The ornamental design for a valvehousing, as shown and described.
1. Valve housing
1.1 : Front
1.2 : Perspective
1.3 : Perspective
1.4 : Right
1.5 : Top
1.6 : Bottom
Figure 1.1: front view; figure 1.2: right side perspective view; figure 1.3: left side perspective view; figure 1.4: right side view; figure 1.5: top view; figure 1.6 bottom view.