API 6D:2009 pdf download

API 6D:2009 pdf download.Specification for Pipeline Valves.
4.19
obturator
closure member
part of a valve, such as a ball, clapper, disc, gate or plug that is positioned in the flow stream to permit or prevent flow
4.20
operator
device (or assembly) for opening or closing a valve
4.21
packing gland
component used to compress the stem packing
4.22
position indicator
device to show the position of the valve obturator
4.23
piggability
capability of a valve to permit the unrestricted passage of a pig
4.24
powered actuator powered operator
electric, hydraulic or pneumatic device bolted or otherwise attached to the valve for powered opening and closing of the valve
4.25
pressure class
numerical pressure design class expressed in accordance with either the nominal pressure (PN) class or the ASME rating class
NOTE In this International Standard, the pressure class is stated by the PN class followed by the ASME rating class between brackets.
4.26
pressure-containing parts
parts, whose failure to function as intended results in a release of contained fluid into the environment
4.27
pressure-controlling parts
parts, such as seat and obturator, intended to prevent or permit the flow of fluids
4.28
process-wetted parts
parts exposed directly to the pipeline fluid
4.29
reduced-opening valve
valve with the opening through the obturator smaller than at the end connection(s)
4.30
seating surfaces
contact surfaces of the obturator and seat which ensure valve sealing
4.31
stem
part that connects the obturator to the operator and which can consist of one or more components
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4.32
stem extension assembly
assembly consisting of the stem extension and the stem extension housing
4.33
support ribs or legs
metal structure that provides a stable footing when the valve is set on a fixed base
4.34
through-conduit valve
valve with an unobstructed and continuous cylindrical opening
4.35
uni-directional valve
valve designed for blocking the flow in one direction only
4.36
unless otherwise agreed
(modification of the requirements of this International Standard) unless the manutacturer and purchaser agree on a deviation
4.37
unless otherwise specified
(modification of the requirements of this International Standard) unless the purchaser specifies otherwise
4.38
venturi plug valve
valve with a substantially reduced opening through the plug and a smooth transition from each full-opening end to the reduced opening
5 Symbols and abbreviated terms
5.1 Symbols
C flow coefficient in USC units
K flow coefficient in metric units
r thickness
5.2 Abbreviated terms
BM base metal
CE carbon equivalent
DBB double-block-and-bleed
DIB double isolation-and-bleed
DN nominal size
HAZ heat-affected zone
HBW Brinell hardness, tungsten ball indenter
6.2 Valve configurations
6.2.1 Full-opening valves
Full-opening flanged-end valves shall be unobstructed in the fully opened position and shall have an internal bore as specified in Table 1. There is no restriction on the upper limit of valve bore sizes.
Full-opening through-conduit valves shall have a circular bore in the obturator that allows a sphere to pass with a nominal size not less than that specified in Table 1.
Welding-end valves can require a smaller bore at the welding end to mate with the pipe.
Valves with a non-circular opening through the obturator shall not be considered full opening.
6.2.2 Reduced-opening valves
Reduced-opening valves with a circular opening through the obturator shall be supplied with a minimum bore as follows, unless otherwise specified:
valves DN 300 (NPS 12) and below: one size below nominal size of valve with bore according to Table 1;
— valves DN 350 (NPS 14) to DN 600 (NPS 24): two sizes below nominal size of valve with bore according to Table 1;
— valves above DN 600 (NPS 24): by agreement.
EXAMPLE A DN 400 (NPS 16)— PN 250 (class 1500) reduced-opening ball valve has a minimum bore of 287 mm.
Reduced-opening valves with a non-circular opening through the obturator shall be supplied with a minimum opening by agreement.