Does this in tank fuel filter have a check valve to prevent fuel from going back into the gas tank? Most of the ones I've seen do, but it isn't mentioned here.
Per the vendor, yes, it does have a check valve.
What is the period of replacement of this in tank fuel filter?
Per the supplier: It depends on where it is being used, but typically it is once a year.
Is this In-Tank Fuel Filter (part # 05-01031) FAA Approved for use in certified aircraft?
Per the supplier: No, they are not approved.