Pegasus Pressfit M-Profile Pipe Fittings — Push-Fit 15mm, 22mm and 28mm for UK Plumbers

Push-fit pipe fittings have become a staple of UK plumbing for good reason. They connect quickly, need no flame or specialist tools, and produce reliable joints when installed correctly. The Embrass Peerless Pegasus Pressfit M-Profile range covers every common fitting type in 15mm, 22mm and 28mm, making it a versatile choice for residential and light commercial work.

This guide covers the fitting types available, where each size applies, and how the M-Profile connection compares to compression and end-feed alternatives.

What Is the M-Profile Push-Fit System?

M-Profile (also called metric push-fit) fittings work by gripping pipe with an internal collet ring. When you push copper or plastic pipe into the fitting body, the collet locks onto the pipe surface. A rubber O-ring provides the watertight seal. To release the joint, you depress the collet release and withdraw the pipe.

Pegasus Pressfit M-Profile fittings are designed for use with:

• Copper pipe (to BS EN 1057)
• CPVC pipe
• Polybutylene (PB) pipe
• PEX pipe (with insert support liners where required)

They are rated for hot and cold water supply systems and are suitable for central heating circuits where the system operates within normal residential temperature and pressure parameters.

Fitting Types in the Pegasus Pressfit Range

The Pegasus Pressfit M-Profile range covers all the standard fitting forms a plumber needs on a typical installation:

Couplers (Straight Connectors)

The straight coupler joins two lengths of pipe in the same diameter. Available in 15mm, 22mm and 28mm equal bore, plus reducing versions that step down between sizes — for example 22mm x 15mm or 28mm x 22mm — without needing a separate reducer bush.

Slip Couplers

A slip coupler has no internal stop, allowing it to be slid fully onto one pipe and then drawn back to bridge a gap. They are used for repair joints where you cannot slide a standard coupler onto a fixed pipe run. Available in 15mm, 22mm and 28mm.

Elbows

The 90-degree elbow changes pipe direction without bending. The M-Profile elbow is available as a plain 90-degree fitting in all three bore sizes, plus:

• Street elbow — one push-fit socket, one male spigot, for tight-space connections
• Wall plate elbow — with a backplate for fixing to a wall, typically used for connecting washing machine or dishwasher inlets
• Female elbow — push-fit socket one end, BSP female thread the other, for connections to screwed fittings

Tees

Equal tees in 15mm, 22mm and 28mm allow branch connections off a main pipe run. Reducing tees are available where the branch or main bore differs from the run — for example 22mm x 15mm x 22mm for taking a 15mm branch off a 22mm mains run, or 28mm x 22mm x 28mm for heating primary circuits.

Stopends

A push-fit stopend caps a pipe end and can be removed for future extension. Available in 15mm and 22mm, they are useful for temporary isolation during first fix before final commissioning.

Part Crossover

The part crossover (also called a bent pipe connector or crossover fitting) allows two parallel pipes to cross without connecting. Available in 15mm and 22mm, it is used in congested pipework layouts where pipe runs must avoid each other in the same plane.

Male and Female BSP Connectors

BSP transition fittings are available in multiple configurations:

• Coupler Male — push-fit socket to male BSP thread
• Coupler Female — push-fit socket to female BSP thread
• Wall Plate Elbow — 90-degree turn with BSP thread for tap tails, valve connections or appliance inlets

These are available in 15mm x 1/2", 15mm x 3/4", 22mm x 1/2", 22mm x 3/4", 22mm x 1" and 28mm x 3/4" combinations.

Size Guide: 15mm, 22mm and 28mm Applications

15mm Push-Fit Fittings

The most-used size in domestic plumbing. 15mm pipe runs to individual outlets: taps, radiators, toilet cisterns, shower valves and washing machine connections. If you are routing pipe from a 22mm distribution point down to a single tap or valve, the branch work will almost always be 15mm. The Pegasus Pressfit range covers the full fitting suite in 15mm, including the wall plate elbow for appliance connections.

22mm Push-Fit Fittings

Used for distribution runs, boiler primary circuits and cold mains where higher flow is required. A typical installation uses 22mm for the main hot and cold distribution from the cylinder or mains, dropping to 15mm at each outlet. Reducing couplers and tees in 22mm x 15mm simplify this transition.

