Pressure Ratings - my-ssp-usa.com Pressure Ratings For Tubing and Threaded End Connections. Generally, SSP tube fittings, adapters and components (fittings) are rated for pressures equal to the maximum allowable working pressures of the tubing, hose or pipe recommended for use with the fittings.Pressure ratings for fittings with both tube fitting and pipe thread ends are determined by the end connection with the lower pressure ...