The hammer union pressure transducer engages with a cinch nut of a hammer union coupling to cinch a nose end toward an internal sealing surface of a male component of the hammer union coupling. The transducer includes a connection end removably threaded to the nose end. An anti-rotation device engages the connection end and the nose end, inhibiting inadvertent unthreading. The anti-rotation device is removable or shearable, allowing unthreading of the connection end from the nose end as desired. A recess may be formed on the external sealing surface of the nose end and an insert may be disposed in the recess. The insert, if used, may be formed of a material that is different from a material of the nose end. An upgrade kit may also be employed and includes an adapter plate to connect to the nose end.