Control valve filter and control valve insertion structure

A control valve filter that is attached to a peripheral groove formed on an external peripheral surface of a control valve and that is configured to filter a fluid flowing into or out of a port unit that is opened through the peripheral groove, the control valve filter comprising:

• a substantially ring-shaped frame;
• and
• a filter member provided on the frame, wherein
• the frame includes a divided portion formed at a peripheral portion of the frame,
• the divided portion includes a first engagement unit and a second engagement unit configured to engage with the first engagement unit,
• the first engagement unit has a recessed portion,
• the second engagement unit has a projection portion configured to engage with the recessed portion,
• a width of an opening portion of the recessed portion is narrower than a width at a deeper side of the recessed portion, and
• when the first engagement unit is engaged with the second engagement unit, the projection portion is engaged with the recessed portion in a diameter direction of the frame.