API STD 685-2000 pdf free download

API STD 685-2000 pdf free download.Sealless Centrifugal Pumps for Petroleum, Heavy Duty Chemical, and Gas Industry Services.
6.14.3.1 Impact testing is not required for parts with a gov- erning thickness (6.14.5) of 25 mm (1 in.) or less. 6.14.3.2 Impact testing exemptions for parts with a gov- erning thickness (6.14.4) greater than 25 mm (1 in.) shall be established in accordance with paragraph UCS-66 in Section VIII, Division 1 of the ASME Code. Curve A shall be used for all carbon and low alloy steel materials (including cast- ings) which are not specifically listed for curves B, C, or D. Minimum design metal temperature without impact testing may be reduced as shown in figure UCS-66.1. If the material is not exempt, Charpy V-notch impact test results shall meet the minimum impact energy requirements of paragraph UG- 84 of the ASME code. 6.14.4 Governing thickness used to determine impact test- ing requirements shall be the greater of the following: a. The nominal thickness of the largest butt welded joint. b. The largest nominal section for pressure containment, excluding: 1. Structural support sections such as feet or lugs. 2. Sections with increased thickness required for rigidity to mitigate shaft deflection. 3. Structural sections required for attachment or inclusion of mechanical features as jackets or seal chambers. c. One fourth of the nominal flange thickness (in recognition that the predominant flange stress is not a membrane stress). 6.14.5 The purchaser will specify the minimum design metal temperature used to establish impact test requirements. Note: Normally, this will be the lower of the minimum surrounding ambient temperature or minimum liquid pumping temperature. However, the purchaser may specify a minimum design metal tem- perature based on pumpage properties, such as autorefrigeration at reduced pressures. 6.15 NAMEPLATES AND ROTATION ARROWS 6.15.1 A nameplate shall be securely attached at a readily visible location on the equipment and on any other major piece of auxiliary equipment.
6.15.3 In addition to being stamped on the nameplate, the pump serial number shall be plainly and permanently marked on the pump casing. 6.15.4 Rotation arrows shall be cast in or attached to each major item of rotating equipment at a readily visible location. 6.15.5 Nameplates and rotation arrows (if attached) shall be of austenitic stainless steel or of nickel-copper alloy (Monel or its equivalent). Attachment pins shall be of the same material. Welding is not permitted. 7 ACCESSORIES 7.1 MOTORS Note: The motor requirements in this section apply to both canned motor pumps and magnetic drive pumps. See Section 5.2.2 for addi- tional requirements for canned motor pump motors. 7.1.1 The driver shall be sized to meet the maximum speci- fied operating conditions, including all losses, as applicable, and shall be in accordance with the applicable specifications, as stated in the inquiry specification, datasheets, and order. The driver shall be suitable for satisfactory operation under the utility and site conditions specified. 7.1.2 Anticipated process variations that may affect the siz- ing of the driver (such as changes in pressure, temperature, or properties of the liquid handled, as well as special plant start- up conditions) will be specified. 7.1.3 The starting conditions for the driven equipment will be specified, and the starting method shall be mutually agreed upon by the purchaser and the vendor. The driver’s starting torque capabilities shall exceed the speed-torque require- ments of the driven equipment. 7.1.4 Motors will be sized in accordance with 7.1.4.1 and 7.1.4.2.
7.1.4.2 When specified, motor shall be sized to cover max- imum power for the rated impeller. 7.1.5 Motors shall be designed to operate under running conditions at rated load and frequency with a voltage varia- tion of 10 percent or less, above or below rated voltage. 7.1.6 Motors shall be designed to operate under running conditions at rated load and voltage with a frequency varia- tion of plus or minus 5 percent of rated frequency. 7.1.7 Motors shall be designed to operate under running conditions at rated load with a combined variation of voltage and frequency up to 10 percent above or below the rated volt- age and the rated frequency, provided that the frequency vari- ation does not exceed 5 percent. 7.1.8 The motor’s starting torque requirements shall be met at reduced voltages specified by the purchaser, and the motor shall accelerate to full speed within a period of time agreed upon by the purchaser and the vendor. Note: For most applications, the starting voltage is typically 80 per- cent of the normal voltage, and the time required to accelerate to full speed is generally less than 15 seconds. 7.1.9 For variable speed motors, the vendor shall ensure that the drive characteristics fully meet all requirements, such as motor cooling, supply waveforms/harmonics, rotor mechanical integrity, and torque availability/requirements for acceptable start-up and operating conditions. 7.1.10 For variable speed motors, the vendor shall identify and supply any input/or output line reactors that may be required to ensure reliable operation of the pump and power supply system to which it will be connected, under all operat- ing conditions.