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Got Questions? We've Got Answers!

Welcome to our FAQ’s page where you will find answers to the most commonly asked questions.

  • What standard does Union Global supply their pipe?

    Union Global generally supplies pipe in accordance with ISO 4427 and can also supply pipe to suit customer requirements and other standards.

  • What are some common applications for HDPE Pipe?

    Our pipe has many uses. Irrigation, sewerage, drinking water lines and more. See page 8 of our catalog for more examples of applications.

  • Can Union Global prefabricate sections per my specifications?

    YES. Send us a drawing and we will provide an estimate.

  • Does Union Global have a minimum order quantity for pipe?

    Yes, however we maintain stock of most sizes and can supply small quantities in most instances. Contact our sales department for more information.

  • What are typical lead times?

    Lead times will vary depending on the quantity and size of pipe required. Contact our sales department for more information.

  • Can PE pipe be installed without digging a trench?

    Yes. PE pipe can be installed with pipe bursting, slip lining, or horizontal directional drilling (HOD) techniques, all of which are trenchless.

  • How does the overall cost of PE compare in price with other materials?

    Underground water pipes are a major long term (50-100years) investment. In addition to comparing the initial purchase price, the long term maintenance costs and overall life-cycle costs should be carefully evaluated. Compared to PVC and ductile iron, PE has the lowest life-cycle costs due to lower installation costs, lower repair rates, less water loss and lower energy costs.

  • Are there certain soil requirements for PE pipe?

    No. PE pipe is known for its flexibility, toughness and chemical resistance. PE pipe can withstand great pressure changes due to its outstanding ductility and toughness. These performance characteristics make PE pipe an excellent choice for dynamic soils and earthquake prone areas that require a strong, long-lasting and corrosion-resistant pipe that is also flexible enough to be installed and assembled in harsh and challenging environments.

  • What can HDPE pipe be used to carry?

    PE pipe can be used to transport potable water, waste water, chemicals and compressed gas.

  • How many wall thicknesses are available?

    Generally pipes are produced in accordance ISO  4427 (see page 65 of our catalog for more details).  In addition custom thickness can be supplied such as thin wall sleeve pipe and duct pipe.

  • What pipe lengths are available?

    Smaller diameter pipes can be supplied in 50m to 100m rolls. Larger diameter pipes can be supplied in 6m and 12m lengths. We can also supply customs lengths based on your requirements. Please contact our sales staff for more information.

  • What are the advantages of PE pipes?

    The advantages of HDPE pipes are

    1. Leak proof techniques
    2. Versatile
    3. Flexible
    4. Cost effective
    5. Durable
    6. Lightweight
    7. Resistance to corrosion and chemicals
    8. Superior flow characteristics
    9. Safe for Water Distribution
  • Where can dimensional information such as outside diameter, wall thickness and inside diameter of the various sizes of HDPE pipe be found?

    In our catalog or click here

  • How does the use of HDPE pipe save money for a utility?

    HDPE pipe provides the lowest life cycle cost when compared to other systems due to significantly reduced or no leakage, increased billable dollars, water conservation, fewer new water-treatment plants, reduced maintenance crews, reduced seasonal water-main breaks, and no loss in flow capacity over the long term.

  • What do the terms DR and SDR mean?

    DR stands for Dimension Ratio which is the average outside diameter (note: DR is also used for PVC pipe) divided by the minimum wall thickness. A Standard Dimension Ratio (SDR) is a specific DR based on ISO preferred number series The use of SDR’s enables manufacturers to produce pipe to a set of standardized DR’s. SDR’s include 9, 11, 13.5, 17, 21, 26, and 32.5. All SDR’s are DR’s, but not all DR’s are SDR’s.

  • Is thermal expansion and contraction of HDPE pipe a problem?

    No. All pipes expand and contract with change in temperature. The key is management of the resultant thermal strain. As with all materials, expansion and contraction must be taken into consideration when designing a HDPE piping system. Buried pipelines usually do not move due to soil friction. However, thermal effects must be considered for above grade applications.

