Patent ID: 9567737
Date: 2017-02-14
CPC Classifications: E03C,E03D,F16K,Y10T

Claim:
1. A non-return device, the non-return device comprising: a sealing portion having first and second sheet members biased to a sealed position in which the first and second sheet members are at least partially in surface contact; a tubular portion comprising a device inlet, wherein the tubular portion comprises a non-constant tubular length that depends on a circumferential position around the tubular portion, wherein the device inlet is a circular flange defining a circular opening, the circular flange comprising a thickened portion and acting to hold the device inlet open; a device outlet; and a transition portion providing fluid communication between the device inlet, the tubular portion and the sealing portion, the transition portion having a bowed-out convex section of wall for allowing a build-up of fluid within the non-return device in the transition portion in an immediate vicinity of the sealing portion; wherein in use, the device outlet is oriented in a downwards position relative to the device inlet and fluid build-up in at least one of: the tubular portion and the transition portion forces the first and second sheet members apart to an open position; and wherein the non-return device is a waste trap non-return device.