A pressure regulator includes a cylinder and a piston contained in the cylinder. First and second O-rings are attached to the cylinder and configured to form a seal between the cylinder and an interior wall of the piston. The pressure regulator has a lubrication system that includes a lubrication reservoir between the first and second O-rings defined by an annular groove in an exterior surface of the piston and the interior wall of the cylinder, and an input port extending through the cylinder to the lubrication reservoir. The piston is configured to move along a central axis relative to the cylinder between first and second positions. The first and second O-rings are displaced from the input port during movement of the piston between the first and second positions.

A plug member of a gas valve, having an axial bore, a first bore and a second bore located in a radial direction thereof to respectively communicate with the axial bore, and a first guiding slot and a second guiding slot recessed into an outer peripheral surface thereof. The first bore is larger than the second bore, and communicates with one end of the first guiding slot, while another end thereof is near the second bore. The first guiding slot becomes narrower from the first end to the second end. The second guiding slot has one end communicating with the second bore, and another end located between said first end and said second end.

A plug valve including a valve body defining a cavity and a pair of fluid passages intersecting the cavity, the cavity defining a tapered interior surface of the valve body, a plug extending within the cavity, the plug defining an exterior surface and a fluid passage adapted to be substantially aligned with the fluid passages of the valve body, and an insert extending within the cavity and circumferentially about at least a portion of the plug, the insert defining a pair of fluid passages substantially aligned with the fluid passages of the valve body, respectively. In several exemplary embodiments, the plug valve is used in oil or gas operations, such as, for example, the fracturing or gravel packing of a subterranean wellbore, with the plug valve being used to control the flow of fracturing and/or gravel-packing fluids. Exemplary embodiments of methods associated with the plug valve are also described.

A high pressure fluid system including enhanced safety, maintenance and servicing features. The system can include a CAM assembly module, having a valve seat assembly, seal cartridge assembly and inlet manifold, that is easily installed in and removed from a frame and/discharge manifold as a single unit. A discharge manifold can isolate different pressure rated passageways of the system, and multiple rupture discs associated with the same. A discharge manifold end plate can be included to provide ease of repair of discharge outlets and to establish a plumbing system for the rupture discs. A quick coupler can facilitate connection between a plunger of the seal cartridge assembly and a cross head stub connected to a power frame. A lubrication valve assembly can provide and meter lubrication from a high pressure inlet source to a plunger and packing of the seal cartridge assembly.

A high pressure fluid system including enhanced safety, maintenance and servicing features. The system can include a CAM assembly module, having a valve seat assembly, seal cartridge assembly and inlet manifold, that is easily installed in and removed from a frame and/discharge manifold as a single unit. A discharge manifold can isolate different pressure rated passageways of the system, and multiple rupture discs associated with the same. A discharge manifold end plate can be included to provide ease of repair of discharge outlets and to establish a plumbing system for the rupture discs. A quick coupler can facilitate connection between a plunger of the seal cartridge assembly and a cross head stub connected to a power frame. A lubrication valve assembly can provide and meter lubrication from a high pressure inlet source to a plunger and packing of the seal cartridge assembly.

A ball valve system includes a body having an upstream end and a downstream end and a ball within the body between the upstream end and the downstream end, the ball being rotatable about a vertical axis to move between a closed position and an open position. The ball valve assembly includes a stem movable in an actuation direction substantially parallel to the vertical axis, the stem including a recess at a proximal portion of the stem, a guiding member extending within the recess of the stem, the guiding member being configured to prevent rotation of the stem or cause rotation of the stem, and a lubrication port in fluid communication with the recess.

A high pressure fluid system including enhanced safety, maintenance and servicing features. The system can include a cartridge assembly module, having a valve seat assembly and a seal cartridge assembly selectively joinable with one another and installable within the high pressure fluid system.

A high pressure fluid system including enhanced safety, maintenance and servicing features. The system can include a cartridge assembly module, having a valve seat assembly and a seal cartridge assembly selectively joinable with one another and installable within the high pressure fluid system.

To prevent nuisance marine growth in a valve, particularly a ball valve, used to regulate a flow of seawater, a compound for lubricating and preventing nuisance marine growth is provided in the valve. The nuisance marine growth preventing compound includes a substantially uniform mixture of marine grease and an antifouling agent. The compound is introduced into the valve such that the compound is provided between and contacts a valve body and a ball that regulates the flow of seawater within the valve, and inhibits nuisance marine growth at a space between the ball and the valve body which is occupied by the compound.

A plug member of gas valve has an axial bore, a first bore, and a second bore, wherein the first bore and the second bore are located in a radial direction of the plug member, and communicate with the axial bore, respectively. A diameter of the first bore is larger than that of the second bore. A first guiding slot and at least one first oil groove are recessed into the outer peripheral surface of the plug member, wherein the first guiding slot has a first end communicating with the first bore, and a second end near the second bore without physically communicating with the second end. The at least one first oil groove is near the second end of the first guiding slot without physically communicating with the first guiding slot or the second bore. Whereby, the first oil groove provides space for receiving lubricant.