Pressurisation Ex p
Pressurisation is a technique of guarding against the ingress of the external atmosphere into an enclosure, by maintaining a protective gas at a pressure above that of the external atmosphere.
Testing technique
Pressurisation is a technique of guarding against the ingress of the external atmosphere into an enclosure, by maintaining a protective gas at a pressure above that of the external atmosphere.
The difference in behaviour of potentially-explosive gases (Group I and Group II) and dusts (Group III) is recognised in the standard. Certification may cover more than one type of Group.
Testing to standards
The International Standard IEC 60079-2 or Australian/New Zealand Standard AS/NZS 60079.2 specifies requirements for design, construction and testing of Ex equipment and Ex components for type of protection Ex p. This standard is always applied together with IEC (or AS/NZS) 60079-0 – explosive atmospheres equipment – general requirements.
The International Standard IEC 60079-13 or Australian/New Zealand Standard AS/NZS 60079.13 specifies requirements for design, construction and testing of pressurized room Ex p and artificially ventilated room Ex v. Similarly, this standard is always applied together with IEC (or AS/NZS) 60079-0 – Explosive atmospheres equipment – general requirements.
Protection types
There are three protection types of pressurisation:
- 'pxb' applies to Group I, II and III, Equipment protection level EPL Mb or Gb or Db, respectively
- 'pyb' applies to Group II and Group III, Equipment protection level EPL Gb or Db respectively. A prerequisite requirement is that that all internal devices to the pressurized enclosure shall have minimum Equipment protection level EPL Gc or Dc
- 'pzc' applies to Group II and Group III, Equipment protection level EPL Gc or Dc respectively.
Pressurisation may be applied to individual enclosures containing electrical control equipment or to single motor.
A control room is an example of a pressurized room located in a hazardous location, that may house variety of electrical equipment. The control rooms may be purged with fresh air and maintained pressurised.
Types of tests
Here are some of the main tests:
thermal tests (temperature rise test)
resistance to Impact test
degree of protection test (IP) by enclosure
maximum over-pressure test
leakage test
purging and dilution tests
verification of Safety devices.
Enquire about pressurisation Ex p test
Getting the test results
The results of our testing are presented in a test report that is endorsed by our local Australian laboratory accreditation body, NATA (National Association of Testing Authorities, Australia).
When product sample testing, design assessment (Ex test report) and quality assessment (quality assessment report) are successfully completed, an Ex Certificate of Conformity (IECEx or ANZEx) is issued by TestSafe.
Help and support
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