MDPE Pipe Fittings

We specialise in providing a wide range of MDPE fittings suitable for both above and below ground applications. Our selection caters to all your needs, ranging from 20mm to 125mm fittings, ensuring compatibility with both blue and black MDPE water pipes. Whether you're looking to install a robust system for potable water or need a reliable solution for your irrigation requirements, our MDPE water pipe fittings are perfect for the job.


Designed for ease of use, our MDPE compression fittings are straightforward to install and require only a strap wrench to ensure the fitting nuts are sufficiently tightened, promoting a secure and leak-free connection. Ideal for a variety of temperature conditions, these fittings are rated for pressures up to 16 bar and conform to ISO 17885:2021 standards, offering both durability and safety with a safety factor of 3. From domestic water systems to agricultural setups, and even transitions like MDPE to copper, our fittings provide the reliability and performance you need for any project.

Technical Information For MDPE Fittings

  • Pressure Rating: 16 bar
  • Safety Factor: 3
  • Operating Temperature: 20°C @ 16 bar
  • Standards: ISO 17885:2021
  • Compliance: UK REG4 Compliant
  • Sizes: 20mm-125mm
  • Suitability: Cold and ambient temperature water

Our MDPE fittings are approved for above and below ground use, and can be used for potable (drinking) water applications with black and blue MDPE pipe.

The majority of our MDPE fittings have a pressure rating of 16 bar, however, there are a few exceptions which are as follows:

  • Female adaptor 75mm x 2" to 110mm x 4" - 10 bar
  • 90° female threaded tee from 75mm x 2" to 110mm x 4" - 10 bar
  • 90° female threaded elbow from 75mm x 2" to 110mm x 4" - 10 bar

How To Install MDPE Fittings

  1. Prepare the Pipe:
    • Cutting: Use a pipe cutter to ensure a clean, square cut on the MDPE pipe. A straight cut is crucial for a proper fit.
    • Cleaning: Clean the end of the pipe thoroughly. Remove any dirt, grease, or burrs using a pipe scraper or fine sandpaper. This step is important to prevent any debris from compromising the seal.
  2. Prepare the Fitting:
    • Disassemble the compression fitting. Typically, this includes loosening and removing the nut, then taking off the thrust ring (also known as a grip ring), and the O-ring.
    • Check all parts to ensure they are clean and undamaged.
  3. Mark the Insertion Depth:
    • Measure the depth of the fitting socket and mark this distance on the outside of the pipe with a marker. This indicates how far the pipe needs to be inserted into the fitting for a proper seal.
  4. Assemble the Fitting on the Pipe:
    • Slide the nut onto the pipe, followed by the thrust ring, and then the O-ring over the pipe end. Ensure they are in the correct order and facing the right direction.
    • Push the pipe into the fitting body up to the marked line. Ensure it is inserted straight to avoid damaging the O-ring.
  5. Tighten the Fitting:
    • Hand-tighten the nut onto the fitting body to avoid cross-threading.
    • Once hand-tight, use a strap wrench to tighten further. Typically, tightening the nut between one-half and three-quarters of a turn past hand tight is sufficient. Over-tightening can damage the fitting and pipe, so proceed with caution.
  6. Inspect the Installation:
    • After installation, visually check the assembly to ensure there are no gaps and that the nut is secure. A proper installation should feel solid and show no signs of distortion or stress on the pipe.
  7. Test for Leaks:
    • If the system allows, perform a pressure test to ensure there are no leaks at the connection. This is done by applying water pressure to the system and observing for any seepage around the fitting.

Additional Tips:

  • Temperature Consideration: If you’re working in very cold or hot conditions, consider the effects of temperature on MDPE pipe flexibility and fitting expansion or contraction.
  • Use of Tools: While tightening, ensure the tools used are appropriate for the size of the fittings to avoid slipping or damaging the components.
  • Regular Checks: For systems under regular use, periodically check the integrity of the fittings as part of routine maintenance.
  • Following these steps will help ensure a reliable and durable connection using MDPE fittings, ideal for various applications from domestic water supply to irrigation systems.

