---
title: Marking
description: "The equipment marking must be to IEC 60079-2 & IEC 60079-0, and contain the following information: 1. The manufacturers name 2. Model number, type and serial number 3. The symbol Ex, followed by the pressurisation types i.e. pxb, pyb, or…"
url: "https://www.eicstech.com/kb/pressurisation-ex-p/basics-on-marking-in-pressurisation/"
updated: "2022-06-01"
category: Explosion Proof Basics / Pressurisation (Ex p)
---

# Marking

The equipment marking must be to IEC 60079-2 & IEC 60079-0, and contain the following information:

1. The manufacturers name
2. Model number, type and serial number
3. The symbol Ex, followed by the pressurisation types i.e. pxb, pyb, or pzc
4. The gas group symbol II, temperature class, or the maximum surface temperature, or both, e.g. T3, or 200°C, or 200°C (T3)
5. The certificate number
6. The internal free volume excluding the ducts
7. The protective gas (when a gas other than air is used)
8. Details of the minimum purge requirements
9. The minimum and maximum permissible over-pressure
10. The minimum flow of protective gas
11. The min. and max. supply pressure to the system
12. The maximum leakage rate from the enclosure
13. The temperature or temperature range of the safe gas at the inlet duct
14. The point(s) where the pressurisation is to be monitored.

**IEC 60079-17:2013 Table 3**

**Inspection schedule for Ex “p” and Ex “pD” installations**

|  | ** Check that :** | **Grade** | **of** | **inspection** ** ** |
| --- | --- | --- | --- | --- |
|  | ** X = required** |   |   |   |
| **A** | **EQUIPMENT** | **D** | **C** | **V** |
| 1 | Equipment is appropriate to the EPL/Zone requirements of the location | X | X | X |
| 2 | Equipment gas group is correct | X | X |   |
| 3 | Equipment temperature class or surface temperature is correct | X | X |   |
| 4 | Equipment circuit identification is correct | X |   |   |
| 5 | Equipment circuit identification is available | X | X | X |
| 6 | Enclosure, glasses and glass-to-metal sealing gaskets and/or compounds are satisfactory | X | X |   |
| 7 | There are no unauthorised modifications | X |   |   |
| 8 | There is no evidence of unauthorised modifications |   | X | X |
| 9 | Lamp type, rating and position are correct | X |   |   |
| **B** | **Installation** | ** ** | ** ** | ** ** |
| 1 | Type of cable is appropriate | X |   |   |
| 2 | There is no obvious damage to the cable | X | X | X |
| 3 | Earthing connections, including any supplementary earthing bonding connections, are satisfactory, for example connections are tight and conductors are of sufficient cross-section | X | X | X |
|   | Physical check | X | X | X |
|   | Visual check | X | X | X |
| 4 | Fault loop impedance (TN systems) or earthing resistance (IT systems) is satisfactory | X |   |   |
| 5 | Automatic electrical protective devices operate within permitted limits | X |   |   |
| 6 | Automatic electrical protective devices are set correctly | X |   |   |
| 7 | Protective gas inlet temperature is below maximum specified | X |   |   |
| 8 | Ducts, pipes and enclosures are in good condition | X | X | X |
| 9 | Protective gas is substantially free from contaminants | X | X | X |
| 10 | Protective gas pressure and/or flow is adequate | X | X | x |
| 11 | Protective and/or flow indicators, alarms and interlocks function correctly | X |   |   |
| 12 | Conditions of spark and particle barriers of ducts for exhausting the gas in hazardous area are satisfactory | X |   |   |
| 13 | Specific conditions of use (if applicable) are complied with | X |   |   |
| **C** | **ENVIRONMENT** |   |   |   |
| 1 | Equipment is adequately protected against corrosion, weather, vibration and other adverse factors | X | X | X |
| 2 | No undue accumulation of dust and dirt | X | X | X |

(D=detailed, C=close, V=visual)