API STD 602 2009 pdf free download
API STD 602 2009 pdf free download.Steel Gate, Globe, and Check Valves for Sizes NPS 4 (DN 100) and Smaller for the Petroleum and Natural Gas Industries.
3 Terms and Definitions For the purposes of this document, the following definitions apply. 3.1 class An alphanumeric designation that is used for reference purposes relating to valve pressure/temperature capability, taking into account valve material mechanical properties and valve dimensional characteristics. It comprises the letters “Class” followed by a dimensionless whole number. The number following the letters “Class” do not represent a measurable value and are not used for calculation purposes except where specified in this standard. The allowable pressure for a valve having a class number depends on the valve material and its application temperature and is to be found in tables of pressure/temperature ratings. Prefix “Class” usage is applicable to steel valves bearing NPS nominal size designations. 3.2 diameter nominal DN An alphanumeric designation of size that is common for components used in a piping system, used for reference purposes, comprising the letters “DN” followed by a dimensionless number indirectly related to the physical size of the bore or outside diameter of the end connection as appropriate. The dimensionless number following “DN” does not represent a measurable value and is not used for calculation purposes except where specified in this standard. Prefix “DN” usage is applicable to steel valves bearing PN designations. 3.3 nominal pipe size NPS An alphanumeric designation of size that is common for components used in a piping system, used for reference purposes, comprising the letters “NPS” followed by a dimensionless number indirectly related to the physical size of the bore or outside diameter of the end connection as appropriate. The dimensionless number may be used as a valve size identifier without the prefix “NPS.” The dimensionless size identification number does not represent a measurable value and is not used for calculation purposes. Prefix “NPS” usage is applicable to steel flanges bearing class designations.
4.2.3 For temperatures below the lowest temperature listed in the pressure/temperature rating tables (see 4.1), the service pressure shall be no greater than the pressure for the lowest listed temperature. The use of valves at lower than the lowest listed temperature is the responsibility of the user. Consideration shall be given to the loss of ductility and toughness of many materials at low temperature. 5 Design 5.1 Reference Design 5.1.1 The reference design (the design to be provided when the purchaser does not specify otherwise or does not use Annex E) for sizes NPS ≤ 4 (DN ≤ 100) is for standard bore, bolted-bonnet or cover construction, an outside stem thread for gate and globe valves and, for globe valves, has a conical disc. The reference design for threaded-end valves uses taper pipe threads in accordance with ASME B1.20.1. In addition, for valves NPS ≤ 2 (DN ≤ 50), the reference design is to have a body and bonnet or cover of forged material. Valve parts are identified in Annex D. 5.1.2 Other configurations and types of material may be provided when specified in accordance with Annex E. Requirements for extended body valves are given in Annex A and those for bellows stem seals in Annex B and Annex C. 5.2 Flow Passageway 5.2.1 The flow passageway includes the seat opening and the body ports leading to that opening. The body ports are the intervening elements that link the seat opening to the end connection (e.g. socket or flange). 5.2.2 The minimum cross-sectional area requirement for the standard bore flow passageway applies for both the valve body ports and the seat opening in the absence of the valve disc. The minimum flow passageway cross- sectional area shall not be less than that obtained using the diameters in Table 3.
