Abstract: A damper cup houses a pulsation damper of a fuel pump such that the damper cup defines a fuel volume together with a fuel pump housing of the fuel pump. The damper cup includes a sidewall which is annular in shape and which extends along a damper cup axis from a sidewall first end to a sidewall second end. The damper cup also includes an end wall which closes the sidewall second end, wherein the sidewall includes a support shoulder which is transverse to the damper cup axis and which is a segment of an annulus extending uninterrupted about the damper cup axis from a shoulder first end to a shoulder second end such that the shoulder first end and the shoulder second end are separated from each other by a gap which is uninterrupted.

Abstract: Vapor guard systems which prevent vapors from reaching a servomotor from a power source for the servomotor. One embodiment uses a control valve which directs such vapors to a vapor trap filter under conditions where vapor flow may be toward the servomotor, and operates to permit purging of the vapor trap filter when there is flow only away from the servomotor. Another embodiment uses an in-line vapor trap filter and a vapor trap canister, normally used to trap fuel vapors from a vehicle fuel tank, to trap fuel vapors from the power source. Both the in-line vapor trap filter and the canister are purged of adsorber vapors where the power source is operating.