A metering diaphragm pump includes a metering chamber, a working chamber and a metering membrane. The metering chamber and the working chamber are separated from one another by the metering membrane. A device for moving the metering membrane back and forth between a first and a second position is provided. The volume of the metering chamber is smaller in a first position than in the second position, and a protective membrane is disposed next to the metering membrane on the working chamber side.

A pump arrangement for powering a pump in providing a controlled volume of water to a drip nozzle in a drip-feed humidifier. The pump arrangement includes: a pump having a solenoid; a processing unit; and a power supply electrically connected to the solenoid via a switch which is controlled by the processing unit. The power supply is structured to supply power to the solenoid via the switch. The processing unit is programmed to modulate the power provided to the solenoid via the switch such that the power is supplied to the solenoid according to a mirror image power profile for each actuation of the solenoid for retracting the armature. The mirror image power profile includes: an initial portion which decreases at a third overall rate, an intermediate portion which decreases at a second overall rate different than the third overall rate, and a final portion which increases at a first overall rate.

A pump arrangement for powering a pump in providing a controlled volume of water to a drip nozzle in a drip-feed humidifier. The pump arrangement includes: a pump having a solenoid; a processing unit; and a power supply electrically connected to the solenoid via a switch which is controlled by the processing unit. The power supply is structured to supply power to the solenoid via the switch. The processing unit is programmed to modulate the power provided to the solenoid via the switch such that the power is supplied to the solenoid according to a mirror image power profile for each actuation of the solenoid for retracting the armature. The mirror image power profile includes: an initial portion which decreases at a third overall rate, an intermediate portion which decreases at a second overall rate different than the third overall rate, and a final portion which increases at a first overall rate.

The present invention relates to a fluid handling device which can prevent an inclination of a rotary member. The fluid handling device includes: a substrate; a circular first groove disposed on the substrate; a second groove connected to the first groove; a third groove connected to the first groove; a film joined to the substrate so as to cover the first groove, the second groove and the third groove; and a joining area where the film and the bottom of the first groove is joined, the joining area being disposed between a connecting portion of the second groove and a connecting portion of the third groove in the first groove. The surface of the film in the joining area is located closer to the bottom of the first groove than the surface of the film in an area joined to the substrate of the film.

The present invention relates to a fluid handling device which can prevent an inclination of a rotary member. The fluid handling device includes: a substrate; a circular first groove disposed on the substrate; a second groove connected to the first groove; a third groove connected to the first groove; a film joined to the substrate so as to cover the first groove, the second groove and the third groove; and a joining area where the film and the bottom of the first groove is joined, the joining area being disposed between a connecting portion of the second groove and a connecting portion of the third groove in the first groove. The surface of the film in the joining area is located closer to the bottom of the first groove than the surface of the film in an area joined to the substrate of the film.

A pumpable resin system for installation of mine bolts includes a resin injection cylinder comprising a resin chamber and a resin hydraulic cylinder, a catalyst injection cylinder including a catalyst chamber and a catalyst hydraulic cylinder, with the resin hydraulic cylinder synchronized with the catalyst hydraulic cylinder, a hydraulic pump in fluid communication with the resin hydraulic cylinder and the catalyst hydraulic cylinder, a hydraulic reservoir in fluid communication with the hydraulic pump, and a delivery line in fluid communication with the resin injection cylinder and the catalyst injection cylinder. The delivery line is configured to deliver resin and catalyst from the resin injection cylinder and catalyst injection cylinder into a borehole.

A pumpable resin system for installation of mine bolts includes a resin injection cylinder comprising a resin chamber and a resin hydraulic cylinder, a catalyst injection cylinder including a catalyst chamber and a catalyst hydraulic cylinder, with the resin hydraulic cylinder synchronized with the catalyst hydraulic cylinder, a hydraulic pump in fluid communication with the resin hydraulic cylinder and the catalyst hydraulic cylinder, a hydraulic reservoir in fluid communication with the hydraulic pump, and a delivery line in fluid communication with the resin injection cylinder and the catalyst injection cylinder. The delivery line is configured to deliver resin and catalyst from the resin injection cylinder and catalyst injection cylinder into a borehole.

When a pipe pressure of a common discharge pipe during an independent discharge step in which only one reciprocating pump among a plurality of reciprocating pumps discharges a fluid to the common discharge pipe differs from internal pressures in pump chambers of the respective reciprocating pumps at discharge step start point angles, a stroke adjustment mechanism adjusts, on the basis of a pressure difference ΔP therebetween, effective stroke lengths of cross heads connected to plungers of the predetermined reciprocating pumps so that the internal pressures in the pump chambers reach the pipe pressure at the discharge step start point angles.

Disclosed herein are robust disposable alternating tangential flow (ATF) housing and diaphragm pump units and associated methods of manufacturing, testing, wetting, and using the same.

Described is a method for treating water with sodium hydroxide. The method can increase the accuracy of the volume of a stock sodium hydroxide solution that is delivered to the water being treated. The method can include pumping a concentrated aqueous sodium hydroxide stock solution with a diaphragm pumping system that has a two-part diaphragm assembly with a polymeric diaphragm overmolded onto a rigid insert. The polymeric diaphragm can be made of a fully-vulcanized ethylene propylene diene monomer rubber that is injection molded over the rigid insert.