This is also known as swing type valve. These valves are designed with perfect flat seating for better sealing. With a pressure rating of PN 0.2 these valves are widely used in suction side of pump to avoid flow reversal.
Rigid and sturdy design with minimum loss of head across the valve
Perfectly flat seating surfaces for good sealing
Preventing entry of foreign body to pump through suction pipe
Long service life
Used in suction side of pump to avoid flow reversal from pump to sump with monobloc pumps