve higher degrees of flexibility while achieving comparable structural strength depending on application requirements.
- Pressure Ratings: Both the materials used and the SDR have a direct impact on the ability of an HDPE pipe to withstand pressure. For instance, an SDR 17 HDPE pipe will work under pressures of 125 psi, while SDR 11 supports up to 200 psi. The pressure ratings of steel pipes are usually a lot higher due to the strength of the material; for example, a Schedule 40 24-inch steel pipe usually has a psi rating between 285–and 300, depending on the steel grade.
The differences in material properties and manufacturing standards between HDPE and steel are reflected in the technical parameters. It is easier for HDPE to select appropriate wall thickness and SDR because of side dimensional reduction. In steel, it is common practice to schedule assignments allowing more extreme applications. Each material has distinct advantages depending on the application, with HDPE excelling in corrosion-prone installations and low to medium-pressure installations and steel in structurally rigid and high-pressure regions.
Differences between IPS and metric sizing systems
The most important difference between IPS (Iron Pipe Size) and the metric sizing system is in their measurement and range of use. The IPS system is imperial and therefore nominal pipe diameter is measured in inches while the metric system is in millimeters. This difference affects suitability as pipes and fittings made in one system are not directly used with those in the other system unless special adapters are used.
IPS pipes are mostly referred to by their Schedule (SCH) ratings which specify their wall thickness in terms of pressure rating. These include ratings like SCH 40 or SCH 80 where higher schedules usually denote thicker walls and greater pressure tolerances. Conversely, metric pipes use SDR (Standard Dimension Ratio) measures for example SDR 11 or SDR 17, which are the ratios of the pipe diameter to wall thickness. Thinner SDR values have better wall thickness and higher pressure performance.
To determine the best systems for various applications, factors like operating pressure, materials, and region-specific standards would be valuable. For example, in industrial processes with high pressure, it may be preferable to use IPS pipes with a high schedule rating. On the other hand, metric systems that have standardized SDR ratios might be best suited for precise installations in low to medium-pressure environments. This ensures that all the operational requirements are met while maintaining compatibility and performance efficiency.
What factors influence the selection of 24 HDPE pipe dimensions?
Pressure rating requirements for various applications
The selection of adequate pressure ratings for 24 HDPE pipes is crucial for the effectiveness and safety of pipeline systems. Pressure ratings are set mainly by the system’s operational pressure and the specified conditions under which the pipe will function. In the case of HDPE piping, the pressure classes are established from the material’s educational dimension ratio (SDR) and the resultant hydrostatic design stress.
- Standard Dimension Ratio (SDR): The ratio of the pipe’s outside diameter and its wall thickness. A lower SDR value (SDR 7 or SDR 9) means thicker walls, enabling the pipes to tolerate elevated pressures.
- Material Classification (PE4710): The resin employed such as PE4710 supports higher pressure capacities than PE3408, an older material, due to the exceptional strength and durability provided by the resin.
- Temperature Effects: As temperature increases, pressure ratings generally decrease. For HDPE pipes rated to operate at a maximum of 140°F, it is expected the capacity will be de-rated by up to 50% compared to 73°F.
- Safety Factor (SF): Nominal pressures from the industry like ASTM and ISO add SF into the calculation for long-term stress resistance and, as such, account for these in their standard operating conditions.
- Temporary Surge Allowances: Pipes could reach a temporary hydraulic shock; therefore, pressure surges must be considered during the sizing. Dynamic systems preferably utilize HDPE pipes designed to withstand surges. Allowable surge pressures are suggested to be lower than 1.5x the pipe’s pressure rating.
Through studying these technical aspects, the engineers should be able to select the relevant pipe dimension and schedule that meets the expected operating conditions, as well as ensures longevity and performance.
Flow capacity considerations based on pipe size
The flow capacity of a pipe is determined by its diameter, wall thickness, and the pipe’s material properties. In cases of larger hydraulic cross-sections, there is less restriction in flow rate, thus allowing for higher flow rates. Inversely, flow restriction within smaller cross-sections will result in increased velocity and friction losses. Pipe selection needs to consider requisite flow rate and hydraulic efficiency along with pressure limits, or the overall system may be compromised.