  • After HDPE has been buried and allowed to relax, will the pipe continue to expand and contract a great amount with temperature variations?

    No. When HDPE pipe is buried, the temperature of the system becomes much more stable than an above ground pipeline and therefore will exhibit far less dimensional change. In most systems, buried HDPE pipe does not move after it is buried.

  • Do I have to be concerned with the long-term effects of creep?

    All plastic materials, including HDPE and PVC, are subject to creep. Proper design, such as using the long-term modulus of the material where appropriate, accounts for creep effects.

  • Is there a flow loss in HDPE pipe due to the inner bead resulting from the butt fusion process?

    The fusion bead has very little effect on the flow as it is basically rounded and protrudes very little on the inside surface of the pipe Secondly, the Hazen-Williams C-factor of 150 takes into account the inner bead. Field tests confirm that a 150 C- factor used in the Hazen- Williams equation properly calculates actual flow and that the bead is of no hydraulic significance for either pressure or flow. The Hazen-Williams Friction Factor, C, for PE pipe was determined in a hydraulics laboratory using heat fusion joined lengths of pipe with the inner bead present.

  • Will sunlight adversely affect HDPE pipe?

    Carbon black, utilized in most all HDPE pipe is the most effective ultraviolet stabilizer and therefore, black is the recommended pipe color for exposed long term service or storage. Pipe of this color will provide decades of outdoor use similar to that of black power-line cable jacketing. HDPE pipe produced in non-black colors may also be supplied for outdoor exposure (storage and use) but its life expectancy is much less and is usually specified for a particular time period. Questions on this topic should be referred to the pipe manufacturer.

  • What is the life expectancy of HDPE pipe in water applications?

    Many installations of HDPE pipe in water applications are already reaching 50 years of successful service. The polyethylene pipe industry estimates a service life for HDPE pipe to conservatively be 50-100 years but this will vary based on pipe service conditions. This relates to savings in replacement costs for generations to come.

  • Will HDPE pipe float in water?

    Yes, HDPE pipe, due to its density being slightly less than water, will float even when full of water.

  • How does the impact strength of HDPE compare with other pipes?

    HDPE is a ductile material and has exceptional impact strength. HDPE’s superior impact strength provides a piping system that is near impervious to impact damage and to damage from improper tapping. In the real world, engineers understand that pipes must be tough and resist impact and handling damage. HDPE pipes are field tested and proven to be impact tough.

  • How are HDPE pipe segments joined and connected?

    HDPE pipe is easily and dependably joined using the standardized butt-fusion procedure. In this process matching ends of the pipes to be joined are aligned and heated with standard tools until the surfaces have become molten. When engaged under moderate pressure, the melt faces flow together forming a monolithic, homogeneous joint that, as the material cools, yields joints that are as strong as or stronger than the pipe itself.

    There are several other well established heat fusion procedures used to join HDPE pipe such as electro fusion, which is exceptionally well suited for the assembly of pipe to fittings, or for making tie-ins or repairs, and saddle fusion which is used for the attachment of service fittings to HDPE mains. Apart from the heat fusion process of joining HDPE pipe, it can also be joined successfully with a variety of mechanical style fittings.

  • Can butterfly valves be used with flanged HDPE pipe?

    Yes. In some cases, depending on the butterfly valve dimensions, butterfly valve flange adapters, or standard flange adapters with tapered ID spacers are required in order for the valve to open & close freely.

  • What brand of HDPE pipe does Union Global supply?

    Union Global is the sole distributor of products manufactured by Hydro Dynamic Pipe Engineering.

  • What is the availability of HDPE pipes and fittings?

    Contact our sales staff for the availability of your specific requirements.

  • What approvals does Union Global have?

    Union Global currently has the following approvals and has supplied to many high profile projects and clients

    1. FEWA
    2. Armed Forces
    3. WRAS
    4. Ministry of Public Works

    Be sure to check with our sales staff as we are constantly pursuing registration with many other bodies.

  • How many trailers will I need to transport the pipes?

    Refer to page 70 in the Union Global catalog for an estimate on how many pipes will fit on a standard 40ft trailer.

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