56" Tethered Tecno Plug and 56" Door Plug, Saudi Arabia

STATS has successfully completed a trap valve changeout scope for a major Saudi Arabian client using a 56" Tethered Tecno Plug® and 56" Door Plug. 

The client had a requirement to replace a 56” pipeline receiver scraper trap valve in Saudi Arabia. A critical project requirement was to carry out the replacement without shutting down, purging, flushing or venting the entire 56" pipeline.

STATS were approached to engineer a solution whereby an isolation tool could be deployed to allow the safe replacement of the trap valve. Following a comprehensive engineering study and detailed site survey, STATS proposed and custom-designed a 56" Tethered Tecno Plug solution tailored specifically for this application.

The STATS Tethered Tecno Plug isolation system features two integrated isolation modules, engineered to deliver a safe and controlled pipeline isolation. The first module, known as the Door Plug, replaces the scraper door and provides the primary isolation. Once primary isolation is confirmed, the second module - The Tecno Plug is advanced to its designated set location immediately downstream of the 56" scraper trap valve. 

Both modules are designed to deliver a fail-safe double block and monitor isolation. Each unit features a dual-seal configuration, forming an inter-seal annulus that can be pressure tested to confirm seal integrity before any intervention. The inline isolation tool is fully certified by DNV and meets the requirements outlined in DBV-OS-F101, DNV-RP-F113 and ASME BPVC Section VIII, Division 2, ensuring compliance with the highest industry standards. 

Prior to mobilisation, a comprehensive Factory Acceptance Test (FAT) was carried out on all 56" equipment at STATS' Abu Dhabi facility. The test replicated site conditions and validated equipment performance under maximum isolation pressure. To further ensure integrity, an additional leak test was conducted at the STATS' Dammam facility before final deployment. Both test phases were witnessed by client representatives, ensuring full alignment to stringent operational and safety standards.

Following thorough pre-deployment inspections, the deployment tray was accurately positioned in front of the pipeline receiver door. The client then depressurised the trap, enabling safe loading of the 56" Tethered Tecno Plug. Using stem bars, the plug was advanced into the receiver until the Door Plug was located in the minor barrel. Once in position, the Door Plug was hydraulically activated, engaging its locks and dual seals to establish the primary isolation and effectively replacing the scraper door. After confirming the double block isolation, the 56" scraper trap valve was opened, allowing the Tecno Plug to be deployed downstream of the valve location.

The Tecno Plug was hydraulically activated at the set position, engaging its lock and dual seals sealing against the internal pipe wall. With the Tecno Plug double block isolation verified, the client de-torqued the existing scraper trap valve. The stem bar was then hydraulically disconnected, allowing removal of the old valve. During this operation, a remote monitoring module maintained continuous surveillance of the plug to the STATS technician. Communication was facilitated using an extremely low-frequency (ELF) inductive system and a manual stab, ensuring full monitoring throughout the isolation phase. The Tecno Plug and Door Plug remained stable under monitored conditions throughout the remedial works, effectively isolating downstream pressure.

Following installation of the new 56” scraper trap valve, the stem bar was reconnected hydraulically and the valve fully torqued. Communication systems were verified, and a flange joint leak test was conducted. Upon successful testing, the Tecno Plug isolation certificate was withdrawn, and Pipeline product was reintroduced into the section between the Tecno Plug and the Door Plug to equalize pressure and prepare for the plug removal sequence. The Tecno Plug was then unset and retracted to its initial deployment position. After closing the new scraper valve, a pressure build-up test was performed to confirm valve integrity. Subsequently, the Tecno Plug was fully retrieved.

Finally, the Door Plug was unset and both the Tecno Plug and Door Plug were retracted to the original deployment tray, marking the successful completion of the operation.