Double flap non-return valve - has adjustable flap stop also allowing flaps to be locked in valve closed position

摘要

The double flap non-return valve has two D-shaped flaps provided with lugs on the upper surfaces. The lugs enable a pair of flaps to be mounted on a common hinge pin which passes through diametrically opposite holes in the valve body. The hinge pin consists of three parts. A central tube with an integral thread and two rods which are screwed into each end. Each rod carries a transverse pin which passes through a slot in the lug. The pin acts as a stop to the valve flap and by rotating the hinge pin the position of the stop can be adjusted.