Abstract: A multiline check valve assembly has an elongated body which defines a fluid passageway and which is formed with a plurality of valve cavities that are in fluid communication with the fluid passageway. Each valve cavity has a resilient valve element disposed within the cavity and each valve element rests in the cavity with one end against a protrusion disposed in the cavity for centering the element within the cavity. The resilient valve element is biased to urge its other end against a valve seat that surrounds an opening to the valve cavity to create a fluid tight seal with the valve seat and close the opening. In addition, an access port is formed circumferentially around both the valve seat and opening to establish a fluid communication path through the access port to the fluid passageway in the body when the valve element is separated from the valve seat.