Insulation flanges are not essentially different from ordinary flange connections in appearance. It is just that the gasket between the two flanges is made of insulating material; each bolt, nut and flange are insulated from each other by a stepped insulating sleeve. The axial tensile load that this structure can withstand is limited by the step strength of the plastic sleeve and cannot be very high.
The axial compression force that can withstand is limited by the elastic limit of the (seal) insulating gasket. Excessive axial compression force will cause it to lose its elasticity and damage the sealing performance; One side tends to reduce the sealability, while the other side may lose its elasticity due to excessive force. Its hermetic insulation is directly exposed and in direct contact with moist gas or soil, and its necessary insulation performance is reduced.