One thing, done properly
We do not sell a general drainage catalogue. Backflow prevention is the whole business, and that focus is the reason the range covers what it does: five valve families, dozens of connection variants, and bore sizes that step in millimetres rather than nominal jumps, because real drainage pipes are rarely perfect.
That specialisation shows up in the detail. Slide-direct models are selected on measured pipe outside diameter and grouped by pipe material. PVC, polyethylene, twinwall, clay, ductile iron and concrete each have their own table. Inline models are selected on measured bore, with +G gasket variants covering pipes above the standard range. Where a size falls between published models, we quote it.
Mark Radford fitting a 600mm duckbill valve, enabling land drainage works at Charlesland, Ireland. 1992
Rubber, Reinforced and Vulcanised
Our valves are built from layers of fabric-reinforced rubber, vulcanised into a single piece — the same principle as a modern tyre. There is no hinge to seize, no lubrication schedule, no actuator, no power supply. The rubber flexes to open under upstream head and closes the instant flow reverses.
That construction is what allows the valves to work where flap valves fail: submerged in tidal water, buried in shingle and silt, exposed to saltwater year-round, handling grit-entrained flows that would wear a metal seat. Materials are certified to EN 681-1:1996, types WC and WG. Fabricated valves carry a four-year warranty on registration and are designed for a twenty-year service life.
Maurice Radford who introduced Tideflex duckbill valves to Ireland in 1989. Everything here started with him going out and telling engineers there was a better valve than a flap.
Built for the people who specify it
Our customers are civil engineers, drainage designers and utility asset managers — the people who have to justify a component on a drawing and then live with it for twenty years. Everything we publish is written for that audience: full dimensional tables, bolt circle diameters, weights, cracking pressures, discharge coefficients by velocity, and downloadable STEP models for every stocked size.
Two companies, one range
Measurit Technologies Ltd (Ireland) owns the Check-Flex® brand and serves the EU market through check-flex.eu. Check-Flex Limited (UK) handles UK supply through check-flex.co.uk, established to keep post-Brexit trading and delivery straightforward for British customers. Same range, same stock, same engineers behind it.
We don’t hide the product behind sales calls
You should not have to give us your email address to find out a bolt circle diameter. Every dimension, weight, drilling pattern, cand discharge coefficient we hold is published on the datasheets and in the valve selector alongside live stock figures and downloadable STEP models. There is no registration, no gate, and no follow-up call.
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We stock valves
There are 2,500 valves on the shelf in Ireland, in sizes we chose ourselves. That is a substantial investment to make in a single product range, and we make it because we know what these valves do in the ground. We have fitted them, watched them work, and gone back years later to look.