A rotary mechanical fluid seal for use in high pressure and/or high temperature environments, comprising a unitary structure adapted to cooperate with a rotating member and consisting of a cup having an inner shell with a shaft opening, a primary sealing ring having a sealing face engageable with a rotating member and slidably mounted in said housing, a secondary sealing element, fabricated from semi-resilient material, slidably engaging said primary sealing ring in fluid tight relationship and slidably engaging the inner shell or shaft in fluid tight relationship.