Essential Considerations for a ‘Safe and Successful’ Christmas Shutdown & Start-up
The festive shutdown is a gift for the safe and effective management of thermal fluids. Not only does it give you the chance to do critical preventative maintenance that will prevent incidents or slow their escalation, it also offers a golden window to test whether systems will react as you think they will when conditions change – as temperatures cool (in shutdown) and heat up (in start-up).
At TFS we work with manufacturing and process operations around the world, helping them get the most out of the unique opportunities shutdown brings without compromising on safety.
To start 2021 with your system in a better place than you left it in 2020, here are some of our key recommendations:
The Fluid: be prepared for change
As the system cools down, changes will occur to the oil. For example, fluid saturation levels reduce as oil cools which means it won’t hold the same amount of sediment in suspension, causing it to drop from tanks into circulation, into heat exchangers and around pumps.
Take the opportunity to filter fluids to both maintain thermal efficiency and protect the longevity of your [thermal fluid system] assets.
Similarly, the saturation level of water reduces so be prepared to have to remove free water and moisture from vessels, drain points buffers, deaerators and degassers.
The System
By far the greatest risk relating to thermal oil is the flammable atmosphere it creates when released from the system. Shut down is great time to repair any system integrity issues i.e. leaks!
Other important ongoing maintenance activities include clearing strainers and filters, ensuring circuits are able to breathe, cleaning and clearing deaeration pipes and identifying and removing ‘dead spots’.
System maintenance
Do those maintenance jobs that can only be done when the system has been shut down including:
- tank and vessel draining – removal of water and sludge
- installation of flood lines in safety valves
- checking and performance testing of hard to access sensors and devices
- removal of all oil-soaked insulation – upgrade to non-absorbent materials
Safety and performance testing – inline and external
Knowing how your system will respond in certain ‘unsafe’ conditions (under the cooling necessitated by lockdown) will give you confidence that it will do what you need it to in a real emergency. So, checking your system baseline, verify flowmeter ‘zero’ and ensure area/emergency stops, slam shuts and safety chains are all doing what they should.
Start-up
The golden rule is that you should never, ever have to bypass a safety device to get a system started. Ideally you will be doing a cold start-up to ensure you don’t put your system under too much thermal stress too early on.
The process:
- Mechanical warm up (running the pumps)
- Minimum flow achieved
- Slow ‘heated’ warm-up
- Secondary circuit introduction around 100 degrees C (212F)
- Monitor pumps / expansion
- Maintain heat up rate before going to full fire
‘Essential Considerations for a ‘Safe and Successful’ Christmas Shut-down & Start-up’ was the subject of a recent webinar delivered by our managing director, Richard Franklin.
It was part of an ongoing online programme designed to help process manufacturers learn more about the ways in which they can minimise the risks associated with the operation of thermal fluid systems and also run them efficiently, cost-effectively, safely and with statutory compliance.
It can be viewed here, along with others in the series. New webinars will be taking place at regular intervals and are easily accessible by registering here, where you will also be able to see details of forthcoming events.
For further details, please visit www.thermalfluidsolutions.com/webinars/ or call 44(0)1298 815862 (UK) or +1 713 253 3272 (US)