A compact, reliable, and easily manufacture relief valve capable of resolving pressure issues within a fuel cell system and its components or devices. The relief valve comprises a valve body having a first cap, a valve housing and a center post; and an elastomeric member or sealing member contained within the valve body and being secured to the valve body at one end and forming a seal with the valve body at the other end. The seal opens in response to a threshold pressure being exceeded. In one embodiment, the elastomeric member is secured to the interior of the first cap and/or valve housing and forms a seal with the outer diameter of the center post. The elastomeric member may be supported by a reinforcing member.