28mm Push-Fit Fittings

Found on boiler flow and return connections, mains cold water supplies in larger properties, and primary circuits on system and heat-only boilers where pipe sizing specifies larger bore. The 28mm Pegasus Pressfit range includes reducing tees and couplers for connecting back to 22mm or 15mm secondary pipe runs.

Push-Fit vs Compression vs End-Feed: Which to Use?

Push-fit is the go-to choice for first and second fix work where speed matters, for repairs in occupied properties where a torch is undesirable, and for flexible pipe connections. Compression remains the tradesperson's preference for concealed stopvalves and for connections that may need future adjustment. Solder-ring and end-feed fittings suit new copper pipe runs where the joint will be buried and permanence is a priority.

Installation Tips for Pegasus Pressfit M-Profile Fittings

1. Cut pipe square. A clean, square pipe end seats correctly against the O-ring. Use a pipe slice rather than a hacksaw where possible; deburr the cut end before insertion.
2. Mark the insertion depth. Mark the pipe to the depth indicated on the fitting body before pushing home. This confirms the pipe has fully engaged the collet.
3. Push firmly to the stop. Apply even, steady pressure until the pipe reaches the internal stop. A partial insertion will not compress the O-ring fully and will leak under pressure.
4. Tug-test every joint. After insertion, pull the pipe to check the collet has engaged. The fitting should grip firmly.
5. Use pipe inserts for plastic pipe. When fitting to PEX or polybutylene, insert the appropriate pipe liner into the pipe end first to prevent the collet from deforming the pipe wall.
6. Pressure test before closing in. Always carry out a system pressure test before covering or burying any push-fit joints. Test to 1.5 times working pressure for at least one hour.

Featured Products

15mm Pegasus Pressfit M-Profile Coupler

Straight coupler for joining 15mm copper or plastic pipe. No tools required. Internal collet and O-ring seal.

£1.10

Buy Now

15mm Pegasus Pressfit M-Profile Elbow

90-degree elbow for changing direction on 15mm pipe runs. Quick push-fit connection, demountable.

£1.48

Buy Now

22mm Pegasus Pressfit M-Profile Tee

Equal tee for branching off 22mm distribution runs. Suits hot and cold water supply and central heating circuits.

£4.11

Buy Now

22mm x 15mm Pegasus Pressfit Reducing Coupler

Steps down from 22mm distribution main to 15mm outlet pipe. Eliminates need for separate reducer bush.

£2.41

Buy Now

View the full Embrass Peerless Pegasus Pressfit range at APM Electricals.

Frequently Asked Questions

Can Pegasus Pressfit M-Profile fittings be used in concealed pipework?

Always check the manufacturer's current data sheet before concealing push-fit joints. Many push-fit fittings are approved for use in floor and wall voids provided the system is tested before closing in and the pipe run can be accessed for inspection. Where regulations or insurance require fully soldered concealed joints, use end-feed or solder ring alternatives.

What sizes does the Pegasus Pressfit M-Profile range cover?

The range covers 15mm, 22mm and 28mm bore sizes, with a comprehensive selection of reducers and BSP transition fittings across all three sizes.

How do I release a Pegasus Pressfit fitting?

Depress the collet ring (the plastic ring at the mouth of the fitting) evenly while pulling the pipe. A collet release tool makes this easier in tight spaces. Drain the pipe before attempting removal and take care not to damage the O-ring if the fitting is to be reused.

Are these fittings compatible with plastic pipe systems such as Speedfit?

The Pegasus Pressfit M-Profile collet dimensions are designed for metric copper and compatible plastic pipes. Always verify compatibility with the specific plastic pipe system you are using. Use the correct pipe liner inserts for plastic pipe types where required.

Is the Pegasus Pressfit range suitable for central heating?

Yes, within the temperature and pressure parameters of residential central heating systems. Check the manufacturer's maximum operating temperature and pressure ratings and ensure your system does not exceed them.

APM Electricals
Unit 3, The Old Vinyl Factory, Blyth Road, Hayes, Middlesex, UB3 1DD
Phone: 020 8574 0077

Browse push-fit fittings: Plumbing Fittings at APM Electricals