How To Remove MDPE Fittings

Removing MDPE (Medium Density Polyethylene) fittings, especially compression fittings, can be done without damaging the pipe or the fitting if done carefully. This allows the fittings to be reused or replaced as necessary. Here’s how to properly remove MDPE compression fittings:

  1. Relieve Pressure:
    • Ensure that any pressure in the pipe is fully relieved before starting the removal process. This might involve turning off the water supply and opening a tap or valve to release water and pressure.
  2. Access the Fitting:
    • Clear any soil, debris, or insulation from around the fitting to ensure you have good access and visibility.
  3. Loosen the Nut:
    • Use an adjustable spanner or a strap wrench to loosen the compression nut that holds the fitting in place. In most cases, turning the nut counter-clockwise will loosen it.
  4. Remove the Nut and Other Components:
    • Once the nut is loose, slide it along the pipe, followed by the grip ring (thrust ring), and the O-ring. Keep these components in order, and inspect them for damage. If they are worn out or damaged, the fitting should be replaced.
  5. Separate the Pipe from the Fitting:
    • Gently pull the pipe out of the fitting body. If the pipe is stuck, it might be necessary to wiggle it slightly to free it. Be cautious to avoid damaging the end of the pipe or the inner surface of the fitting.
  6. Inspect and Clean:
    • Inspect the end of the pipe for any damage. If the pipe is damaged, it might be necessary to cut off the damaged section using a pipe cutter. Ensure the remaining pipe is clean and free of debris or damage before reusing.
    • Clean the fitting thoroughly if you plan to reuse it. Check the interior components and body for any signs of wear or damage.
  7. Reassembly or Capping:
    • If you're not immediately replacing the fitting, cap the end of the pipe or close the system appropriately to prevent contamination or leakage.

Tips for Successful Removal:

  • Gentleness: Apply gentle pressure when pulling the pipe from the fitting. Forceful pulling can damage the pipe or the fitting.
  • Tool Use: Ensure that the tools used do not damage the components, especially the nuts and O-rings, which are critical for ensuring a leak-proof reinstallation.

By following these steps, you can safely remove MDPE fittings without causing damage, allowing for adjustments, repairs, or system modifications with minimal disruption and cost.

Threaded MDPE Fittings

Male Threaded Fittings – Tapered Threads:

  • Design: Male threaded MDPE fittings use a tapered thread, which means the diameter of the threads decreases gradually from one end to the other. This design is based on standards such as NPT (National Pipe Taper) or BSP Taper, which are widely used in plumbing and fluid systems.
  • Purpose: The taper in the threads allows them to fit more snugly as they are screwed into a female fitting. As the male fitting is tightened, the threads compress and deform slightly, filling gaps and creating a mechanically tight seal.
  • Advantages: The taper provides a reliable sealing action that increases with the tightening of the fitting, helping to prevent leaks under a range of pressures and conditions.

Female Threaded Fittings – Parallel Threads:

  • Design: Female threaded MDPE fittings feature parallel threads, where the diameter of the threads remains consistent along their length. This style conforms to standards such as BSP Parallel or NPS (National Pipe Straight).
  • Purpose: Parallel threads in female fittings provide a consistent and stable structure for the male taper threads to screw into, allowing for uniform contact along the length of the thread interaction.
  • Advantages: This design helps maintain the alignment and integrity of the connection, providing a stable base that supports the sealing effect of the male taper.

Use of PTFE Tape:

  • Application: PTFE tape, commonly known as thread seal tape or plumber's tape, is used to wrap the threads of the male fitting before it is screwed into the female fitting. The tape is applied in a direction consistent with the thread spiral, usually wrapped two to three times.
  • Function: When the male tapered thread with PTFE tape is inserted into the female parallel thread, the tape fills any microscopic gaps between the threads, enhancing the seal. The tape acts as a lubricant, allowing for deeper seating of the male threads as they are tightened, and it deforms into the shape of the threads, creating a seal that is tight and more resistant to leaks.
  • Benefits: PTFE tape is especially effective in preventing the escape of gases and liquids in pressurised systems. It compensates for any minor imperfections in the thread form or machining, ensuring a durable seal.

The combination of tapered male threads and parallel female threads in MDPE fittings, along with the use of PTFE tape, creates a highly effective sealing system. This system leverages the mechanical advantage of the taper design, which increases contact pressure during fitting engagement, along with the chemical resistance and sealing capabilities of PTFE tape, to ensure a secure, leak-proof connection suitable for a variety of plumbing and industrial applications. This thoughtful design maximises both the mechanical and material properties of the fittings to provide reliable performance in demanding environments.

What Are Universal Transition Fittings?