- Internal Diameter (ID): The ID of the pipe dictates the volume of fluid that can fit through. For HDPE pipes, the ID is subject to change with the chosen Standard Dimension Ratio (SDR).
- Flow Rate (Q): A measure of volumetric flow rate. Is most commonly expressed in GPM (gallons per minute) or L/s (liters per second). Flow rate optimally works with operational demands.
- Velocity (v): To reduce the amount of centrifugal forces along with the amount of erosion that may occur, the velocity for HDPE should remain below 5ft/s or 1.5m/s for water applications.
- Friction Loss (hf): The Darcy-Weisbach equation governs friction loss for hF. Long pipe runs at higher velocity withan increased roughness factor resulting in higher friction loss through the pipe system.
Considering the aforementioned, neglecting to consider the designed performance of the system while pipe selecting may result in inappropriate sizing of the pipe, thus costing efficiency and functionality.
How do I choose the right 24 HDPE pipe dimensions for my project?
Assessing fluid type and flow requirements
The first step I tackle when determining the ideal 24 HDPE pipe dimensions is examining the nature of these parameters like viscosity, temperature, and chemical compatibility with the HDPE material of the pipes. That way, I can ensure that the pipe will function without degradation and operational difficulties.
- Fluid Velocity (v): Water-based applications have to operate at a fluid velocity of under 5ft/s (1.5m/s) to mitigate erosion and pressure drop for optimal functionality.
- Friction Factor (f): My first step is to estimate the pressure drop using the pipe’s roughness, flow conditions, and, via the Darcy-Weisbach equation, the friction factor.
- Pipe Diameter (D): The inner diameter of the pipe has to support the flow rate while simultaneously having the velocity within the ideal range.
- Pressure Loss (ΔP): I calculate the pressure loss due to pipe length, velocity, and friction factor while keeping in mind that the system pressure needs to function within parameters.
By aligning these factors with project requirements, I can confidently determine if a 24-inch HDPE pipe meets the specific demands of the application.
Considering installation and service conditions
Installation Depth: The burial depth of the 24-inch HDPE pipe requires analysis in terms of traffic and soil loads. The pipe must be calculated so that it can withstand loads placed upon it.
- Temperature Range: The operational temperature range has a direct effect on the pipe material properties. The performance of HDPE should be checked against the service’s expected minimum and maximum operating temperatures while taking their thermal expansion or contraction into account which is possible by using the coefficient of linear thermal expansion.
- Jointing Method: As an example, butt fusion or electrofusion joints may be evaluated regarding the conditions of installation and system pressure. Those methods guarantee longevity and leak-free operations if proper procedures are taken according to ASTM regulations.
- Chemical Resistance: Verify the compatibility of HDPE with the fluids conveyed in the system, especially in industrial applications.
- External Loads: Check for the possible movements of the ground or operations through heavy machinery that may affect the pipe. Inspecting the movement and deflection limits of the pipe will allow ensuring all external forces are kept in mind. These measures employ the stiffness factor of the pipes and the deflection percentage.
These factors affect the pipe’s operation and the life of the pipe given its particular position and use.
What are common applications for 24 HDPE pipes?
Water distribution and sewage systems
Due to their strength, corrosion resistance, and flexibility, HDPE pipes are widely used for water distribution and sewerage systems. For potable water delivery, 24-inch HDPE pipes are approved for AWWA C906-compliant potable water lines and are suitable for Safe and Reliable Conveyance under different pressure conditions. Typically, water lines are rated for standard pressure classes of 100 psi, 125 psi, or 160 psi according to the application.
For these purposes, HDPE pipes also have superior chemical resistance to acidic and alkaline effluent for transporting wastewater. The smooth interior surface of HDPE pipes reduces friction losses (attributed to Hazen-Williams coefficients which usually range around 150), improves flow rate, and reduces blockage. These pipes are also built to withstand external pressure like soil infiltration and vehicular traffic which often characterize the stiffness of the soil with pipe SDR (Standard Dimension Ratio) such as SDR 26 or SDR 17^^.
