Emerson Process Mgmt Regulator Tech (Emerson) is recalling certain Fisher Pressure Relief Valves model numbers H732A, H832A, H733, and H833 manufactured from April 9, 2013, through April 24, 2015 and sold as aftermarket or for use as service replacement equipment in cargo tank trailer applications for transporting compressed gases, such as butane or amines. The flow rate of valves with relief setpoints up to 200 psig may be restricted in the event the tank trailer is involved in a crash or other emergency and is exposed to a fire.