In service refractories lined in RH snorkels are frequently exposed to high temperatures and suffer severe thermomechanical loads. Under such conditions creep may also play a role in the joint opening of the working lining. To investigate the impact of creep on the thermomechanical behaviour of RH snorkels, classical and Drucker-Prager creep models could be applicable. The first one is often used to describe the mere creep behaviour of materials whilst the second one considers both shear failure and creep as hydrostatic pressure dependent. A RH snorkel comprising magnesia chromite brick lining was studied including the operation procedure of preheating, submerging and idle time. Two specific testing approaches viz. modified shear test and creep test were employed to gain the input parameters for the modeling. Significantly different results out of the two creep models quoted above were observed in terms of the creep strain and the stress distribution. It indicates that further investigation of creep behaviour of refractories under service related loading conditions is necessary.