The R-K MDV series modular wet bench dump valve features a compact design that is made to be cemented or welded to the bottom panel of the sink. It is remotely operated with a 3-way (for type 1) or 4-way (for type-2) control valve. Its is used to replace trap doors and air cylinders in rinse tanks, etch modules, etc., with no leakage or alignment problems, for less than the cost of a trap door and its required hardware and installation. Dynamic seal o-rings are teflon encapsulated viton for long life and trouble free operation. Its is designed so that the main component can be removed from the installation for easy maintenance and repairs.