A slide valve having a valve disc that is slidably movable between a fully-retracted fully-open position and a fully-extended fully-closed tight shutoff position by an actuating stem. The actuating stem is flexibly coupled to the valve disc. The valve disc is selectively modulated between the fully-extended fully-closed tight shutoff position and a partially-retracted non-tight shutoff position to prevent sticking of the valve disc in the fully-extended fully-closed tight shutoff position.

A valve component comprising a substrate with a sliding surface, the sliding surface being designed to be subjected to sliding against another surface during operation of the valve, wherein at least a portion of the sliding surface is coated with a coating comprising an under-layer comprising tungsten and an upper-layer deposited atop the under-layer, said upper-layer comprising diamond-like-carbon, wherein the under-layer comprises carbon and has a layer thickness of at least 11 micrometers, and the upper-layer has a lower coefficient of friction than the under-layer and has a layer thickness of at least 1.5 micrometers.

A hydraulic machine includes a first member (1) having a first structure (2) for a hydraulic medium opening in a first interface surface (3) and a second member having a second structure for the hydraulic medium opening in a second interface surface is described, the first interface surface (3) being in contact with the second interface surface, wherein at least one of the members (1) is provided with a support element (6) surrounding the member (1). Such a machine should have a good efficiency. To this end the support element (6) has a strength varying in circumferential direction around the member (1) and/or in thickness direction in a middle region of the member (1).

A slide valve having a valve disc that is slidably movable between a fully-retracted fully-open position and a fully-extended fully-closed tight shutoff position by an actuating stem. The actuating stem is flexibly coupled to the valve disc. The valve disc is selectively modulated between the fully-extended fully-closed tight shutoff position and a partially-retracted non-tight shutoff position to prevent sticking of the valve disc in the fully-extended fully-closed tight shutoff position.

A method of manufacturing a device includes thermally spraying tungsten carbine in feedstock that does not include Cobalt but that includes Nickel, Copper, or a Nickel-Copper alloy, the method improves the base coating toughness, anticorrosion, and antifouling properties for high load application in sea water and brackish water environments. Additionally, a Cobalt-free material lowers material costs and reduces the global demand of Cobalt. Providing a topcoat of a Silicon-doped DLC significantly reduces the topcoat brittleness of common DLC failures such as “egg shell” in high stress applications. Thus, high hardness, low friction applications may be tailored in high stress applications.

A ring base member of a disc seat ring is fixed to a valve disc using a bolt. The valve disc is formed of a first austenitic stainless steel containing 17.0% by mass to 21.0% by mass of Cr and 8.0% by mass to 13.0% by mass of Ni. The ring base member is formed of a second austenitic stainless steel containing 17.0% by mass to 20.0% by mass of Cr and 8.0% by mass to 15.0% by mass of Ni.

The invention provides a gate valve (1) for control of petroleum production or water injection, distinctive in that at least one surface subject to sliding in operation of the valve comprises a top layer coating of diamond like carbon (DLC). The DLC contains hydrogen, preferably more than 16 atom-% and more preferred more than 17 atom-%. It is further directed to a method of commissioning or operating a gate valve according to the invention, and use of a diamond like carbon (DLC) top layer coating on at least one surface subject to sliding in operation of the gate valve. Valve parts have a tendency of sticking, adhering or cold welding together, which result in high friction. The aim of the invention is to reduce or eliminate friction problems occurring with time or operation cycles, when using a full scale gate valve.

An inlet port provides a fluid entrance to a body. A chamber has an inner surface. An outlet port is in fluid communication with the chamber and provides a fluid exit from the body. The piston is moveable within the chamber between a first set position, in which the inlet port is not in fluid communication with the outlet port, and a second open position, in which the inlet port is in fluid communication with the outlet port through the chamber. A seal guard is slidably disposed within the chamber. The seal guard is moveable between a first seal-guard position and a second seal-guard position in which the seal guard shields the seal. The seal guard is in the first seal-guard position when the piston is in its first set position and in the second seal-guard position when the piston is in its second open position.

A ring base member of a disc seat ring is fixed to a valve disc using a bolt. The valve disc is formed of a first austenitic stainless steel containing 17.0% by mass to 21.0% by mass of Cr and 8.0% by mass to 13.0% by mass of Ni. The ring base member is formed of a second austenitic stainless steel containing 17.0% by mass to 20.0% by mass of Cr and 8.0% by mass to 15.0% by mass of Ni.

Example devices include a fluidic device, such as a fluidic valve, including a body formed from a rigid body material including a fluidic source, a fluidic drain, and a fluidic gate, each of which may have a fluid connection with a chamber, or a portion thereof. The device may further include a gate transmission element, located within the chamber, that is controllable between at least a first position and a second position using a gate pressure received through the fluidic drain. Adjustment of the position of the gate transmission element may allow control of fluid flow through the device. Other devices, methods, systems, and computer-readable media are also disclosed.