Also, the flexibility of HDPE pipes enables them to stand ground movements or seismic movements without cracking which makes these pipes a robust solution for water distribution and sewage infrastructure.
Gas transportation networks
High-density polyethylene (HDPE) pipes are widely accepted across gas transportation networks due to their strength, durability, and low susceptibility to environmental and chemical factors. These pipes are constructed to safely transport natural gas and manufactured gases at different pressure ranges.
- Pressure Rating: HDPE pipes for gas tend to align with pressure classes such as PE 80 or PE 100, with operating pressure being the main design criterion. The common operating pressures seen are between 4 bar to 10 bar depending on the specific distribution network.
- Temperature Resistance: HDPE pipes can function in a temperature range of -40 to 60 degrees Celsius and 60 to 60 degrees Celsius which means they can withstand extreme climate without having any structural damage.
- Flexibility and Impact Resistance: With high elongation at break (usually above 600%), HDPE pipes show excellent flexibility and can accommodate thermal expansion, dynamic soil conditions, and seismic activities without breaking.
- Jointing Systems: Fusion welding (butt fusion and electrofusion) makes leakproof jointing achievable and is critical in gas transportation to avoid fugitive emissions from the system.
- Standards Compliance: Compliance with ASTM F2619/F2619M or ISO 4437-2 is a prerequisite for the use of HDPE pipes in gas installations as it governs material characteristics, pipe size, and operating conditions.
Due to the HDPE pipe’s extremely low permeability in combination with being corrosion resistant, the life cycle value for the gas infrastructure is achieved because maintenance is practically nonexistent. On top of that, with the cost benefits, HDPE proves to be the best option for gas distribution systems and even gas transmission systems.
Reference sources
Frequently Asked Questions (FAQs)
Q: What is HDPE pipe and what are its common applications today?
A: HDPE (High-Density Polyethylene) pipe is a versatile product used in various industries. Today, it’s commonly used for water mains, gas distribution, sewage systems, and industrial applications due to its durability, flexibility, and corrosion resistance.
Q: How can I get access to a comprehensive HDPE pipe size chart?
A: You can get a detailed HDPE pipe size chart from pipe manufacturers, industry associations, or online resources. These charts typically include information on nominal pipe size, actual outside diameter, and minimum wall thickness for different pressure ratings.
Q: What are the standard sizes available for HDPE pipes?
A: HDPE pipes are available in a wide range of sizes, typically from 1/2 inch to 63 inches in diameter. Common sizes include 2, 4, 6, 8, 12, 16, 20, 24, 32, 40, and 50 inches. The actual dimensions may vary slightly depending on the manufacturer and pressure rating.
Q: How do I determine the correct HDPE pipe size for my project?
A: To determine the correct HDPE pipe size, consider factors such as flow rate, pressure requirements, and local regulations. Consult with a professional engineer or use hydraulic calculation software to avoid confusion and ensure the proper size is selected for your specific application.
Q: What is the difference between nominal size and actual size in HDPE pipes?
A: Nominal size is an approximate designation used for reference, while actual size refers to the precise measured dimensions of the pipe. For example, a 2-inch nominal HDPE pipe may have an actual outside diameter of 2.375 inches. Always refer to the HDPE pipe size chart for accurate dimensions.
Q: How does wall thickness affect HDPE pipe performance?
A: Wall thickness is crucial for determining the pipe’s pressure rating and durability. Pipes with a greater minimum wall thickness can withstand higher pressures and are more resistant to external damage. The Standard Dimension Ratio (SDR) is used to express the relationship between pipe diameter and wall thickness.
Q: How do temperature changes affect HDPE pipe dimensions?
A: HDPE pipes expand and contract with temperature changes. On average, HDPE pipes expand about 1 inch per 100 feet for every 10°F increase in temperature. This thermal expansion should be accounted for in design and installation to prevent stress on joints and fittings.
