1 Scope
This Specification specifies the design, manufacture, inspection and test requirements for centrifugal compressor and its driver and auxiliary equipment in petrochemical industry.
This Specification is applicable to engineering design and equipment procurement of centrifugal compressor in petrochemical industry and used in other industries for reference.
This Specification is not applicable to the compressor with fan, blower and gear increaser, nor centrifugal compressor installed and used on ocean platform.
2 Normative References
The following documents contain provisions which, through reference in this Specification, constitute provisions of this Specification. For dated reference, subsequent amendments to (excluding amending errors) to, or revisions of, any of these publications do not be applied. However, the parties whose enter into agreement according to this Specification are encouraged to research the latest editions of these references are applied or not. For any undated references, the latest edition of the document referred to applies.
GBZ1-2002 Hygienic Standards for the Design of Industrial Enterprises
HG20615 Types and Parameters for Steel Pipe Flanges (American System)
SH3406 Steel Pipe Flanges for Petrochemical Industry
API Std 611 General Purpose Steam Turbines for Petroleum, Chemical and Gas Industry Services
API Std 612 Special Purpose Steam Turbines for Petroleum. Chemical and Gas Industry Services
API Std 613 Special Purpose Gear Units for Petroleum, Chemical and Gas Industry Services
API Std 614 Lubrication, Shaft-Sealin9, and Control-Oil Systems and Auxiliaries for Petroleum, Chemical and Gas Industry Services
API Std 616 Gas Turbine for Refinery Services
API Std 617-1995 Centrifugal Compressors for Petroleum. Chemical and Gas Industry Services
API Std 670 Vibration, Axial-Position, and Bearing-Temperature Monitoring Systems
API Std 671 Special Purpose Couplings For Petroleum, Chemical and Gas Industry Services
ASME Boiler & Pressure Vessel Code. Section VIII, Rules for Construction of Pressure Vessels
ASME B16.1 Cast Iron Piping Flanges and Flanged Fittings
ASME B 16.5 Pipe Flanges and Flanged Fittings NPS l/2 through NPS 24
ASME B16.42 Ductile Iron Pipe Flanges and Flanged Fitting
ASME B16.47 Large-Diameter Carbon Steel Flange
ASME B31.3 Process piping
NACE MR-0175 Sulfide Stress Cracking Resistant Metallic Material for Oil Field Equipment
3 Alternative Design
The Vender may provide alternative design favorable to the parties (the Vendee and the Vender) in the aspects of technical and commercial angles. The alternative design provided by the Vender shall cover detailed description, achievement and standards and specifications. The Vendee will assess the alternative design and make a decision on whether to use it.
4 Terms and Definitions
For the purpose of this Specification, the terms and definitions in API Std 617-1995, 1.4 apply.
5 Basic Design
5.1 General
5.1.1 The compressor unit (including auxiliary equipment) shall be designed and manufactured to reach the service life not shorter than 20 years and the expected continuous operation not shorter than 3 years. This is the system design criteria. Machine provided by the Vender shall have the specification within the design and manufacturing experience of the Vender unless otherwise the Vendee makes a written approval and the experience shows that it is reliable to operate at similar application conditions. At least two units of the same type have operated in the same or similar process conditions for two years and the type of unit may be considered to be reliable.
5.1.2 Unless otherwise specified, the Vender shall take full responsibility of the whole unit (including the centrifugal compressor, gear transmission (if necessary), driver, oil system, control, instrument, coupling, relevant auxiliary equipment and pipeline system), and shall be responsible for their reasonable matching. See Annex A for the supply scope of the Vender. Unless otherwise specified, the centrifugal compressor, driver and its auxiliary equipment shall be applicable to outdoor start and continuous operation under specified ambient conditions.
5.1.3 The Vender shall, according to component of process gas given by the Vendee and their physical property of single component, check and calculate specific heat and compressibility factor of multi-component process gas and other physical parameters of gas necessary to design the compressor and shall take final responsibility for the physical parameters of the gas.
5.1.4 Unless otherwise specified, outlet head of compressor shall be free from any negative deviation under specified flow and an appropriate shaft power shall not exceed 104% of expected value of the Vender. The Vender shall ensure the pressure head, flow and power when the compressor operates at rated condition as required by the process; the compressor shall be able to operate at other conditions required and the pressure head shall meet relevant requirements.
5.1.5 Unless otherwise specified, pressure head - flow characteristic curve shall rise continuously by 5% of rated head at least between normal operation point and surge point; at 110% rated flow, polytropic head shall not be less than 85% of nominal polytropic head. If two compressors are so designed to operate in the same condition and in parallel, the head difference on the two curves shall be less than 2% at any point with equal flow.
5.1.6 Cooling water system shall be designed in accordance with utilities provided by the Vendee and shall be equipped with measures to completely empty and evacuate water therein.
5.1.7 See 2.1.6~2.1.8 in API Std 617-1995.
5.1.8 Selection of all the electrical equipment, electrical elements, instrument and other E&I materials and their installation shall meet the requirements of electrical hazards area classification and site ambient conditions specified by the Vendee data sheet (see Annex B).
5.1.9 See 2.1.11~2.1.14 and 2.1.16~2.1.18 in API Std 617-1995.
5.2 Casing
5.2.1 See 2.2.1~2.2.2 of API Std 617-1995.
5.2.2 Casing outrigger shall be vertical to pedestal and the support leg shall be installed with jackscrew in vertical direction and drilled with lead holes. Vertical stainless steel adjustable pad shall be adopted and jacking measures shall be provided to increase or decrease the adjustable pad.
5.2.3 The Vender shall specify maximum permissible working pressure of casing which shall be at least equal to 1.25 times the sum of maximum suction pressure and maximum possible pressure rise when the compressor operates at the combination of all worst conditions required at the trip speed or at least equal to specified safety valve setting value, whichever is larger.
