Marshall Excelsior Thermoplastic Hose - Flexible thermoplastic UL and CGA approved hose. These hoses are rated up to 350 psi working pressure with a 400-pound pull test rating. Each hose comes with two ends and fully crimped brass ferrules. Warning: An excess flow valve will not activate if there is a break or leak downstream of the valve that does not equal or exceeds the closing flow of the valve or if the excess flow valve installed exceeds the flow capacity of the system. 1/4 inch Hose ID. All our Marshall Excelsior hoses are suitable for high or low-pressure applications. 1/2 inch Female Flare Swivel; 3/8 inch MNPT - 40 inch OAL.