Altarpiece two, three, and multiple panels respectively. In the thirteenth century each panel was usually surmounted with a pinnacle, but during the Renaissance, single panel, or "pala", altarpieces became the norm. In both cases the supporting plinth, or "predella" often featured supplementary and related paintings. If the altar stands free in the choir, both sides of the altarpiece can be covered with painting. The screen, retable or reredos are commonly decorated. Groups of statuary can also be placed "on" an altar. A single church can furthermore house several altarpieces on side-altars in chapels. Sometimes the altarpiece is set on the altar
Hinged expansion joint joints used in piping systems are restricted to pure angular rotation by its hinges. As a pair, hinged expansion joints will function together to absorb lateral deflection. Advantages of hinged expansion joints are that they are typically compact in size and structurally rigid. Hinged expansion joint A hinged expansion joint is a metallic assembly, that can rotate in a single plane, used to absorb changes resulting from piping thermal expansion or contraction. They include hinges, attached to the expansion joint ends with a pair of pins, which allow angular movement in a single plane, restrain the pressure thrust, and prevent