Cleaning Up: Purged and Pressurised Sample Container Washing System
Working with an Automation and Control company to create a custom solution for sample bottle washing systems
Overview
The client designs, manufactures and installs factory automation. Their product needed a hazardous area control system for washing sample bottles within a refinery. The area is designated Class I Div 1, with a significan risk that potentially combustible gases are present in the air.
Project Brief
An industrial washing system for use in refineries had already been created by the client, although it was only suitable for use in Safe Areas. They required a custom purge and pressurised enclosure for upgrading to Class 1 Div1 (Zone 1) area. The enclosure needed to contain the controls and electronic connections to prevent potential combustible gases in the environment from interacting with the control panel.
Challenges
- Comprehensive certifications were needed as their equipment will be used globally in refineries.
- The solution needed to meet both Class I Div 1 & International Zone 1 specifications.
- The application requires the ability to cut power if the pressure inside the control enclosure is lost, in order to remain compliant with the applicable codes and standards.
- The customer also required the ability to depressurize the enclosure without cutting the power, due to routine maintenance of the industrial washing system.
Solution
Explosion-proof enclosures could not be considered as the client need constant access to the controls. The Purge and Pressurisation solution gives them the ability to access to the inside of the enclosure, whilst protecting the electronics from combustible gases. Having an Ex p solution also reduced costs associated with installling an HMI.
Outcome
- MiniPurge Type X, Leakage Compensation style was chosen as it supports the required certifications and is suitable for Class I, Div 1 and Zone 1 areas.
- Stainless Steel Housing was selected to provide durability with an industrial environment as well as being aesthetically pleasing when mounted to the customer’s control system.
- Pneumatic Output from the purge system was selected to interface with the Interface unit (MIU) needed to engage power after a successful purge, and disengaged power upon loss of pressure.
- A key-operated manual override was added to the MIU, to control power when servicing the control enclosure, subject to suitable risk assessment and permitting arrangements.