Air admittance valve McAlpine 32/40 mm model 5510 for soil and waste plumbing

The McAlpine air admittance valve model 5510 is designed for soil and waste plumbing systems and fits 32 mm and 40 mm pipe connections. It admits air into the drainage system to prevent negative pressure that can siphon water from traps, helping to maintain water seals and reduce the risk of sewer gas entering occupied spaces. The valve is compact and intended for installation in locations such as beneath worktops, in service voids or enclosed cupboard spaces where a traditional roof vent is impractical.

Advantages

This air admittance valve provides controlled venting without the need for roof penetration, simplifying installation and reducing disruption to the building envelope. Its compatibility with both 32 mm and 40 mm pipe sizes makes it versatile for a range of domestic and light commercial drainage layouts. The valve reduces odours by allowing air ingress while preventing efflux of foul gases, and its compact design allows concealed installation in tight spaces.

Suitable for

• Domestic kitchen, bathroom and utility room drainage systems
• Light commercial washroom installations where roof venting is impractical
• Retrofit projects and renovations where adding a vent stack is difficult
• Installation under worktops, in service voids or enclosed cupboard spaces

Key specifications

• Compatible pipe sizes: 32 mm and 40 mm
• Function: admits air to prevent trap siphoning and maintain trap seals
• Intended use: soil and waste plumbing systems for domestic and light commercial applications
• Installation location: concealed or accessible service voids, under worktops or cupboards

How to use

Install the valve onto the waste or soil pipe using the appropriate 32 mm or 40 mm connection and ensure it is positioned vertically and accessible for inspection. Follow local plumbing regulations and manufacturer guidance to ensure correct orientation and secure fittings. The valve operates automatically: it opens to admit air when negative pressure occurs in the drainage system and closes to prevent the escape of sewer gases when pressures equalise.

Usage recommendations

Use this air admittance valve only where permitted by local building and plumbing codes. Ensure periodic visual inspection to confirm the valve remains unobstructed and replace if signs of wear or failure appear. Avoid installing in locations prone to freezing or where direct contact with liquids could affect operation.