Steel housing for high security risk areas - with welded seams accessible to ultrasonic checks during operation

摘要

Large pipe fittings for high security risk areas, such as gate valve housings for nuclear power stations for pipes of up to 1000mm. dia. are mfd. by hot extrusion of the housing from a steel billet. A through bore is machined and its edges are upset by a three-roller expander so that straight tube ends can be welded on. The welds are thus purely circular and accessible to ultrasonic tests during operation. The mfg. costs are much less than machining a housing out of solid steel.