A sanitary valve system (10) comprising an actuator arrangement (20) in an actuator housing (32) comprising a first piston chamber (30I) with a first piston (32I) separating the first piston chamber in a first upper cavity (341U) and a first lower cavity (341L) and having a first piston shaft (36I) configured to operate outside of the actuator housing. The valve system is configured to operate in multiple states. The operation of each state and transitions amongst states including identical states are controlled by regulating the liquid pressure or flow in each respective first and second upper and lower cavities. The regulation of liquid may be via a common distribution plate arrangement (90). The distribution arrangement may be with least one common distribution plate (92) with a set of canals (94) configured to connect at least one set of upper and lower regulation lines (82IU, 82IL,82IIU, 82IIL) with the respective first and second upper and communication lines (50IU, 50IL, 50IIU, 50I IL). A sanitary valve kit and a method of retrofitting an existing valve arrangement are also disclosed.

Aspects of the present disclosure relate to fail open or fail close actuator assemblies and related methods for valve systems. In one implementation, an actuator assembly for valves includes an outer housing that includes an inner surface at least partially defining an internal volume. The actuator assembly includes one or more first fluid openings formed in the outer housing, one or more second fluid openings formed in the outer housing, and one or more ambient openings formed in the outer housing. The actuator assembly includes a valve stem disposed at least partially in the internal volume, and a first piston disposed in the internal volume and coupled to the valve stem. The actuator assembly includes a second piston disposed in the internal volume and disposed about the valve stem.

A modular electrohydraulic actuator including an electric motor, a hydraulic pump driven by the electric motor, and a hydraulic actuator in fluid communication with the hydraulic pump. The hydraulic actuator includes a hydraulic cylinder supporting a pressure sleeve in which a piston and rod is adapted for reciprocating motion in response to a supply of pressurized fluid to a first side or a second side of the piston, wherein at least one of the electric motor, hydraulic pump, hydraulic cylinder, piston, piston rod or the pressure sleeve supported in the hydraulic cylinder is selectively removable and replaceable with a different component to vary at least one performance characteristic of the electrohydraulic actuator.

A hydraulic cylinder comprising a cylinder, a piston element movably guided in the cylinder in a working direction and comprising an active surface, and a first opening for feeding a fluid into a cylinder chamber by the active surface. A working pressure of the fluid acting on the active surface drives the piston element in the working direction. The active surface includes a first partial surface and at least one second partial surface, the cylinder chamber being divided into a first sub chamber with the first opening by the first active surface and a second partial surface with a second opening by the second partial surface, and the partial surfaces are hydraulically separated from each other at least in a selectable operating mode.

An assembly for hoisting and lowering a drill string of a drilling rig includes a multiple displacement hydraulic cylinder having a blind end, a rod end, and a single piston rod configured for slidable extension and retraction movement within the interior space of the cylinder. The interior space is defined by three chambers, each chamber having a port allowing switchable flow of hydraulic fluid into and out from the cylinder. The assembly also includes a pumping and switching system with hydraulic fluid connections to each port of the cylinder. The pumping and switching system is configured to switch the direction of hydraulic fluid flow through each of the ports of the three chambers, thereby providing the assembly with a plurality of hydraulic fluid flow path combinations. Each flow path combination provides a different speed-to-force ratio for extending or retracting the piston rod, thereby hoisting or lowering the drill string.

An assembly for hoisting and lowering a drill string of a drilling rig includes a multiple displacement hydraulic cylinder having a blind end, a rod end, and a single piston rod configured for slidable extension and retraction movement within the interior space of the cylinder. The interior space is defined by three chambers, each chamber having a port allowing switchable flow of hydraulic fluid into and out from the cylinder. The assembly also includes a pumping and switching system with hydraulic fluid connections to each port of the cylinder. The pumping and switching system is configured to switch the direction of hydraulic fluid flow through each of the ports of the three chambers, thereby providing the assembly with a plurality of hydraulic fluid flow path combinations. Each flow path combination provides a different speed-to-force ratio for extending or retracting the piston rod, thereby hoisting or lowering the drill string.

An assembly for hoisting and lowering a drill string of a drilling rig includes a multiple displacement hydraulic cylinder having a blind end, a rod end, and a single piston rod configured for slidable extension and retraction movement within the interior space of the cylinder. The interior space is defined by three chambers, each chamber having a port allowing switchable flow of hydraulic fluid into and out from the cylinder. The assembly also includes a pumping and switching system with hydraulic fluid connections to each port of the cylinder. The pumping and switching system is configured to switch the direction of hydraulic fluid flow through each of the ports of the three chambers, thereby providing the assembly with a plurality of hydraulic fluid flow path combinations. Each flow path combination provides a different speed-to-force ratio for extending or retracting the piston rod, thereby hoisting or lowering the drill string.

An assembly for hoisting and lowering a drill string of a drilling rig includes a multiple displacement hydraulic cylinder having a blind end, a rod end, and a single piston rod configured for slidable extension and retraction movement within the interior space of the cylinder. The interior space is defined by three chambers, each chamber having a port allowing switchable flow of hydraulic fluid into and out from the cylinder. The assembly also includes a pumping and switching system with hydraulic fluid connections to each port of the cylinder. The pumping and switching system is configured to switch the direction of hydraulic fluid flow through each of the ports of the three chambers, thereby providing the assembly with a plurality of hydraulic fluid flow path combinations. Each flow path combination provides a different speed-to-force ratio for extending or retracting the piston rod, thereby hoisting or lowering the drill string.

Disclosed is a piston-cylinder assembly of a hydraulic press, which includes a basic cylinder and a first and second piston. A ring cylinder is formed above the basic cylinder as a continuation of the cylinder structure. The first piston is located inside the basic cylinder in the bottom part of the basic cylinder and the second piston is located above the first piston in the top part of the cylinder structure. The piston-cylinder assembly has a first hydraulic fluid space below the first piston and a second hydraulic fluid space below the second piston and the piston-cylinder assembly includes a unified hydraulic fluid channel in flow connection to the first hydraulic fluid space in order to provide a pressure effect in the first piston and to the second hydraulic fluid space in order to provide a pressure effect in the second piston.

A hydraulic system includes a first hydraulic actuator, a second hydraulic actuator, a first pump to supply operation fluid to the first hydraulic actuator, a second pump to supply operation fluid to the second hydraulic actuator, a second control valve to control operation fluid to be supplied from the second pump to the second hydraulic actuator, and a first control valve including a main control valve to control operation fluid to be supplied from the first pump to the first hydraulic actuator, and a subordinate control valve configured to control operation fluid to be supplied from the second pump to the second control valve and to the first hydraulic actuator. The operation fluid supplied from the second pump is confluent with operation fluid to be supplied from the first pump to the first pump, in a case of activating both of the first hydraulic actuator and the second hydraulic actuator.