Unidirectional flow limiter

A right angle connection element for connection between a fluid pipe and a user apparatus, comprising:

• a first elongated element having an axis and an elongated internal first cavity disposed substantially along the axis of said first element, having means for connecting said first cavity to said fluid pipe to define a flow path between said first cavity and said fluid pipe, and having a bore passing through said first element and through said first cavity, said bore having an axis which is substantially perpendicular to the axis of said first element;
• a second elongated element housed within said bore and exposed to said first cavity, said second element having an axis and an elongated internal second cavity disposed substantially along the axis of said second element, having a first plurality of apertures disposed radially around said second element to define a plurality of first passage ways extending between said first and second cavities, having a second plurality of apertures disposed radially around said second element to define a plurality of second passage ways extending between said first and second cavities, and having means for connecting said second cavity to said user apparatus to define a flow path between said second cavity and said user apparatus;
• means adjustably mounted within said second cavity of said second element for at least partially closing said plurality of first passage ways;
• and
• unidirectional means for unidirectionally closing said plurality of second passage ways, said unidirectional means including a deformable annular member attached to said second element and covering each of said second plurality of apertures.