orientation indicator can be permanently fixed to the fitting 50 for example by molding it with the fitting when the tubular body is molded or by gluing it to the fitting alternatively the orientation indicator can be removably fixed to the fitting one advantage of using a removable orientation indicator is that it could be used with a plurality of fittings with the installer removing the orientation indicator from the fitting once installation of a particular drainage system is completed because a spirit level type indicator is relatively inexpensive and can be readily formed with the fitting during the molding process when a spirit level type indicator is used it preferably may be permanently fixed to the fitting permanently fixing the indicator to the fitting also is advantageous in that the orientation of the level indicator relative to the longitudinal axis of the fitting is fixed when a mechanical orientation indicator such as a spirit level is fixedly attached to the fitting the fixed position preferably is such that when the indicator indicates a particular orientation for example a horizontal orientation the axis of the inlet of the fitting has a desired predetermined orientation for example sloping downward at a desired angle of for example 1 u00b0 5 u00b0 for example many building codes require a slope of 0 25 inch vertical drop for each one foot of horizontal run of the drain pipe as an alternative to having a single fixed position of the orientation indicator the orientation indicator could be adjustably variably attachable to the fitting so that the user could change the amount of slope that the.