One specific type of check valves

The rubber check valve is one of the specific types of check valves. Or it can be further said that rubber check valve is another style of swing check valve. The rubber check valve is also regarded as the rubber flapper valve. As a result, the flapper is the feature of the rubber check valve, as well as the rubber sealing.
The performance of the shut off has been greatly improved comparing that of the conventional swing check valve. The seating arrangement in this valve and the flapper are the keys to its success.
The seat of the rubber check valve is on a 45 degree angle and therefore the flapper travels only 35 degrees to reach full open position. In fact, the area through this style valve is equal to or greater than the equivalent pipe size. This is accomplished by enlargement of the flow area immediately downstream of the flapper.