PVC Eccentric Reducer Bush Water Adhesive Fittings 50 75 110mm Drain Waste Vent

A concentric reducer bush centres the smaller bore inside the larger one, so the pipe centreline shifts but both top and bottom change equally. An eccentric reducer bush offsets the bore so that one side (typically the bottom/invert) stays flat. This is critical in horizontal DWV runs where you need to maintain a consistent invert level to preserve gravity flow and avoid creating a low-point that traps solids or water.

Match the larger socket to your existing pipe OD. If your main soil or waste pipe is 75mm (~3"), choose the 75 × 50mm bush. If it is 110mm (~4") — the most common residential soil pipe size — choose the 110 × 50mm bush. The 50mm spigot end connects to standard 50mm (~2") waste pipe from basins, baths, or showers.

uPVC DWV fittings are routinely used in below-slab drainage when properly bedded and backfilled per local plumbing codes. The solvent-cement joint forms a rigid, watertight bond suitable for buried service. Always verify that the fitting meets your local authority's approved product list before installation in concealed or underground locations.

Use a uPVC-rated solvent cement (often labelled "PVC pipe cement" or "water adhesive") appropriate for DWV applications. In many regions a dedicated PVC primer or cleaner is recommended or required by code to degrease and soften the mating surfaces before cementing. Follow the cement manufacturer's cure time — typically 15–30 minutes before handling and 24 hours before pressure or flow testing.

uPVC has good resistance to dilute acids, alkalis, and the range of household cleaning products, detergents, and drain cleaners typically encountered in residential waste systems. It is not suitable for concentrated solvents, ketones, or aromatic hydrocarbons. For commercial or industrial waste streams containing aggressive chemicals, confirm chemical compatibility before specifying.

Cut the pipe square and deburr the end. Dry-fit first to confirm depth and alignment. Apply primer/cleaner to both the spigot OD and socket ID, then apply an even coat of solvent cement to both surfaces. Push the spigot firmly into the socket with a slight twist, hold for 30 seconds, and wipe away excess cement. Avoid disturbing the joint for at least 15 minutes. A small bead of cement around the socket mouth confirms full coverage.

Yes. uPVC eccentric reducer bushes are suitable for vent stack size transitions as well as waste and soil lines. In a vertical vent application the eccentric offset is less critical than in horizontal runs, but the fitting performs identically. Ensure all vent connections comply with your local plumbing code regarding minimum pipe diameters and vent termination requirements.