Hull Maintenance Technicians — HTs — were the Navy’s shipboard pipe fitters, welders, and damage control specialists, responsible for maintaining the ship’s hull integrity, piping systems, valves, and damage control equipment throughout the fleet. HTs replaced and repaired steam piping, installed and overhauled valves, maintained damage control flooding boundaries, and operated the ship’s emergency repair capabilities during damage control evolutions. The HT rating’s direct hands-on work with steam system piping and valve components placed these personnel in the highest-contact position with asbestos-containing materials in the ship’s piping and valve systems.

Pipe System Work and Asbestos

HTs performed pipe installation and repair work that involved the most direct contact with asbestos insulation materials of any rating:

  • Steam pipe insulation removal and installation — HTs performing steam pipe repair were required to remove asbestos pipe covering from the pipe section to be worked, perform the repair weld or fitting replacement, and reinstall new asbestos pipe covering over the repaired section. Removing asbestos pipe covering — cutting, peeling, and disposing of the old insulation — released asbestos fiber in immediate proximity to the HT performing the work. This cycle repeated throughout each HT’s shipboard career as pipes were repaired and sections replaced
  • Pipe flange gasket replacement — HT pipe fitting work involved replacing gaskets at flanged pipe connections throughout the ship’s piping systems. Breaking a steam pipe flange joint, scraping the old asbestos gasket material from the flange faces, and installing a new gasket cut from asbestos gasket sheet released asbestos fiber during the scraping and cutting operations
  • Pipe threading and fabrication — HTs fabricating new pipe sections in the ship’s pipe shop cut and threaded pipe using the ship’s pipe threading equipment, with asbestos tape used as thread compound and sealing material in some steam service applications

Valve Packing and Repair

HT valve maintenance work involved asbestos packing throughout the valve inventory:

  • Valve stem packing replacement — stuffing box repacking on gate valves, globe valves, and other steam service valves was HT work, involving removal of old asbestos packing from the stuffing box, cleaning the stuffing box, and installing new asbestos packing rings. This maintenance task was performed continuously throughout the fleet’s valve inventory
  • Valve bonnet gasket replacement — HTs performing valve bonnet removal for internal valve inspection and seat maintenance disturbed asbestos bonnet gaskets at every bonnet removal

Damage Control Equipment Maintenance

HT damage control responsibilities included maintaining equipment that itself contained asbestos:

  • Damage control locker equipment — asbestos damage control suit components — asbestos mittens, asbestos suit liners — were maintained and stowed by HTs in damage control lockers throughout the ship
  • Fire station hose fittings and nozzles — brass fire hose fittings and nozzle gaskets maintained by HTs in fire station upkeep

VA Claims for HT Veterans

VA presumptive service connection under 38 CFR § 3.309(d) covers asbestos exposure from pipe fitting and damage control maintenance in Navy service. Hull Maintenance Technicians and their predecessor ratings (Damage Controlman, Shipfitter) who served in HT billets aboard surface ships built before the mid-1970s asbestos phase-down and have since been diagnosed with mesothelioma, asbestosis, or asbestos-related lung cancer may qualify for VA disability benefits. HTs represent one of the highest direct-contact asbestos exposure ratings in the Navy due to their pipe insulation removal and installation work.