Double Pipe Trap McAlpine HC7+DO2-U 1.5" – plumbing syphon for dual waste

McAlpine HC7+DO2-U 1.5" is a double pipe trap designed to connect and seal two drainage outlets into a single waste line. Intended for installations such as basins, bidets or small appliances, this plumbing syphon provides a water seal that prevents sewer gases from entering premises while combining two 1.5" inlets into one outlet. The unit is manufactured to fit common domestic and light commercial drainage systems and is suitable where space constraints require a compact dual-waste solution.

Advantages

The dual inlet design allows two fixtures to share a single drain without compromising the trap seal. Constructed from corrosion-resistant plastic, the trap offers reliable water retention and low maintenance compared with metal alternatives. Compact dimensions and simple connections make installation straightforward in tight under-sink spaces. The removable access point simplifies cleaning and clearing of blockages, reducing service time.

Suitable for

• Bathroom basins with a combined overflow or secondary outlet
• Bidets paired with a nearby washbasin sharing the same drain
• Small domestic appliances that require connection to a sink waste
• Renovation projects needing a compact dual-waste trap under limited space

Key specifications

• Connection size: 1.5" inlets (dual) and compatible outlet for standard sink waste
• Type: Double pipe (dual waste) P-trap / syphon
• Material: corrosion-resistant plastic
• Seal: water trap to prevent sewer gas ingress
• Access: removable section for cleaning and maintenance
• Installation orientation: under-sink horizontal/vertical configurations where applicable

How to use

Position the double trap beneath the fixtures so both 1.5" inlets align with the basin and secondary outlet. Ensure pipe ends are clean and free of debris before making connections. Fit each inlet to the corresponding waste tailpiece and secure using the appropriate push-fit or compression fittings compatible with the trap. Connect the outlet to the building drain, check that the trap is level and that the removable access section is in place. Run water to confirm proper drainage and verify there are no leaks at the joints.

Usage recommendations

Regularly inspect and, if necessary, remove the access section to clear accumulated debris and maintain the water seal. Avoid using chemical drain cleaners directly in large quantities as they can shorten the service life of plastic components. For installations with longer horizontal runs or where venting is limited, consult local plumbing codes or a qualified installer to ensure correct trap configuration and compliance.