A valve seat for use in a high pressure pump comprises an inner portion force fit within an outer portion. The outer portion has a fluid plenum at an outer peripheral surface. Fluid passages extend radially inwardly to communicate with a valve recess in the inner portion. A seal housing for a high pressure pump comprises an outer portion and an inner portion. The inner portion is force fit within the outer portion. The inner portion has an inner bore having a first location to receive seal packings, and a second location to receive valve spring structure. The inner portion has a curved surface that bottoms out against a curved surface within the outer portion.