According to one aspect, a pump assembly includes a fluid cylinder, the fluid cylinder including a fluid passage, the fluid passage defining a tapered internal shoulder of the fluid cylinder, the tapered internal shoulder defining a first angle. A valve controls flow of fluid through the fluid passage. The valve includes a valve seat, which is disposed in the fluid passage and includes a tapered external shoulder, the tapered external shoulder defining a second angle. In one embodiment, the first tapered external shoulder engages the first tapered internal shoulder to distribute and transfer loading.