---
title: "Controls & Safety Devices"
description: "The level of overpressure will be monitored by a pressure sensor or switch located in the enclosure, at the most difficult point at which to maintain overpressure. The rate of flow through the enclosure will be monitored by a flow-rate…"
url: "https://www.eicstech.com/kb/pressurisation-ex-p/basics-on-control-safety-devices-in-pressurisation/"
updated: "2022-06-01"
category: Explosion Proof Basics / Pressurisation (Ex p)
---

# Controls & Safety Devices

The level of overpressure will be monitored by a pressure sensor or switch located in the enclosure,
at the most difficult point at which to maintain overpressure.

The rate of flow through the enclosure will be monitored by a flow-rate sensor or switch. A pressure gauge is also desirable and should be located where it can be easily read.

When the safe gas is provided from a compressed-air system or cylinders a pressure relief valve should be installed in case of failure of the regulator.

Typical pressurisation monitoring etc.

1. Over-pressure monitoring device
2. Protective gas flow-rate monitoring Device.
3. Pressure gauge
4. Pressure relief valve: setting 75% of maximum declared safe over-pressure

![typical presurisation monitoring](https://www.eicstech.com/wp-content/uploads/2022/06/controls-and-safety-devices.png)

![](https://www.eicstech.com/wp-content/uploads/2022/06/pressurisation-control-system.png)

## Pressurisation Control Systems – marking

A purge and pressurisation control system with a separate certificate is marked as**associated equipment.**

- If the control system is for use in the hazardous area, the marking is: **Ex [p]**

- If the control system is for use in a non-hazardous area, marking is: **[Ex p]**