Abstract: An actuator for operating a valve comprises a housing, a cap, a ring and a piston. The housing has a connecting interface for being mounted on the valve. The cap substantially covers a first portion of the housing. Both the cap and the housing define a substantially enclosed space inside the housing. The ring sealably covers a second portion of the housing. The ring is equipped with two ports that are in fluid communication with the enclosed space. The piston is slidably located inside the housing. Advantageously, an actuator assembly may include the actuator as previously described and one bonnet, one of the connecting interfaces of the actuator being connected to the bonnet. The bonnet is adapted to be mounted to a valve body.

Abstract: An actuator for operating a valve comprises a housing, a cap, a ring and a piston. The housing has a connecting interface for being mounted on the valve. The cap substantially covers a first portion of the housing. Both the cap and the housing define a substantially enclosed space inside the housing. The ring sealably covers a second portion of the housing. The ring is equipped with two ports that are in fluid communication with the enclosed space. The piston is slidably located inside the housing. Advantageously, an actuator assembly may include the actuator as previously described and one bonnet, one of the connecting interfaces of the actuator being connected to the bonnet. The bonnet is adapted to be mounted to a valve body.