Abstract: The present invention provides an improved gate valve system for cutting off a fluid flowing through a pipe. The gate valve system includes a gate valve and at least one member. The gate valve includes a seal member exhibiting an elastically deformable property for sealingly contacting the inner surface of the pipe, and a support member for receiving said seal member and movable in the perpendicular direction to the flowing direction of the fluid between the outside and inside of the pipe for timely bringing said seal member into a sealing contact with the inner surface of the pipe. The at least one expansion member is deformable, but is not substantially subjected to the volume variation even under pressure. The at least one expansion member is embedded in the seal member in such a manner as to expand the seal member laterally outwardly to the inner surface of the pipe upon receiving pressure effected by the sealing contact between the seal member and the inner surface of the pipe.

Abstract: An exhaustion degree measuring board for measuring the fatigue of photographic processing solutions including a base member having at least one reference density window formed therein along with graduated scales corresponding to a control strip. The reference density windows have upper and lower portions with the upper portion being transparent for viewing the relevant part of the control strip and the lower part of at least one of the windows having a varying dot density. A center line with a reference mark is formed on the base for alignment with the control strip.