ASME B73.1 pdf download Specification for Horizontal End Suction Centrifugal Pumps for Chemical Process
5.1.2 Temperature Limits. Temperature limitations shall be stated by the pump manufacturer. Pumps should be availablefor temperatures up to500°F (260°C). Jacketing and other modifications may be required to meetthe operating temperature. See para.
5.8.3 for auxil- iary piping.
5.2.1 General. Suction and discharge nozzles shall be flanged. Flange drilling, facing, and minimum thick- ness shall conform to ASME B16.5 Class 150 or ASME B16.42 Class 150 standards, except that marking requirements are not applicable and the maximum acceptable tolerance on parallelism of the back of the flange shall be 3 deg. Flanges shall be flat-faced at the full raised-face thickness (minimum) called for in the ASME standards for the material of construction. Raised-face flanges may be offered as an option. Bolt holes shall straddle the horizontal and vertical center- lines. Bolt holes may be tapped when adequate space for nuts is not available behind flanges, as noted in Table 1-1. Through bolt holes are preferred. When tapped holes are supplied, they shall be noted on the outline drawing.
5.2.2 Class 300 Option. As an option, Class 300 flanges in accordance with ASME B16.5 or ASME B16.42 may be offered with pressure ratings subject to the man- ufacturer’s casing pressure–temperature limitations. Class 300 flanges shall be flat-faced at full raised-face thickness (minimum), or raised-face flanges may be offered as an option.
5.2.3 X and Y Dimensions. All pumps, regardless offlange rating, shall conform to the Xand Ydimensions shown in Table 1-1.
5.2.4 HeavyHexNuts. Where heavy hex nuts cannot be used, the location shall be noted on the outline drawing.
NOTE: ASME B16.5 and ASME B16.42 indicate the use of heavy hex nuts for certain flange connections. On many B73 pumps, heavy hex nuts cannot be used due to available space. Standard hex nuts are often substituted. The use of standard hex nuts may not allow the achievement of full bolt stress, which may impact proper gasket compression. With most gasket materials, this does not reduce the gasket’s ability to properly seal. However, this is a consideration for metallic and semimetallic (i.e., spiral wound) gaskets where significant preload may be required to achieve suffi- cient tightness.
5.3.1 Drain Connection Boss(es). Pump casing shall have boss(es) to provide for drain connection(s) in the lowest part of the casing. Boss size shall accommodate 1 ⁄ 2 -in. NPT min. Boss(es) shall be drilled and tapped when specified by the purchaser.
5.3.2 Auxiliary Connection Bosses. The suction and discharge nozzles shall have bosses for gage connec- tions. Boss size shall accommodate 1 ⁄ 4 -in. NPT min., 1 ⁄ 2 -in. NPT preferred. Bosses shall be drilled and tapped when specified by the purchaser. 5.3.3 Support. The casing shall be supported by feet beneath the casing or a suitable support between the casing and baseplate.
5.3.4 Disassembly. The designshall permitremoval of the back pullout assembly from the casing without disturbing the suction and discharge connections. The design shall also avoid disturbing the motor except for assemblies utilizing the C-face motor adapters (see para. 5.12.8). Tapped holes for jackscrews, slots for wedges, or equivalent means shall be provided to facilitate removal of the back pullout assembly. Jackscrews shall not cause damage to parts that will interfere with reassembly and sealing when the parts are reused.
5.3.5 Heating or Cooling 18.104.22.168 There are several methods of cooling or heating areas of most ASME B73 pumps. The sealing cover, pump casing, and bearing housing are areas of the pump that may have design features available for heating or cooling.
22.214.171.124 Jackets for heating or cooling the casing and/or sealing cover are optional. Connections shall be 3 ⁄ 8 -in. NPT min., with 1 ⁄ 2 -in. NPT preferred. When a jacket is to be used for heating by steam, the inlet connection shall be located at the top of the jackets, and the drain connection shall be located at the bottom of the jacket to prevent the formation of water pockets. Jackets for liquid cooling shall have the outlet at the top to prevent the formation ofvapor pockets and a drain at the bottom for freeze protection.
5.3.6 Gasket(s). The casing-to-sealing cover gasket shall be confined on the atmospheric side to prevent blowout.
5.4.1 Types. Impellers may be of the open, semi- open, or closed design.
5.4.2 Adjustment. If axial adjustment is required by the design, the pump shall be provided with a means forexternaladjustmentofthe impellerclearance without disassembly of the pump except for the coupling guard.