Controlling ambient parameters is central to ensuring a fluid system is running smoothly. If a drastic change in temperature occurs—and isn’t planned for—it can amplify the harmful effects of the fluid on its surrounding system. For example, corrosivity and pressure are positively correlated with an increase in temperature, and accelerated wear could arrest operations without immediate maintenance. Temperature swings in the opposite direction can be equally destructive; any time a fluid experiences a phase change in a container that it is not designed to facilitate, the potential for damage increases.
In Edmonton, refinery winterization programs provide a necessary level of protection to equipment that might otherwise fail due to temperature extremes and resultant damage.
For lines exposed to winter temperatures well below freezing, insulation alone may not be enough. An active heating element can be used to prevent disruptions in tubing used to transport process media for analytical purposes. While freezing is the more catastrophic mode of failure, a decrease in viscosity due to a temperature drop can just as easily arrest operations and render a shutdown. The heating elements of the traced tubing come in two general styles:
Insulation and sealing are also important to the efficiency and longevity of heat-traced lines. Heat-shrink end- and entry-seal boots create waterproof seals when transitioning to or from enclosures. Preventing moisture ingress is especially important for electrical trace tubing, which could electrically short in the proximity of fuel sources.
Steam jacketed lines are also an option for winterization of piping. As opposed to heat traced lines where the fluid and heating element are in separate lines bundled together, steam jacketing has the fluid line directly encapsulated by the steam. This setup allows for an extremely large heat transfer surface, significantly increasing the thermal flux capability.
For every steam traced line in your system, steam traps will be a necessity. The steam trap is used in heating systems to separate between condensate and steam; they sit at a low point in the system to be able to effectively remove condensate and non-condensable gaseous mixtures. In fact, steam traps should be utilized every hundred feet of heated line or in the event of turns and elevation changes in the mainline. Further, steam traps should be present before any valves to remove condensate from the line—especially in the case of relief valves. This will help prevent the presence of a freeze leading to a rupture.
Without appropriate condensate removal, it is possible that the condensate experiences enough acceleration in the piping to create water hammer, which can lead to significant damage to equipment as well as present a major hazard to operators. In the event of a realized water hammer in extreme weather conditions, there are likely to be additional knock-on effects within the system, such as increases in viscosity in process lines or perhaps freezing that leads to more rupture events.
Best practices to ensure maximum condensate removal will rely on several factors:
Winterization is a wide-reaching process, and heat traced lines and steam trap implementation only cover a small portion of the necessary procedures to prevent downtime or system failure. Below is a noncomprehensive list of some additional miscellaneous processes to consider that help protect refineries against the extremes of Edmonton’s winter temperatures:
When it comes time to begin your winterization preparation, consult with an Edmonton Valve & Fitting Field Advisor. Our Field Advisors have a wealth of experience in leak detection and repair, in addition to general fluid system knowledge, that they can apply to ensure your system is prepared for the rigors of winter. Whether you’re in need of a new part, or a helpful pair of eyes to analyze, assess, and redress your refinery winterization programs, look no further than Edmonton Valve & Fitting.