Hansen Relief Valves

relief valves
(Relief valve) A device designed to open if it detects excess temperature or pressure.
The relief valve (RV) is a type of valve used to control or limit the pressure in a system or vessel which can build up by a process upset, instrument or equipment failure, or fire.
(relief valve) safety valve: a valve in a container in which pressure can build up (as a steam boiler); it opens automatically when the pressure reaches a dangerous level

hansen
Hansen is a lunar impact crater that is located near the eastern limb of the Moon. At this location the crater appears oval due to foreshortening, but the crater is actually nearly circular. It lies to the northeast of the larger crater Condorcet, and to the south of the smaller Alhazen.
The Siberian Elm Ulmus pumila cultivar 'Hansen' is a little-known tree of obscure origin, other than that it was almost certainly raised in the USA.Santamour, F. S., & Bentz, S. E. Updated checklist of elm (Ulmus) cultivars for use in North America. Journal of Arboriculture, 21(3): May, 1995. .
Hansen is a Danish-Norwegian patronymic surname, literally meaning son of Hans. It is the third most common surname in Denmark, shared by about 4.3% of the population .