14 CFR § 25.997

Be accessible for draining and cleaning and must incorporate a screen or element which is easily removable;

Have a sediment trap and drain except that it need not have a drain if the strainer or filter is easily removable for drain purposes;

Be mounted so that its weight is not supported by the connecting lines or by the inlet or outlet connections of the strainer or filter itself, unless adequate strength margins under all loading conditions are provided in the lines and connections; and

Have the capacity (with respect to operating limitations established for the engine) to ensure that engine fuel system functioning is not impaired, with the fuel contaminated to a degree (with respect to particle size and density) that is greater than that established for the engine in Part 33 of this chapter.