Abstract: A precision peristaltic pump is provided which assures that a precisely controlled length of tubing is operated upon by the pump. Recesses are provided on either side of a tube receiving gap for the pump, which recesses have different sizes and/or shapes and fittings are provided on the tubing on either side of a precisely determined length of tubing, which fittings are sized and/or shaped so as to only fit in one of the recesses in only a single orientation. This assures that the orientation of the tubing in the pump gap is always the same. The fittings may be a block which is formed on the tubing itself and of the same material as the tubing or may include a stop of a harder material, such as a hard plastic, mounted to or sandwiching each block. The pump is designed so that if one of the fittings is not fully seated in the corresponding recess, the projecting fitting interacts with a cover or other element of the pump to prevent the pump from being moved to its operative position.

Abstract: Suction muffler assembly for hermetic compressors of the type including a cylinder block (4) mounted in the upper part of a hermetic case (3) and provided with a cylinder (10) lodging a reciprocating piston (15); a valve plate (11) attached to an open end of the cylinder (10) and having a suction orifice (11a); a suction muffler assembly attached to the cylinder block (4) and including a hollow muffler body (100) provided with a gas inlet opening (101, 130a) and a gas outlet opening (121); and a suction duct (140) having one inlet end (141) connected to the gas outlet opening (121) and an opposite outlet end (142) in communication with the suction orifice (11a) of the valve plate (11), said hollow muffler body (100) being formed of a lower part (110), presenting an end peripheral edge (117), and a cover upper part (120) carrying the gas outlet opening (121) of the muffler body (100) and including a peripheral lower seating surface portion (127) to be seated onto the end peripheral edge (117) of the lower part

Abstract: A continuously cycling, low pressure, low head pump utilized for supplying periodic surges of water across an algal turf closely associated with the surface of a body of water, this pump comprising a generally vertically disposed cylinder whose lower end resides below the surface of the body of water and whose upper end is disposed above the surface of the body of water and slightly above the algal turf. An opening is provided adjacent the top of the cylinder, through which water, on occasion, can flow onto the algal turf, and a lightweight, buoyant piston is operatively disposed in the cylinder. A power applying device is utilized for forcing the piston downwardly, such that it moves from a partially submerged, floating position adjacent the upper end of the cylinder, to the lower end of the cylinder.