Duckbill valves
Two lips, pressed together, that open under forward pressure and seal against backflow. Simple in principle, precise in practice.
Open this variantFlow control · valves and diaphragms
Valves and diaphragms.
A valve is judged on one thing: does it open and close the way it's supposed to, every time. That comes down to wall section, material hardness and consistency between batches. It's precise work in a forgiving material.
Why valves are different
The part is small. The function is everything.
A gasket that's slightly softer than specified usually still seals. A valve that's slightly softer opens at a different pressure, leaks back, or chatters. The margin for drift is much narrower, even though the material is the same.
That's why valve and diaphragm programmes get extra attention on three things: the exact durometer of each batch, the consistency of thin wall sections, and — for slit valves and duckbills — the quality of the slit or lip itself.
Most valves we make run in LSR, which suits thin sections and gives very consistent cure. Larger industrial diaphragms often run in compression, sometimes with fabric reinforcement.
We don't publish opening pressures or tolerances as selling points. We agree a functional test with you and run it on every batch.
Drill down
2 ways we run valves and diaphragms.
Each variant has its own page with the specifics: where it fits, how we run it and what to send us.
Diaphragms
A diaphragm flexes thousands or millions of times. Its life depends on material, section and how evenly it was moulded.
Open this variantWhat we make
Three families.
Duckbill valves
One-way valves that open under forward pressure and seal under back pressure. Used in dispensing, medical and appliance fluid paths. See duckbill valves.
Umbrella and check valves
A domed disc seated over ports that lifts under pressure. Compact and simple to assemble.
Diaphragms
Flat, domed or convoluted membranes for pumps, regulators and actuators. See diaphragms.
How we keep them consistent
Control the things that move the opening point.
Opening behaviour depends on geometry and material together. We control both and check the result.
Tool design for thin sections
Gating and venting placed so thin walls fill evenly and cure without knit lines across the working area.
Batch hardness checks
Durometer checked per batch against the agreed band, and recorded.
Slitting and lip finishing
Where valves need a slit, it's cut in a controlled fixture after moulding, then inspected.
Functional testing
An agreed crack-pressure or leak test on a sample from every batch, against your acceptance criteria.
To quote it
What we need.
The valve or diaphragm drawing
Or a sample of the current part if you're replacing a supplier.
The fluid and the environment
Water, air, food, medication, oil or chemicals, and the temperature range.
How it should behave
Roughly when it should open, how it should seal, and how you currently test it.
The paperwork
Whether you need a medical-grade material record or food-contact grade documentation.
Related routes
Where this connects.
LSR injection moulding
Two-part liquid silicone metered, mixed, injected cold and cured hot. The cleanest route we have for medical, wearable and electronics parts at…
Read moreMedical-grade manufacturing
Silicone moulding for medical device makers using medical-grade materials to a documented specification, with batch traceability from drum to…
Read moreCompression moulding
Solid silicone or rubber pre-formed, loaded into a heated steel tool, and pressed under cure. Sensible tooling cost, thousands of parts per tool, and…
Read moreDesigned and developed in the UK. UK moulding capability, with some higher-volume production placed with trusted partners where that's the right commercial answer.
Get in touch
Tell us the part, the volume, and the timeline.
Rough annual volume, target unit price, and any deadlines. That's enough to work out whether compression, LSR injection or something else is the right tool.
Real people, a real workshop
You deal with the people who make it.
No call centre and no middlemen. When you contact TCI Products, you speak to the team who design, build and check your mould.
- A real Warwickshire workshopUnit 15, Waterloo Park, Bidford-on-Avon, Alcester B50 4JG.
- Real people on the phoneCall the team on 01789 224228, Monday to Friday.
- The same team on every jobDesign, production and aftercare come from the people you see here.
- Part of TCI GroupFive specialist brands, one engineering team. Visit TCI Group.
Thomas LaneManaging Director
George PrestonDesign & Project Manager
Kelly BallingerHead of Partnerships
Jim AndertonProduction Manager
TheodoreEmployee Welfare