Inhalation check valve
A item specifically designed to automatically/manually maintain outlet pressure in a divers helmet/breathing apparatus. It is designed for use with breathing gasses.
NSN 6240-00-886-6615
NSN 5985-00-165-1605
NSN 5920-01-222-3629
NSN 6240-00-458-2550
NSN 5855-01-109-6433
NSN 6130-01-191-9567
NSN 6240-00-187-4306
NSN 5990-00-009-3291
NSN 7035-01-026-1171
NSN 5965-00-275-0491
NSN 4140-00-084-3358
NSN 4140-01-253-5697