Methods and apparatus to access and align sealing discs are disclosed herein. An example apparatus includes a cage of a fluid regulator, where the cage has a central aperture, and a valve stem to be received by the central aperture. The example apparatus also includes a diaphragm coupled to the valve stem, where an integral protrusion of the cage is to constrain a peripheral edge of the diaphragm against a removable portion of a valve body when the cage is coupled to the valve body.

A method and arrangement for maintaining fluid flow pressure in a system at a preset, almost constant level. One application is an impulse turbine's nozzle valve, which automatically maintains the system pressure essentially constant so that it does not depend on occasional variation of the pumped inflow, resulting that also the jet from the nozzle remains constant and its kinetic energy optimal. The nozzles independently maintain system pressure when the inflow varies.

A fluid regulating device includes a regulator valve having an inlet, an outlet, and a valve port disposed between the inlet and the outlet. An actuator is coupled to the regulator valve and includes a valve disc that displaces between a closed position and an open position. The device also includes an overpressure protection device adapted to stop flow from the inlet to the outlet when pressure in a control cavity reaches a predetermined level. The overpressure protection device includes a sensing tube having a first end in fluid communication with the control cavity and a second end in fluid communication with the outlet. The sensing tube has a first portion extending parallel to the flow axis. One or more apertures are disposed in the sensing tube adjacent to the second end, and each of the apertures has a centerline that is perpendicular to the flow axis.

A channel block for a liquid chemical dosing apparatus. The channel block has a process outlet; a chemical liquid inlet; an evacuation outlet; a calibration column outlet; channels provided within the channel block that connect at least the process outlet, the chemical liquid inlet, the evacuation outlet and the calibration column outlet; a pressure indicator mounted to the channel block to measure the pressure of the chemical liquid entering through the chemical liquid inlet; a additional regulation valve mounted to the channel block upstream of at least one of the process outlet and the calibration column outlet; a evacuation regulation valve mounted to the channel block upstream of the evacuation outlet; at least three control valves mounted to the block configured to control the chemical liquid passing through the channels.

A gas negative pressure valve is provided which comprises a valve body and a valve cover. A gas inlet and a gas outlet are disposed on the valve body. A drive lever and a diaphragm assembly are disposed inside the valve body, and one end of the drive lever is connected to a lower end of the diaphragm assembly, and the other end of the drive lever is connected with a sealing gasket. An end of the drive lever is hinged on a sidewall of the valve body. A reset spring is disposed between the drive lever and a bottom of an inner chamber of the valve body. A guide passage is opened in the inner chamber of the valve body. An end of the drive lever close to the gas inlet is connected with a guide shaft, a lower end of which is cooperated slidably in the guide passage.

Example embodiments relate to a gas-pressure regulator having an inlet, an outlet, a housing, a diaphragm, a control element, a control chamber and a discharge chamber. The inlet and the outlet each open onto the control chamber, wherein the diaphragm partially delimits the control chamber. The diaphragm and the control element are movable relative to each other, wherein a passage between the control chamber and the discharge chamber is open in a relative discharge arrangement of the diaphragm and the control element. An adjustable biasing element impedes a relative movement between the diaphragm and the control element.