Abstract: A two-stage membrane pump having a first pump head and a second pump head is provided. The pump heads are typically crank operated with a camshaft set up such that one pump head is in exhaust mode and the other in inlet mode, and vice-versa, during operation. The membrane and the inlet and outlet valves of the pump heads are designed to work together, along with each pump head working synchronously such that the inlet of the second pump head and exhaust of the first pump head are sealed by the actions of the two membranes. As a result an inlet valve in the second pump head is not needed. The costs of such a pump are thereby reduced while increasing the reliability of the two-stage pump.

Abstract: A valve pin insert has a body for insertion into a valve plate and a stud integrally formed with the body and extending from one end of the body above the valve plate. The body has a lower shank at an end of the body that is opposite from the end at which the stud is positioned, and an upper shank at the end of the body adjacent to the end of the body at which the stud is positioned. The lower shank is of a lesser diameter than the upper shank and an undercut shoulder between the shanks forms a recess opening in the direction toward the lower shank and forms a tooth which shears material of the valve plate as the pin is inserted into a hole in the valve plate.

Abstract: A two-stage membrane pump having a first pump head and a second pump head is provided. The pump heads are typically crank operated with a camshaft set up such that one pump head is in exhaust mode and the other in inlet mode, and vice-versa, during operation. The membrane and the inlet and outlet valves of the pump heads are designed to work together, along with each pump head working synchronously such that the inlet of the second pump head and exhaust of the first pump head are sealed by the actions of the two membranes. As a result an inlet valve in the second pump head is not needed. The costs of such a pump are thereby reduced while increasing the reliability of the two-stage pump.

Abstract: A nutating pump has a cross-type universal joint connecting a nutating member to a pump housing, ball joints connecting the nutating member to piston rods, and the piston rods fixed to piston heads so that the piston heads wobble in pump cylinders.

Abstract: A valve pin insert has a body for insertion into a valve plate and a stud integrally formed with the body and extending from one end of the body above the valve plate. The body has a lower shank at an end of the body that is opposite from the end at which the stud is positioned, and an upper shank at the end of the body adjacent to the end of the body at which the stud is positioned. The lower shank is of a lesser diameter than the upper shank and an undercut shoulder between the shanks forms a recess opening in the direction toward the lower shank and forms a tooth which shears material of the valve plate as the pin is inserted into a hole in the valve plate. The insert is a relatively harder plastic and the valve plate is a relatively softer plastic.

Abstract: A fitting for coupling a pump attachment to the inlet or discharge port of a pump or compressor has an annular body with an externally threaded nipple at one end and a circular flange at the other end. An axial aperture extends between the ends through openings at the nipple and the flange. The opening at the flange is internally threaded and begins at a recess in the flange. The threaded opening is of a standard ISO rated size complementary to the threaded nipple. A coupler kit is also disclosed having components to connect the device to the pump either in a mating flange connection using a hinge clamp or a threaded connection using a hose barb having a threaded end that threads into the opening in the fitting.

Abstract: A fitting for coupling a pump attachment to the inlet or discharge port of a pump or compressor has an annular body with an externally threaded nipple at one end and a circular flange at the other end. An axial aperture extends between the ends through openings at the nipple and the flange. The opening at the flange is internally threaded and begins at a recess in the flange. The threaded opening is of a standard ISO rated size complementary to the threaded nipple. A coupler kit is also disclosed having components to connect the device to the pump either in a mating flange connection using a hinge clamp or a threaded connection using a hose barb having a threaded end that threads into the opening in the fitting.

Abstract: A chemical vapor trap for selectively removing harmful corrosive contaminants, such as water and acetic acid vapors, from an evacuating vapor phase in a vacuum drying system is provided. The chemical vapor trap includes a condenser section effective to convert a high temperature incoming heated sample liquids and heated vapor phase into a liquid phase condensate and a relatively lower room temperature stripped vapor phase. Liquid condensate including water and acetic acid are trapped below a chemical blanket or sealing layer which prevents re-vaporization or boiling of removed corrosive volatile contaminants from the vapor phase entering the vacuum pumps, promoting improved pump performance and extend pump service life.