A compressor includes a cylinder block having a first bore and a cylinder head overlapping the cylinder block. The cylinder head has a second bore aligned with the first bore. The second bore is separated into a plurality of distinct regions including a suction region and an economizer region. A plurality of valves includes a suction valve selectively operable to fluidly couple the suction region and the first bore, and an economizer valve selectively operable to fluidly couple the economizer region and the first bore.

A method of controlling an actuation pump including monitoring a supply pressure of a pump, monitoring an outlet pressure of the pump, commanding a motor by a motor controller, which receives the monitored pressures, to drive the pump at a speed based on a comparison of the supply pressure and the outlet pressure of the pump.

A method for determining a flow volume of a fluid delivered by a pump. The flow volume is determined as a function of predefined pump information depending on a pump geometry, rotation speed information, which correlates with the rotation speed of the pump, and pressure information, which correlates with a differential pressure at the pump.

Apparatus, including a pump system controller, features a signal processor or processing module configured at least to: receive signaling containing information about pump differential pressure, flow rate and corresponding power data at motor maximum speed published by pump manufacturers, as well as instant motor power and speed, for a system of pumps arranged in a multiple pump configuration; and determine corresponding signaling containing information about instant pump differential pressure and flow rate for the system of pumps arranged in the multiple pump configuration using a combined affinity equation and numerical interpolation algorithm, based upon the signaling received.

A hydraulic fluid control system for a hydraulic diaphragm pump including at least one hydraulic diaphragm containing a process fluid surrounded by at least one hydraulic fluid chamber containing a hydraulic fluid is provided. The system includes a differential pressure sensor operable to detect and measure a pressure difference between the process fluid contained in the at least one hydraulic diaphragm and the hydraulic fluid contained in the at least one hydraulic fluid chamber; a hydraulic fluid reservoir containing hydraulic fluid; and a hydraulic fluid pump fluidly connected to the hydraulic fluid reservoir and the at least one hydraulic fluid chamber, and operable to provide a volume of hydraulic fluid to the at least one hydraulic fluid chamber in response to the pressure difference measured by the differential pressure sensor. The system is optionally operable to withdraw a volume of hydraulic fluid from the hydraulic fluid chamber.

A pump controller features a signal processor configured to respond to signaling containing information about three corresponding discrete arrays with respect to a discrete motor speed for each system position at a motor speed derived from 3D discrete distribution surfaces of motor power, pump differential pressure and flow rate by respective numerical interpolations; and determine corresponding signaling containing information to control a pump, or pumps in a system of pumps, or a system of pumps based upon a corresponding pump differential pressure and flow rate at the motor speed for a corresponding power reading value determined using a numerical interpolation of the three corresponding discrete arrays, the signaling received. The signal processor is configured to provide the corresponding signaling as control signaling to control the pump, or the pumps in the system of pumps, or the system of pumps.

The invention relates to a method for monitoring and controlling the operation of a pump station (1) comprising a tank (8) for storage of a liquid and at least one pump (2), the pump station (1) further comprises an outlet conduit (5) connected to the pump (2), the method comprising the steps of: determining the Geodetic head (Hgeo) of the pump station (1), determining the pumped

Flow (Q) for a given pump operation duty point, determining the consumed Power (P) for the given pump operation duty point, and determining a Normalized Specific Energy (nSE) of the pump station (1) based on the determined values of Geodetic head (Hgeo), pumped Flow (Q) and consumed Power (P), by means of the formula (nSE)=(P/Q)/Hgeo.

A system (16) for pumping a fluid, comprising: a pump (17) comprising a suction side (18) and a discharge side (19); a motor (20) for driving the pump, which motor is drivingly connected to the pump via a shaft (21); a return line (23) providing a feed-back conduit for the fluid from the discharge side to the suction side; a control valve (24) controlling the flow of the fluid through the return line; and a first sensor device (27) for monitoring a first system parameter which is a function of the differential pressure across the pump. The system further comprises: a second sensor device (28) for monitoring a second system parameter which is a function of the torque of the pump; and a control unit (25) arranged to: receive monitored first system parameter values from the first sensor device and, for each monitored first system parameter value, identify a minimum allowable second system parameter value; receive monitored second system parameter values from the second sensor device and, for each monitored second system parameter value, compare the monitored second system parameter value with the identified minimum allowable second parameter value; and regulate the control valve such that the monitored second parameter value does not fall below the minimum allowable second parameter value. A method of operating such a system is also disclosed.

A method for correcting pump model includes: obtaining a pump model for a pump, the pump model including a Q-P curve and a Q-H curve at each of a plurality of frequencies; at each frequency, determining a power error based on a zero-flow-rate power or an actual operating point of the pump under one of the frequencies; and determining a corrected pump model based on the pump model and the power error. The determination of the corrected pump model includes: at each frequency, determining a corrected Q-P curve to be the Q-P curve shifted by the power error; determining a Q-H-P surface based on the corrected Q-P curves and the Q-H curves at all the frequencies; at each frequency, determining a head error based on the surface and the power error; and at each frequency, determining a corrected Q-H curve to be the Q-H curve shifted by the head error.

The invention relates to a medical treatment apparatus comprising a tube set 20, a peristaltic pump 6 for conveying fluid, and a monitoring apparatus 15 for monitoring the occlusion of the positive displacement elements 13A, 13B of the peristaltic pump. In addition, the invention relates to a tube set 20 for a medical treatment apparatus, and to a method for monitoring the occlusion of the occlusion elements of a peristaltic pump for conveying a fluid for a medical treatment apparatus. The invention is based on the fact that the occlusion of the positive displacement elements 13A, 13B of the peristaltic pump 6 is monitored in order to monitor the fluid flow in the hose line 5. For this purpose, the electrical resistance or a variable which correlates with the electrical resistance is measured between a first and a second electrode 16A, 16B, the first electrode 16A being arranged on the hose line 5 upstream of the occlusion elements 12 of the peristaltic pump 6 and the second electrode 16b being arranged on the hose line downstream of the occlusion elements such that an electrical contact is produced between the first and second electrode 16A, 16B and the fluid flowing in the hose line 5. The electrodes 16A, 16B are preferably integral component parts of a connecting piece 10, by means of which the hose segment 5A to be inserted into the peristaltic pump 6 is fixed in the form of a loop.