Seal-Lok fittings and adapters provide high-integrity sealing for hydrogen and CNG (compressed natural gas) fuel-storage and delivery systems. The fittings consist of a nut, sleeve, O-ring, and fitting body. The fitting body face contains a high durometer O-ring held captive in a precision-machined groove. When the nut is tightened, the O-ring compresses between the body and flat face of the tube flange to form a high-integrity seal.
Seal-Lok with H2 technology is designed for high-pressure hydrogen systems and allows full 360° positioning and sealing at 700 bar/10,000 psi. A seal also prevents O-ring extrusion under extreme high pressure. The fittings come in sizes ranging from ¼ to ¾ in. (6 to 20 mm).
Fittings and adapters with tested O-ring compounds are approved for CNG service up to 350 bar/5,000 psi per ECE R110 and ISO 15500.
Parker Hannifin Corp. 
Fluid Connectors Group, Tube Fittings Div.
704 W. Cumberland St.
Lewisburg, OH 45338