An arrangement with a valve having a valve housing and a closure member mounted for movement in an interior space of the valve housing between a closed position and an open position by a valve drive. The closure member closes valve housing openings in the closed position and opens them in the open position. The arrangement has an attachment part with an attachment part housing and a push tube, and the push tube is mounted displaceably in the attachment part housing. The attachment part housing and the push tube together enclose a line cavity of the attachment part for conducting a fluid through the attachment part. The attachment part housing is fastened on the outside to the valve housing, and the push tube can be pushed through the interior space of the valve housing when the closure member is in the open position.

An arrangement with a valve having a valve housing and a closure member mounted for movement in an interior space of the valve housing between a closed position and an open position by a valve drive. The closure member closes valve housing openings in the closed position and opens them in the open position. The arrangement has an attachment part with an attachment part housing and a push tube, and the push tube is mounted displaceably in the attachment part housing. The attachment part housing and the push tube together enclose a line cavity of the attachment part for conducting a fluid through the attachment part. The attachment part housing is fastened on the outside to the valve housing, and the push tube can be pushed through the interior space of the valve housing when the closure member is in the open position.

In embodiments, a gate valve includes a valve body including a flow passage from a first opening to a second opening, and a gate channel having a first end intersecting the flow passage and a second end delineated by a third opening. A valve cover fits over the third opening. A cap fits over a valve cover opening. In embodiments, a valve cover includes a body with a second sealing surface protruding from a first sealing surface, both around an opening of the body. A cap has a third sealing surface to mate with the first sealing surface, and a fourth sealing surface congruent to the second sealing surface. In embodiments, a valve cover cap includes a body with a first sealing surface on an end of a wall. Pin flanges each have a pin hole having a pin hole axis oriented perpendicular to a center axis of the wall.

In embodiments, a gate valve includes a valve body including a flow passage from a first opening to a second opening, and a gate channel having a first end intersecting the flow passage and a second end delineated by a third opening. A valve cover fits over the third opening. A cap fits over a valve cover opening. In embodiments, a valve cover includes a body with a second sealing surface protruding from a first sealing surface, both around an opening of the body. A cap has a third sealing surface to mate with the first sealing surface, and a fourth sealing surface congruent to the second sealing surface. In embodiments, a valve cover cap includes a body with a first sealing surface on an end of a wall. Pin flanges each have a pin hole having a pin hole axis oriented perpendicular to a center axis of the wall.

A valve seat assembly includes a body having an insert pocket with an axially extending inner surface and a radially extending bottom surface. The valve seat further includes an insert disposed within the insert pocket of the body. The insert includes an axially extending outer surface and a radially extending bottom surface for mating with the axially extending inner surface and a radially extending bottom surface of the insert pocket of the body. The axially extending inner surface of the body is formed with a non-zero reverse taper angle, A.sub.4, for securing the insert within the insert pocket of the body. The axially extending outer surface of the insert is formed with a reverse taper angle, A.sub.5, equal to or greater than zero degrees. A valve assembly includes a valve and the valve seat assembly in reciprocating contact with the valve.

A valve seat assembly includes a body having an insert pocket with an axially extending inner surface and a radially extending bottom surface. The valve seat further includes an insert disposed within the insert pocket of the body. The insert includes an axially extending outer surface and a radially extending bottom surface for mating with the axially extending inner surface and a radially extending bottom surface of the insert pocket of the body. The axially extending inner surface of the body is formed with a non-zero reverse taper angle, A.sub.4, for securing the insert within the insert pocket of the body. The axially extending outer surface of the insert is formed with a reverse taper angle, A.sub.5, equal to or greater than zero degrees. A valve assembly includes a valve and the valve seat assembly in reciprocating contact with the valve.

A gate valve includes a valve body and a valve cover. The valve body includes a first opening, a second opening, a third opening, a flow passage from the first opening to the second opening, and a gate channel from the flow passage to the third opening. The gate channel has a central longitudinal axis and a ridge defining a perimeter of the third opening. The valve cover can fit over the third opening and, under force on the valve cover, exert a clamping force on the ridge. The clamping force has a first force component perpendicular to the central longitudinal axis and a second force component parallel with the central longitudinal axis. The first force component of the clamping force is toward the gate channel. The ridge includes a first surface configured to mate with a first surface of the valve cover.

A gate valve includes a valve body and a valve cover. The valve body includes a first opening, a second opening, a third opening, a flow passage from the first opening to the second opening, and a gate channel from the flow passage to the third opening. The gate channel has a central longitudinal axis and a ridge defining a perimeter of the third opening. The valve cover can fit over the third opening and, under force on the valve cover, exert a clamping force on the ridge. The clamping force has a first force component perpendicular to the central longitudinal axis and a second force component parallel with the central longitudinal axis. The first force component of the clamping force is toward the gate channel. The ridge includes a first surface configured to mate with a first surface of the valve cover.

A gate valve and a seat insert for a gate valve having a valve body, which may be used for hydrocarbon well fracturing operations with a fracturing fluid, or “frac fluid”, includes a seat pocket for receipt of the seat insert and a seat, which seat insert may include a tubular member having a first and a second seat insert end face, the first and second seat insert end faces each include at least one annular seal, and the seat insert is disposed in the seat pocket with the first seat insert end face sealed against the valve body and the second seat insert end face sealed against the seat.

Provided is a flow rate adjustment device including: a diaphragm integrated valve body; a valve seat section provided around an inflow opening and including a valve seat surface disposed at a position facing a valve surface; and a transfer mechanism configured to cause the diaphragm integrated valve body to move along an axis line to adjust a distance between the valve surface and the valve seat surface. The valve surface 11a and the valve seat surface form an angle, which is an acute angle, with the axis line and are disposed in parallel.