---
title: "Solenoid valve"
description: "A solenoid valve is the electrically-actuated pilot device that admits compressed air to a sonic horn on command from the cycle controller. The valve opens for the programmed pulse duration (typically 5–15 seconds), letting plant air at 4–7 bar drive the horn's diaphragm into resonant oscillation. When the valve closes, the air supply is cut and the horn falls silent until the next pulse."
canonical_url: "https://sylio.co/glossary/solenoid-valve"
last_updated: "2026-06-28T02:29:28.546Z"
---

A **solenoid valve** is the electrically-actuated pilot device that admits compressed air to a [sonic horn](/glossary/sonic-horn) on command from the [cycle controller](/glossary/cycle-controller-sequencer). The valve opens for the programmed pulse duration (typically 5–15 seconds), letting plant air at 4–7 bar drive the horn's [diaphragm](/glossary/diaphragm-horn) into resonant oscillation. When the valve closes, the air supply is cut and the horn falls silent until the next pulse.

## Specification

For most industrial sonic-horn installations, the solenoid valve is:

- **ATEX / IECEx certified** for the local hazardous-area classification
- **Sized** for the horn's peak airflow (8–14 Nm³/min typical)
- **Quick-exhaust** type, to allow rapid pressure drop at the end of each pulse
- **Voltage-rated** for the site's instrument-control voltage (typically 24 VDC or 110/230 VAC)
- **IP65 or IP66** weatherproof if mounted externally

## Wear and replacement

The solenoid valve is the most-replaced wear part on the periphery of an industrial sonic horn — typical service life of 1–3 years before coil or seat replacement. Routine inclusion in the spares package is standard practice.

## Related terms

- [Sonic horn](/glossary/sonic-horn)
- [Pneumatic acoustic cleaner](/glossary/pneumatic-acoustic-cleaner)
- [Cycle controller / sequencer](/glossary/cycle-controller-sequencer)
- [Compressed air](/glossary/compressed-air)