This month, ABS has updated their much cited publication, Guide For Lay-Up and Reactivation of Mobile Offshore Drilling Units. Over the past two years, we have written white papers on this topic in regard to using desiccant dehumidifiers for rig lay-ups. The revisions to the ABS guide echo what we have been saying and what we know will work in these applications.
We have outlined many reasons why we recommend using desiccant dehumidifiers rather than air conditioning for rig lay-ups. For further clarification with regard to rig stacking and machinery space preservation, ABS states in Section 2, 3.5, “Continuous heating for all machinery spaces is to be provided to maintain a temperature a few degrees above atmospheric; or alternatively, complete dehumidification at 35% to 45% relative humidity is normally required to prevent sweating or humidity damage.”
Furthermore, in Section 3, 1.17, ABS outlines the procedures and standards for preservation and again make the same recommendation as quoted above.
Out of the entire 21-page ABS guide, dehumidification is referenced a total of 18 times. It is truly the best way to keep your rig’s quarters, machinery spaces, and equipment in excellent shape in order to make reactivation go more smoothly.
In contrast, the single reference to air conditioning in this new ABS guide refers to powering down and deactivating the AC systems. Air conditioning will not accomplish the desired preservation goals.
Clearly ABS supports what Eldridge has been saying over the past 18 months: dehumidification with desiccant dehumidifiers is the preferred and optimal method of stacking a mobile offshore drilling rig.
For more details about how to implement a desiccant dehumidification system in your rig stacking application, please see these two Eldridge articles:
Best Practices for Dehumidification of a Mobile Offshore Drilling Rig Lay-Up
Why You Should Be Using Desiccant Dehumidifiers Instead of Air Conditioning for Offshore Lay-Ups
For a free estimate, contact us and we will be happy to discuss your MODU lay-up needs.