Typically a valve body consists of 2 or 3 pieces that are bolted together and smaller ones are screwed. However it is also possible to have the body without bolts. The valve body parts are than welded together. With the smaller valves which are screwed it is a sealweld. With larger valves the body parts are welded together. Generally there are 2 construction types: -similar to the bolted type but instead of bolted these parts are welded together -formed body parts which are welded together The advantage of the formed parts is that they have smaller dimensions and are lighter. The overall advantage of the (seal) welded body is that they have less potential leak paths.