Check-Flex Rubber Check Valves stop backflow.

Responsive, Robust and Reliable

Check-Flex is the trusted partner for intelligent valve solutions ensuring reliable stormwater flow control and flood prevention.

Inline Check
Valves

Cut-away blue pipe with black flexible liner, dark water gushing out, showing internal clamp.

Duckbill Check Valves

Black Check-Flex valve with dimensions.

Designing with Rubber Valves

With decades of experience in stormwater management, Check-Flex delivers advanced valve and flow control systems that protect infrastructure and communities. Trusted by engineers and municipalities across the UK and Ireland, we provide reliable solutions — from smart flow regulators to custom flood prevention systems.

Inline Check Valves

Duckbill Check Valves

Designing with Rubber Valves

A worker in a hard hat and high-vis vest stands in a trench next to a large pipe being lowered.

Check-Flex® Rubber Check Valve

The Check-Flex® line of rubber check valves offers a cost-effective and optimal solution for all backflow prevention needs.

Available in seven models and six connection styles, the size range is extensive, from 50mm up to 3000mm.

These rubber valves provide an effective backflow solution that is maintenance-free and requires no power, offering years of reliable service.

Check-Flex has positively transformed communities by delivering crucial keystone flood prevention and sustainable stormwater solutions, a success achieved through collaboration with top-tier design teams.

Discover Inline Check Valves
A black pipe emerges from a concrete structure, secured by metal bands, discharging onto a gabion rock mattress.

Duckbill Valve

The Check-Flex® line of rubber check valves offers a cost-effective and optimal solution for all backflow prevention needs.

Available in seven models and six connection styles, the size range is extensive, from 18mm up to 2400mm.

These rubber valves provide an effective backflow solution that is maintenance-free and requires no power, offering years of reliable service.

Check-Flex has positively transformed communities by delivering crucial keystone flood prevention and sustainable stormwater solutions, a success achieved through collaboration with top-tier design teams.

Discover Duckbill Valves
Traceable, High-Quality Materials
Valves are constructed using traceable materials. EN 681-1:1996 — Types WC and WG Chloroprene (Neoprene) and EN 1.4404 (316L) stainless steel.

Fully Defined Elastomer Properties per ASTM D2000
The ASTM D2000 classification system provides a complete description of the elastomeric material properties. The Check-Flex® material specification is strictly controlled for key properties, including hardness, modulus, heat, ozone, and UV resistance, oil resistance, and compression set.

Standard and Optional Elastomer Materials
The standard elastomer used is Chloroprene (Neoprene). This material is highly valued for its exceptional weathering resistance, durability, and flexibility. In sewer applications, Chloroprene remains unaffected by H₂S and other common contaminants. For high-risk environments, such as industrial plants and fuel oil bunds, alternative materials can be used for valve construction. (e.g. EPDM, Nitrile and VITON)

Integrated and Controlled Manufacturing Process
The manufacturing process, from calendering to vulcanization, is integrated, which guarantees consistent production and adherence to individual valve design specifications.

ISO 9001 Certified Quality Management
The manufacturer holds an ISO9001 Certificate, accredited by IAF to National Standards, which covers the design, development, and production of rubber check valves.
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Independently Verified Hydraulic Performance
Critical hydraulic performance metrics, specifically exit velocity and headloss, are independently verified at the Utah Water Research Laboratory

Rigorous Backpressure and Valve Opening Testing
Backpressure and valve opening characteristics are subject to rigorous in-house testing

Integrated Design and Manufacturing Facility
Check-Flex® valves are designed and manufactured in Korea by an integrated specialist facility. This facility manages the entire production process, from calendering to vulcanization, which ensures consistent manufacturing within the design specifications of each individual valve.

Corrosion-Resistant Metal Components
The standard metal is 316L Stainless Steel EN 1.4404, with Super Duplex grades available for enhanced corrosion resistance in marine environments.

Cost-Efficient Injection-Moulded Valve Production
The G5-RESI, G5M, and G3M small moulded valves are manufactured using injection moulding, resulting in lower production costs, refer to specific valve model information.