PVC-KG Non-Return Valve, Double Flap

  Datasheet (PDF)

The PVC-KG double flap non-return valve is engineered for civil and municipal gravity drainage infrastructure to prevent sewage backflow in buried non-pressure networks. Featuring dual independent swing flaps alongside a top-mounted manual locking lever, this unplasticised polyvinyl chloride component provides redundant backwater protection for buildings and utility lines. Designed for underground installation buried inside and outside structural footprints, it ensures dependable sealing up to 0.5 bar.

Technical specifications

The dual-flap configuration automatically prevents reverse flow in gravitational sewer lines, while an integrated manual emergency handle enables complete manual locking during inspection or maintenance. The internal chamber design maintains hydraulic capacity with minimal surface friction, preventing sediment deposition during standard wastewater discharge.

• Operating temperature: continuous service up to 40 degrees C, intermittent exposure up to 60 degrees C
• Operating pressure threshold: joints certified leak-proof up to 0.5 bar
• Chemical resistance: broad compatibility with acidic and alkaline media within pH 2 to pH 12
• Sealing ring specification: factory-fitted synthetic rubber (EPDM) compliant with EN 681-1
• Reaction to fire: class B2 normal flammability conforming to DIN 4102
• Material mechanical limits: raw PVC tensile yield strength greater than 45 MPa and elasticity modulus of approximately 3000 MPa

Applications

The unit is designed for non-pressure underground drainage and gravity sewerage networks in residential, commercial, and industrial facilities. Classified for application code UD, it is approved for underground installations located both inside building perimeters and externally in open soil.

Primary installations include sanitary drainage branches, stormwater collection networks, and basement protection points where heavy precipitation or surcharged main collectors risk backflowing into connected properties. It also functions as a physical barrier preventing rodent and vermin access from sewer mains into private plumbing infrastructure.

Materials and standards

Manufactured from robust orange-brown unplasticised polyvinyl chloride (PVC-U), the housing offers superior resistance to ground settlement, aggressive soil conditions, and internal chemical attack. The formulation provides a linear thermal expansion coefficient of 0.08 mm/mK and expected operational durability exceeding 50 years.

The valve incorporates socket joint connections equipped with pre-fitted EPDM elastomeric seals manufactured to EN 681-1, accommodating pipe alignment variations while maintaining complete joint tightness. Laying and backfilling procedures conform to standard underground sewer laying practices under SR EN 1610.