The McAlpine MacTun-2 is a highly specialized plumbing fitting that intelligently combines a traditional tundish with a dependable non-return valve, engineered to manage fluid discharge safely. It utilizes a sophisticated internal silicone membrane that automatically parts to allow high-temperature or pressurized water to flow freely into the waste pipe, before immediately sealing shut. This self-closing action creates an impenetrable barrier that stops dangerous sewer gases and foul odours from traveling back up the pipework into the habitable space. Crucially, the membrane design entirely avoids the use of mechanical springs, rendering the unit completely immune to the seizing effects of limescale accumulation in hard water regions.

Designed for supreme versatility, this fitting accepts a 15mm or 22mm inlet and connects directly to a standard 1 1/4-inch waste outlet. Because the internal membrane generates zero hydraulic resistance, water discharges smoothly without aggressive splashing, negating the need to install a secondary splash shield. Capable of withstanding boiling water up to 100 degrees Celsius, it is an essential safety component for unvented hot water cylinders, boilers, PRV valves and air conditioning condensate lines. The transparent upper section can be quickly unscrewed to allow installers instant access for visual inspection and cleaning.

Q: Does the internal valve mechanism rely on a metal spring?
A: No, it utilizes a spring-free silicone membrane, ensuring it remains unaffected by hard water scale.

Q: Can this tundish be connected directly to a soil pipe?
A: Yes, the self-closing membrane securely blocks any foul sewer gases from entering the building.

Q: What sizes of discharge pipe can the inlet accept?
A: The specialized inlet is designed to securely accept both 15mm and 22mm copper or plastic pipework.

Q: Is it necessary to install a separate splash shield?
A: The zero-resistance membrane design prevents splashing, completely removing the need for an additional shield.