FloPlast Universal Compression Reducer – WC38 40mm

Basin into bath waste without glue: the FloPlast Universal Compression Reducer joins a 40mm waste to a 32mm one using Compression nuts and seals, so no solvent is needed. It is the WC38, sized 40mm x 32mm.

When to use the FloPlast Universal Compression Reducer

Basins run in 32mm, while sinks, baths and showers use 40mm. Where a basin joins a bath waste, or a basin run needs to step up a size, this fitting makes the change. Compression joints are a good choice when you are not sure what make of pipe is already there.

Cut both pipes square and take off the burrs. Fit the right size nut and seal to each pipe, push them fully into the reducer and tighten by hand, then a small extra turn.

Do not overtighten. Crushing the seal causes leaks rather than stopping them.

Keep the run falling continuously through the reducer, and clip each side so the joints stay in line.

Specification

• Brand: FloPlast
• Range: Compression Waste (white)
• Maker code: WC38
• Material: White polypropylene
• Connection: Compression nut and seal at the 40mm and 32mm ends
• Sizes: 40mm x 32mm
• Standard or approval: BS EN 1451-1 in the FloPlast 2026 list
• Suitable for: Stepping a 32mm basin waste up into 40mm
• Max temperature: Continuous discharge up to 70°C to 75°C

Common Questions

Can I run a 32mm basin waste into 40mm pipe?

Yes, and the WC38 is the fitting for it. Going up a size is fine; going down from 40mm to 32mm on a sink or bath waste is not, because it can slow the flow and block.

Does the WC38 need different nuts on each end?

It comes with the right nut and seal for each end already. Just make sure the 32mm pipe goes into the small end and the 40mm pipe into the large end.

Will it join Push Fit pipe to Solvent Weld pipe?

Yes. Compression ends grip plain plastic waste pipe from either system, which is why FloPlast suggest a Compression fitting to link the two.

Reducers from our Glasgow counter

Other Compression waste fittings are in the Flexible range. Find Plumb Parts at 555 South Street, Glasgow G14 0QX, with doors open Mon-Fri 8am-5pm and Sat-Sun 8am-1pm, or order on the website for collection.

Datasheets

• FloPlast Unicom Compression Waste Leaflet (PDF)