AS 6401:2003 pdf – Knife-gate valves for waterworks purposes

AS 6401:2003 pdf – Knife-gate valves for waterworks purposes.
The valves are designed for operation by manual hand wheel either above ground or buried or submerged s ith an extension spindle.
Means for demonstrating compliance with this Standard are given in Appendix A.
NOTES:
1 Purchasing guidelines are given in Appendix B.
2 The design of the extension spindle is not covered in this Standard.
1.2 REFERENCED DOCtMENTS
The documents referred to in this Standard are listed in Appendix C.
1.3 DEFINITIONS
For the purpose of this Standard, the detinitions below apply.
1.3.1 Knife-gate vah’e
A valve that provides on/off control by means of a thin, parallel sliding gate and guide.
1.3.2 Allowable operating pressure
The allowable internal pressure, excluding surge, that a component cait safely withstand in
service.
1.3.3 Maxiniurn allowable operating pressure
The allowable internal pressure, including surge. that a component can safely withstand in
service.
1.3.4 Allowable test pressure
The maximum internal hydrostatic pressure that can be applied on site to a component in a newly installed pipeline.
1.3.5 Hi-directional
The valve is designed to seal against the flow in either direction.
The allowable operating pressure of the valve expressed in hundreds of kilopascals.1.3.8 Coating
A corrosion-inhibiting medium applied to the surfaces of a valve.1.3.9Coating defect
A detectable weakness or discontinuity in a coating which deems it to be suspect in itsability to protect the substrate from corrosion during its normal service life.
1.3.10 Distortion
Any permanent deformation.1.3.11 DN (Nominal size)
An alphanumeric designation of size for components of a pipework system， which is usedfor reference purposes. It comprises the letters DN followed by a dimensionless wholenumber that is indirectly related to the physical size, in millimetres, of the bore or outsidediameter of the end connections.
1.3.12 Face to face dimensions
The distance between the valve mating faces measured along the valve axis.1.3.13 Free end test
A test where the valve ends are blanked off so that the axial hydraulic force is notexternally restrained. This simulates a valve in a terminal position held rigidly at one endonly.
1.3.14 Non-rising spindle design
A valve design where the gate is attached to the spindle, such that as the gate moves fromclosed to open position the spindle does not rise during operation.
1.3.15 Rising spindle design
A valve design where the gate is fixed to the spindle such that as the gate moves fromclosed to open position the spindle rises during operation.
1.3.16Un-directional
The valve is designed to seal against the flow in one direction only1.3.17Type test
A once only set of tests carried out to prove performance.1.4 VALVE TYPE
Valves shall be of the wafer,flanged or lugged type for installation between flanges,or forinstallation at a termination point.
The valve may be supplied in any of the following configurations:
(a) Rising or non-rising spindle.
(b) Uni-directional or bi-directional flow.
(c)Yoke and gland box or bonneted valve spindle support system.