A diaphragm pump characterized by: a valve housing configured with inlet openings for fluidically connecting an inlet chamber to a valve chamber, and outlet openings for fluidically connecting the valve chamber to an outlet chamber where the fluid and particulate passes to an output port and from the diaphragm pump; inlet duckbill check valve assemblies (10 in), each configured to be arranged in a respective inlet opening for providing fluid and particulate from the inlet chamber to a sequenced valve chamber; and outlet duckbill check valve assemblies (10 out), each configured to be arranged in a respective outlet opening for providing fluid and particulate from the sequenced valve chamber to the outlet chamber; each inlet duckbill check valve assembly (10 in, t) comprising: a duckbill check valve seat configured with an end having a slit to open to provide the fluid and particulate from the inlet chamber to the valve chamber, and to close to prevent the backflow of the fluid and particulate from the outlet chamber to the valve chamber; and a duckbill check valve support having a base portion configured to be inserted inside the duckbill check valve seat, and having a W-shaped portion configured with an opening to pass the fluid and particulate through the duckbill check valve support to the duckbill check valve seat when providing the fluid and particulate from the inlet chamber to the valve chamber, and also configured to provide support for walls (16a, 16b) of the duckbill check valve seat in response to back pressure caused by the fluid and particulate when preventing the backflow of the fluid and particulate from the outlet chamber to the valve chamber, the W-shaped portion includes two end supporting arms (32a, 32d) and two raised intermediate supporting arms (32b, 32c) configured to form the opening to pass the fluid and particulate through the duckbill check valve support to the duckbill check valve seat and provide support for walls (16a, 16b) of the duckbill check valve seat in response to back pressure caused by the fluid and particulate, including back pressure up to about 5,5 bar (80 PSI). a valve housing configured with inlet openings for fluidically connecting an inlet chamber to a valve chamber, and outlet openings for fluidically connecting the valve chamber to an outlet chamber where the fluid and particulate passes to an output port and from the diaphragm pump; inlet duckbill check valve assemblies (10 in), each configured to be arranged in a respective inlet opening for providing fluid and particulate from the inlet chamber to a sequenced valve chamber; and outlet duckbill check valve assemblies (10 out), each configured to be arranged in a respective outlet opening for providing fluid and particulate from the sequenced valve chamber to the outlet chamber; each inlet duckbill check valve assembly (10 in, t) comprising: a duckbill check valve seat configured with an end having a slit to open to provide the fluid and particulate from the inlet chamber to the valve chamber, and to close to prevent the backflow of the fluid and particulate from the outlet chamber to the valve chamber; and a duckbill check valve support having a base portion configured to be inserted inside the duckbill check valve seat, and having a W-shaped portion configured with an opening to pass the fluid and particulate through the duckbill check valve support to the duckbill check valve seat when providing the fluid and particulate from the inlet chamber to the valve chamber, and also configured to provide support for walls (16a, 16b) of the duckbill check valve seat in response to back pressure caused by the fluid and particulate when preventing the backflow of the fluid and particulate from the outlet chamber to the valve chamber, the W-shaped portion includes two end supporting arms (32a, 32d) and two raised intermediate supporting arms (32b, 32c) configured to form the opening to pass the fluid and particulate through the duckbill check valve support to the duckbill check valve seat and provide support for walls (16a, 16b) of the duckbill check valve seat in response to back pressure caused by the fluid and particulate, including back pressure up to about 5,5 bar (80 PSI). a duckbill check valve seat configured with an end having a slit to open to provide the fluid and particulate from the inlet chamber to the valve chamber, and to close to prevent the backflow of the fluid and particulate from the outlet chamber to the valve chamber; and a duckbill check valve support having a base portion configured to be inserted inside the duckbill check valve seat, and having a W-shaped portion configured with an opening to pass the fluid and particulate through the duckbill check valve support to the duckbill check valve seat when providing the fluid and particulate from the inlet chamber to the valve chamber, and also configured to provide support for walls (16a, 16b) of the duckbill check valve seat in response to back pressure caused by the fluid and particulate when preventing the backflow of the fluid and particulate from the outlet chamber to the valve chamber, the W-shaped portion includes two end supporting arms (32a, 32d) and two raised intermediate supporting arms (32b, 32c) configured to form the opening to pass the fluid and particulate through the duckbill check valve support to the duckbill check valve seat and provide support for walls (16a, 16b) of the duckbill check valve seat in response to back pressure caused by the fluid and particulate, including back pressure up to about 5,5 bar (80 PSI).