Client: AFCEC
Location: Shemya, Alaska
Scope of Work:
- Site preparation and material staging
- Excavation
- Installation of new piping, valves, and appurtenances, mechanical components
- Testing and commissioning
- Backfill, compaction, and grading
Brice Engineering repaired sections of the Waste Heat Loop System at Eareckson Air Station (EAS) on Shemya Island, Alaska. Our scope of work involved site preparation and material staging; excavation; installation of new PP-RCT piping, valves, and appurtenances; installation of steel piping and mechanical components such as circulating pumps; testing and commissioning; backfill, compaction, and grading.
As part of site preparation, Brice set up three designated work areas and staging materials to support the installation of new pipe around and within Buildings 3045, 3049, 3050, 597, 599, 600, 611, and 618. Flagging, barriers, and appropriate signage of site boundaries were placed as needed to prepare for construction. Prior to performing excavation, Brice applied for an AF103 Dig Permit and had all communication, power, water, and sewer utilities in the work areas located, identified, and marked by the Base Operations Support contractor. Along with the BOS contractor, Brice used a Ground Penetrating Radar machine to verify the accuracy of the locates and ensure there were no unexpected utilities present in excavation areas.
After utility locates were completed and properly marked with surveying paint, Brice excavated adjacent to the existing pipe such that the new NUPI pipe to be installed had sufficient depth of cover per the approved design. The existing pipe was abandoned in place whenever possible and appropriate. When necessary to facilitate the installation of new pipe, the existing pipe was cut out and the abandoned sections were plugged with grout. Once each excavation was completed, Brice installed new supply and return lines using NUPI pipe in accordance with the approved design. New pipe was placed on 6-inches of bedding sand and was hydrostatically pressure tested in accordance with Designer of Record (DOR) and manufacturer recommendations. After each new line was pressure tested, electrofusion joints were sealed using a multi-part wrapping system. Any gaps present at electrofusion joints were filled with Viscopaste, and then each joint was wrapped with Viscotape and 10-mil PVC tape. After joints were wrapped, each ditch was backfilled with sand and compacted to 6-inches above top of pipe. Tracer wire was placed on the compacted sand, the ditch was backfilled with native material and compacted in lifts, warning tape was placed, and the area was graded back to prework elevations.
Interior piping installed to allow for heat loop system connection to each building was schedule 40 carbon steel. Pipe runs installed inside buildings were ran along walls whenever possible to ensure workable/usable space was not lost. The pipe was installed with pipe brackets, supports, and hangars in accordance with the approved design and DOR direction. New steel pipe installed was insulated with 1.5-inch fiberglass insulation and all valves 2-inches and larger were insulated with removable valve blankets. Building penetrations were made with a concrete coring drill and were sealed with grout, caulk, and/or rubber boots and escutcheons depending on location.
Brice conducted hydrostatic pressure testing on new sections of NUPI PP-RCT pipe in accordance with DOR direction and the manufacturer’s system testing procedures. A Brice QC Manager was present for hydrostatic pressure testing. The project passed the final inspection with three deficiencies noted which were addressed. These tasks include seeding excavation areas in the Middle Loop, installing low point vents at the Building 600 heat loop connection, and installing four (4) pipe clamps on 12-inch NUPI pipe. At project completion, we complete and submitted a DD Form 1354 to transfer the system to the government.