The TSGRAPH_CUTOFF_AT_MAXMIN general setting (OPSROOT.GENERALSETTINGS) allows you to clip the graph when values are outside the user defined axis range. 

SUPER USERS ONLY.  Use SQLCONSOLE:

To find if the value is set:

Select * FROM GENERALSETTINGS WHERE KEYVALUE = 'TSGRAPH_CUTOFF_AT_MAXMIN'

To set the value to clip the graphs:

INSERT INTO GENERALSETTINGS VALUES ('TSGRAPH_CUTOFF_AT_MAXMIN','1')

When the axes in a 2D graph have user-defined scale and range, the axes are drawn independently of the data values. As a result, the graph may extend beyond the boundaries of the axes. You can mask areas beyond the boundaries of the axes by setting ClipGraph = 1 (On).
This property does not apply to 3D graphs.