The ASME B31.3 2010 edition is used for Caesar II 2013.

Default value of SIF multiplier is 1.0. But when we chose different value as sustained SIF multiplier in CAESAR II 2013, it will use same SIF multiplier value to calculate pure occasional stress (i.e seismic, wind).

Is there any provision given in ASME B31.3 2010 to use sustained SIF multiplier for pure occasional stress ?

The mode of failure for sustained load and occasional load is the same - yielding (collapse). When evaluating the response to occasional load, those occasional stresses are summed with the sustained stress.
It makes sense to use the same stress formula for both sustained and occasional stress.