A.D.S. Wet Welding

Abstract The purpose of this paper is to discuss wet welding using fully anthropomorphic atmospheric diving suits and offer proof that wet welding operations are both feasible and practicable using ADS. Furthermore, future welding processes for deepwater applications will be shown to be well within ADS capabilities. Details of the criteria to be met for successful ADS wet welding is discussed, including specific task completion abilities such as connecting earth clamps, changing rods and effecting a weld. The technique and actual operation of wet welding by the ADS will be described in detail. This will include safety and practical requirements and how to successfully weld. Underwater cutting and burning will also be addressed. Finally, the subject will show that ADS is fully capable of handling deepwater maintenance and repair with a look toward future welding technology. Introduction Maintenance and repair is becoming costly and difficult as offshore facilities move into deeper water. Saturation diving and vessel costs are enormous while welding technology has not achieved an acceptable level of performance. Therefore, much incentive exists for developing a cost-effective maintenance and repair system. Ocean ring has taken the first step by examining the feasibility of performing deepwater maintenance and 'repair with an Atmospheric Diving Suit (ADS). Underwater cutting and welding trials were first conducted in 1979 with impressive results. The manipulative capabilities of the articulated arms were more than adequate to perform underwater cutting and burning. Wet welding proves to be the most difficult task with additional work required for acceptable procedures under operational conditions. Patching, attaching pad eyes and anodes, and spot welding can be achieved with reasonable success. However, since wet welding is limited to 200 feet and dry welding is not cost-effective, welding technology lags considerably behind operational considerations for deepwater maintenance and repair. Major welding research is concentrated on new methods for deepwater application such as friction, termite, and explosive welding. While significant advances have been made with these processes, they fall short of qualifying to API specifications. Fortunately, these techniques are mechanically simple to perform and are well within the capability of ADS. Similar work methods are demonstrated with explosives by ADS. The mechanical manipulation of the materials and equipment are a straight forward exercise of ADS intervention engineering. Therefore, as new welding techniques are perfected for deepwater maintenance and repair, ADS will be fully capable of performing the work. Welding With Ads Currently underwater welding is split into three methods:HyperbaricPelionHydrowe1d The Pelion process is the one employed for use with the ADS, as in this process effective welding is carried out without the use of any mechanical shield to protect the arc from the surrounding water. The arc itself produces a shield of superheated steam that isolates the arc. The process is very similar to that of surface arc welding.