Universal Transition Fittings, commonly referred to as UTC (Universal Transition Coupling), represent a breakthrough in piping technology, offering unprecedented flexibility and compatibility across a wide range of pipe materials. These fittings are designed to simplify plumbing connections, reduce the need for multiple specialised fittings, and provide a robust solution in diverse installation environments.

Key Features of Universal Transition Fittings:

  • Broad Compatibility: Universal Transition Couplings are engineered to connect seamlessly with multiple types of pipe materials without the need for modification. This includes, but is not limited to, MDPE, PVC, ABS, copper, stainless steel, galvanised iron, and lead. Such versatility makes them ideal for retrofitting and repairs in complex systems where different pipe materials are present.
  • Size Range: These couplings are available in a variety of sizes ranging from 15-21mm x 20mm to 59-61mm x 63mm, catering to a broad spectrum of piping dimensions. Each size fitting is designed to cover a range of pipe diameters, providing a universal solution that simplifies the installation process and inventory requirements
  • Pre-Assembled for Convenience: Universal couplings come pre-assembled and are ready to use, which speeds up the installation process. This feature is particularly beneficial in situations where quick repairs or modifications are needed.
  • Advanced Gripping System: The UTC ends of these couplings contain hard stainless steel gripping teeth that offer superior end-load resistance. This gripping mechanism ensures that once a pipe is inserted and the nut tightened, the connection will be secure and resistant to pulling forces, enhancing the reliability of the joint.
  • Easy Installation and Disassembly: Universal Transition Fittings are designed for fast and easy installation, allowing for simple insertion and tightening of the nut to achieve a leak-proof seal. They are also easy to disassemble, providing flexibility in maintenance and adjustments.
  • Sealing Performance: These fittings include a pipe liner and are known for their outstanding sealing performance. They are designed to maintain integrity under various conditions with a pressure rating of up to 12.5 bar at 20°C.
  • Range of Products: Philmac UTC is available in several configurations, including straight and reducing couplers, elbows, and male adaptors. These are available in both transition (PE to UTC) and double-ended versions (UTC to UTC), further enhancing their adaptability.
  • Certifications: The fittings are WRAS approved for use with drinking water, ensuring they meet rigorous health and safety standards.

How To Install A Wall Plate Elbow

Installing a wall plate elbow, often used for securing outdoor taps to a wall and connecting them to the water supply, involves a straightforward process. This type of fitting typically combines a wall mounting plate with an elbow that has a threaded outlet for the tap and an inlet for connecting to the water supply pipe. Here’s a step-by-step guide on how to install a wall plate elbow:


Steps for Installation:

  1. Prepare the Location:
    • Decide where you want to install the tap and wall plate elbow. It should be easily accessible and close to the existing water supply line.
    • Use a spirit level to mark the position on the wall where the wall plate elbow will be mounted. Ensure it is level to avoid uneven stress on the piping and connections.
  2. Drill and Secure the Wall Plate:
    • Once the position is marked, drill holes for the wall plugs. The number and size of the holes depend on the design of the wall plate elbow and the type of wall (e.g., brick, concrete, or wood).
    • Insert wall plugs into the drilled holes.
    • Align the wall plate elbow over the holes and secure it with screws through the mounting holes into the wall plugs. Tighten securely but take care not to over-tighten and damage the wall or the plate.
  3. Prepare the Pipe Connection:
    • Measure and cut the supply pipe that will connect to the elbow’s inlet. Ensure the pipe is cut cleanly and deburred.
    • If using copper or MDPE pipe, ensure you have the correct fittings ready to securely connect the pipe to the inlet of the wall plate elbow.
  4. Connect the Supply Pipe:
    • If using flexible piping like MDPE, it might require a compression fitting or push-fit connection depending on the type of wall plate elbow.
    • Ensure all connections are tight and leak-free. Use PTFE tape on threaded connections to ensure a watertight seal.
  5. Install the Tap:
    • Wrap PTFE tape around the tap’s threads to ensure a good seal.
    • Screw the tap into the threaded outlet on the elbow. Use an adjustable wrench to tighten it securely but be careful not to over-tighten, which could damage the tap or threads.
  6. Check for Leaks:
    • Turn on the water supply to check for any leaks at the connections. Tighten any fittings if necessary to stop leaks.
  7. Final Setup:
    • Once everything is connected and checked for leaks, ensure that the area around the installation is clean and that all tools and materials are removed.

If you require any further information, our excellent customer service team is here to help so please call us on 01794 835835.