Aquaflow 110mm Soil Pipe Fittings — Pushfit System Guide for UK Plumbers

Whether you're running a new soil stack, extending a bathroom, or replacing a failing pipe section, getting your 110mm soil pipe fittings right matters. Aquaflow's pushfit system is one of the most widely used in UK domestic plumbing — no solvent cement, no drying time, and fully demountable if you need to adjust the run later.

This guide covers the key Aquaflow 110mm pushfit fittings, when to use each type, and how to get a leak-free result first time.

Why Choose Pushfit Over Solvent Weld?

Soil pipe work is generally done in one of two ways: solvent weld (glued joints that are permanent) or pushfit (rubber-ring joints that are removable). Each has its place.

Pushfit advantages:

• No drying time — joints can be tested immediately
• Allows slight angular deflection (useful for ground movement or misaligned stacks)
• Demountable — if you make a mistake or need to alter the run, the joint can be pulled apart
• Suitable for internal above-ground drainage (BS EN 1329-1)

Solvent weld advantages:

• Permanent, rigid joint — better where vibration or movement is a concern
• Typically cheaper per fitting
• Preferred where access to fittings is restricted after installation

For most domestic soil stack work — running from WC, bath, and basin outlets up through the floor and out the roof — pushfit is the practical choice. Aquaflow's 110mm pushfit range is fully compatible with standard 110mm soil pipe from any manufacturer.

Key Aquaflow 110mm Pushfit Fittings

Socket Plug

The 110mm pushfit socket plug is used to blank off an open socket end — for example, capping an unused branch port, protecting a pipe during installation, or temporarily sealing a stack while work is in progress. The grey variant is particularly popular for compatibility with grey PVC pipe and discreet appearance in visible runs.

Straight Coupling

Used to join two lengths of 110mm soil pipe end-to-end. The double-socket pushfit coupling accepts spigot ends from both sides and seals via twin rubber rings. Essential when you're extending a run or replacing a damaged section. Check that pipe ends are cleanly cut and deburred before pushing home.

92.5° Swept Bend (Double Socket)

The swept 92.5° bend is the standard fitting for changing direction in a soil stack — typically used at the base of a vertical stack where it transitions to a near-horizontal underground run. The double-socket version accepts pushfit pipe from both ends. The swept (long-radius) profile reduces the risk of blockages compared to tight-radius alternatives.

Note: for the actual right-angle turn at the foot of a stack, use the 92.5° swept bend rather than a tight 90° knuckle bend — the swept profile is better for flow.

Adjustable Bend (0–45°)

When your stack hits an obstacle — a joist, a lintel, a beam — the adjustable bend solves the problem without cutting a custom angle. It can be set anywhere from 0° (straight) to 45°, and the pushfit ends mean no adhesive is needed. Available in 0–45° and 0–90° versions depending on the deflection required.

Installation Tips

Cutting and Preparing Pipe

Use a fine-tooth saw or pipe cutter for a clean, square cut. Deburr the outside edge of the spigot with a file or deburring tool — a rough edge will cut into the rubber seal and cause a slow leak. Chamfer the leading edge at approximately 15° to help the spigot enter the socket without rolling the seal.

Lubrication

Apply a thin smear of petroleum jelly or proprietary pipe lubricant to the rubber ring and the chamfered spigot end. Do not use washing-up liquid — it dries out and can cause the seal to squeak or leak. Push the spigot in firmly and squarely to the socket stop.

Expansion Gap

Soil pipe expands and contracts with temperature. When inserting a spigot into a pushfit socket, withdraw it by 10mm from the stop to leave an expansion gap. Mark the insertion depth with a pencil before pushing home, then pull back 10mm. Failure to leave this gap can cause buckling in warm weather.

Pipe Clips and Support

Support horizontal runs at no more than 900mm centres for 110mm pipe. Vertical stacks should be clipped at every floor level. Use adjustable boss clips or ring clips — avoid over-tightening, which can distort the pipe.

Compatibility

Aquaflow 110mm pushfit fittings are manufactured to BS EN 1329-1 and are compatible with standard 110mm (nominal 4") soil pipe from all major UK manufacturers including Floplast, Polypipe, and Brett Martin. The rubber seals are EPDM — suitable for above-ground internal drainage carrying normal domestic waste (grey water, WC waste). Not suitable for chemical waste or industrial effluent without checking individual product specifications.

Frequently Asked Questions

Can I mix Aquaflow pushfit fittings with solvent weld pipe?

Yes — the socket accepts the spigot (plain end) of any standard 110mm pipe, whether it's intended for pushfit or solvent weld. The fit is determined by the pipe's outside diameter, which is standardised. Solvent weld pipe has a slightly larger-wall thickness on some products, so check for a smooth insertion before committing.

Can pushfit 110mm fittings be used underground?

Aquaflow's pushfit range is rated for above-ground use only (BS EN 1329). For underground drainage, use the Aquaflow 110mm underground (terracotta or ring-seal) range, which is manufactured to BS EN 1401.

My socket plug won't stay seated — what's wrong?

Check that the spigot end (the plug's tail) is fully inserted to the socket stop. If the plug keeps backing out, the pipe end may be slightly undersized — try lubricating the seal and pushing in firmly. For a positive retention, use a solvent weld socket plug instead.

How do I know if a pushfit joint is watertight?

Test by filling the stack above the connection and watching for drips. For a pressure test, cap all outlets and charge the system to 50mm water gauge for 15 minutes. Any weeping joints should be pulled apart, the seal checked for damage or dislodgement, and re-made.

Aquaflow 110mm Pushfit Waste Socket Plug — Grey

Blanks off open 110mm pushfit socket ends. The standard grey colour suits grey PVC pipe runs. Rubber-sealed for a watertight cap. Ideal for temporarily sealing stacks during installation or permanently capping unused branch ports.

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Aquaflow 110mm Pushfit Straight Coupling — Black

Double-socket pushfit coupling for joining two lengths of 110mm soil pipe. Accepts standard spigot ends. Twin rubber seals give a watertight joint with no cement. Leave a 10mm expansion gap on each spigot.

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110mm Double Socket 92.5° Pushfit — Black

Swept 92.5° double-socket bend for stack base transitions and near-horizontal offsets. The swept radius promotes flow and reduces blockage risk. Pushfit both ends — no adhesive required.

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Aquaflow 110mm Pushfit Adjustable Bend 0–45° — Black

Sets any angle from 0° to 45° — ideal where the soil run must avoid a joist or structural element. Fully adjustable before locking in position. Pushfit ends, no cement needed.

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APM Electricals — 24 Western Avenue, Acton, London W3 7TZ | Tel: 020 8702 8080 | www.apmi.uk