# valve

/ˈvæɫv/ (US) · /vˈælv/ (UK)

Source: https://englishreference.com/word/valve
Updated: 2026-06-19

## Senses

### 1. mechanical device

noun · CEFR B2

a mechanical part in a pipe or machine that opens and closes to control the flow of water, gas, or air.

For teachers: a mechanical device used to regulate the flow of fluids or gases within a system of pipes or machinery.

- He turned the valve to shut off the water before fixing the leak.
- The engineer adjusted the pressure relief valve to ensure the steam did not exceed the safety limits of the boiler system.

Usage: Often used with verbs like 'open', 'close', or 'turn'.

### 2. anatomy

noun · CEFR B2

a part of the heart or a vein that keeps blood flowing in the right direction.

For teachers: a membranous fold or flap in a hollow organ or vessel that maintains the unidirectional flow of bodily fluids.

- The doctor checked the patient's heart valves to make sure they were working correctly.
- Mitral valve prolapse occurs when the flaps of the heart's mitral valve do not close smoothly or evenly.

Usage: Commonly appears in medical contexts regarding the heart or circulatory system.

### 3. vacuum tube

noun · CEFR C1 · British English · Technical

an old-fashioned electronic part used in early radios and computers.

For teachers: an electron tube consisting of a sealed glass or metal enclosure used to control electron flow.

- The old radio still uses glass valves instead of modern chips.
- Early mainframe computers relied on thousands of thermionic valves, which generated immense heat and required frequent replacement.

Teaching tip: This is the standard British term for what Americans call a 'vacuum tube'.

### 4. biology

noun · CEFR C2 · Technical

one of the two parts of a shell, like those on a clam or an oyster.

For teachers: one of the distinct, usually hinged, shells of a bivalve mollusc or the shell-like parts of certain other organisms.

- The clam uses strong muscles to keep its two valves tightly shut.
- The fossil record provides clear evidence of how the hinge mechanism between the two valves evolved over millions of years.

### 5. to regulate flow

verb · CEFR C2 · Formal

to control the flow of something using a valve.

For teachers: to regulate or control the passage of a fluid or gas through the use of valves.

- The system is designed to valve the gas automatically if the pressure drops.
- The technician had to manually valve the intake to prevent the chemical solution from overflowing the primary tank.

## Examples

- The heart has four valves that keep blood flowing correctly.
- The plumber replaced a faulty valve in the heating system to stop the water from leaking.
- In many biological systems, a damaged valve can lead to significant pressure imbalances, as the mechanism fails to prevent the backflow of essential fluids through the primary vessels.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.