Abstract: An adsorption gas dryer has a first drying tower and a second drying tower each having a first port and a second port through which gas can pass into or out of the tower, a first manifold and a second manifold connected respectively to the first and the second ports of both towers, the manifolds each including integral gas passages, each port of the towers being in communication with a gas passage, and the manifolds each including at least one integral valve seat upon which a valve actuator is mounted to constitute a valve for controlling flow of gas through the gas passages, wherein the second manifold has two exhaust valves for controlling purge gas.

Abstract: An adsorption gas dryer has a first drying tower and a second drying tower each having a first port and a second port through which gas can pass into or out of the tower, a first manifold and a second manifold connected respectively to the first and the second ports of both towers, the manifolds each including integral gas passages, each port of the towers being in communication with a gas passage, and the manifolds each including at least one integral valve seat upon which a valve actuator is mounted to constitute a valve for controlling flow of gas through the gas passages, wherein the second manifold has two exhaust valves for controlling purge gas.

Abstract: A filter unit comprises a housing through a wall of which is formed an aperture, an annular insert of a plastics material located in said aperture to make sealing contact with the defining walls of the aperture, a closure member removably mounted in, to make sealing engagement with, the annular insert, and a filter cartridge mounted on the closure member to extend into the housing, the closure member and filter cartridge being locatable on and removable from the housing as a unit.

Abstract: A silencer assembly primarily for the passage therethrough of exhaust gases from an adsorption dryer tower comprises a silencer element to one end of which pressurized gas is directed from an outlet, a control valve downstream of the silencer element, and means for restricting the flow of pressurized gas from the outlet to atmosphere through the silencer element, the arrangement being such that, when the pressure of the gas from the outlet exceeds a predetermined value, the control valve is closed and gas flows from the outlet into and through the silencer element to atmosphere, and, when the pressure of gas from the outlet falls to said predetermined value, the control valve opens and the gas flows from the outlet through the control valve to atmosphere, by-passing the silencer element.