Stop ring and a hydraulic/pneumatic device equipped with a stop ring

A stop ring to be fitted in an annular recess circumferentially formed in a wall surface of a fluid passage of a hydraulic/pneumatic device member in which a valve retainer is provided, said valve retainer comprising:

• a retaining section for retaining a valve member along an axis of said fluid passage;
• and
• a plurality of fixing sections extending from said retaining section radially outwardly and circumferentially spaced apart from each other;
• wherein
• said stop ring is made of an elongated elastic member curved in a plane into a ring shape having a first end and a second end spaced apart from each other in a circumferential direction;
• said first end is bent in the said plane to incline inward with respect to a radial direction from the circumferential direction of said stop ring as a reference and to extend towards said second end;
• and
• in a state where said stop ring has been fitted in said annular recess, said first end is, as viewed from a center of said fluid passage, spaced apart from said second end by a smaller distance than a circumferential width of a radially outer end portion of said fixing section, which engages with said stop ring, or said first end overlaps said second end.