5.2.4 See 2.2.5~2.2.9 in API Std 617-1995.
5.2.5 Axially split casing shall adopt metal to metal connection (with suitable adhesive agent) and be appropriately bolted up. The axially split connection shall not use gaskets (including ribbon-shaped gasket). If agreed by the Vendee, axially split casing may be connected by o-shaped ring or processed circular groove on the connecting flange surface. If the gasket is used for connection between end cover and cylinder, for the radially split casing, the gasket shall be fastened securely. The gasket shall be in a continuous single sheet structure instead of overlapped or stacked type. Gasket material shall adapt to all the specified service conditions. The sealing face shall have roughness Ra at least 1.57 μm.
5.2.6 See 2.2.11~2.2.15 in API Std 617-1995.
5.2.7 The thread of metric system (ISO/M system) should be adopted for the thread of fasteners. Where the thread of British system (UN/UNC system) is adopted, it shall be approved by the Vendee. The general fasteners thread shall meet the following requirements:
a) The bolts shall be arranged such to leave enough space for socket wrench or ring spanner (external thread only);
b) Bolts with inner hexagon head, castellated nut or monkey spanner type bolts shall not be used unless otherwise agreed by the Vendee;
c) Inner casing fastening bolts shall be tightly locked to avoid fall into air duct.
5.3 Interstage Diaphragms and Inlet Guide Vane
5.3.1 Interstage diaphragms and inlet guide vane shall be appropriate at all the specified operating conditions, start, shut-down, tripping, restoring stability and instant surge. Diaphragms shall be such designed to bear the maximum differential pressure likely to be present at any prescribed operating conditions and in case of loading down or shut-down. Internal fasteners (bolt and nut) in gas circuit shall be arranged in place to prevent fasteners from falling into the gas circuit due to breakdown or looseness to damage the compressor.
5.3.2 See 2.3.2~2.3.3 for API Std 617-1995.
5.3.3 Unless otherwise agreed by the Vendee, the axially split diaphragms shall be used and arranged with hoisting bolt hole or other hoisting measures for easy disassembly. The horizontally split compressor shall have all the diaphragms interlocked with casing.
5.3.4 Unless otherwise specified, partition with internal cooling passage shall not be adopted.
5.4 Casing Connections
5.4.1 General
5.4.1.1 The piping design, manufacture, inspection and test shall meet the requirements of one or more standard(s) among HG20615, SH3406, ASME B31.3, ASMEB16.47 and ASMEB16.5.
5.4.1.2 See 2.4.1.1~2.4.1.5 in API Std 617-1995.
5.4.1.3 All the pores on the casing for connecting pipes shall not be less than DN 20 (3/4 in) and shall be subjected to flange connection or processed into a flat face to be studded or welded. Full-penetration butt welding shall be adopted for all. If the pores are less than DN 25 (1 in), they may be provided with enhanced pipe connection with edges reinforced, but threaded connection shall not be used; If the socket welding is adopted as a connection mode, approval of the Vendee shall be obtained.
5.4.2 Connecting Pipe in Main Process Flow
5.4.2.1 Inlet and outlet shall be flanged or connected with stud after processing plane and the pipe orifice shall face the direction as specified in the data sheet. The connecting pipe at inlet and outlet of barrel compressor shall be arranged on the outer casing but not on the end cover. For the radially split cantilever compressor, connecting pipe at inlet and outlet of process gas may be arranged on end cover.
5.4.2.2 Flange pressure class is ANSI 300 at least and meets the following requirements:
a) Face flange is used only for ductile cast iron casing and full raised face shall be provided;
b) See 2.4.2.2.2~2.4.2.2.3 in API Std 617-1995.
5.4.2.3 If the ductile cast iron flange is equal to or less than DN 200 (8 in), it shall be a face flange and minimum thickness shall be ANSI 300 flange thickness in ASMEB 16.1.
5.4.3 Auxiliary Pipe Connection
5.4.3.1 Auxiliary connection includes, but not limited to connecting pipes for air discharge, liquid filling, sewage discharge, cooling water, lubricating and seal oil, flushing, buffer gas and balance disk cavity.
Foreword I
1 Scope
2 Normative References
3 Alternative Design
4 Terms and Definitions
5 Basic Design
5.1 General
5.2 Casing
5.3 Interstage Diaphragms and Inlet Guide Vane
5.4 Casing Connections
5.4.1 General
5.4.2 Connecting Pipe in Main Process Flow
5.4.3 Auxiliary Pipe Connection
5.5 External Force and External Moments
5.6 Rotating Element
5.7 Bearings and Bearing Housings
5.7.1 General
5.7.2 Radial Bearing
5.7.3 Thrust Bearing
5.7.4 Bearing Housings
5.8 Shaft End Seal
5.9 Dynamics
5.9.1 Critical Speed
5.9.2 Transverse Vibration Analyses
5.9.3 Factory Verification of Imbalance Response Analysis
5.9.4 Torsional Vibration Analyses
5.9.5 Vibration and Balance
5.10 Lubricating Oil and Shaft Seal Oil System
5.11 Materials
5.11.1 General
5.11.2 Pressure Parts
5.11.3 Low Temperature
5.11.4 Pressure Components Material Inspection
5.11.5 Inspection of Impeller Material
5.12 Noise
6 Accessories
6.1 Driver
6.2 Gear Transmission
6.3 Couplings and Guards
6.4 Base Plate
6.4.1 General
6.4.2 Base Plate
6.5 Instrumentation and Controls
6.5.1 General
6.5.2 Flow Rate Control
6.5.3 Local Instrumentation and Control Panel
6.5.4 Instrumentation
6.5.5 Alarm and Shutdown
6.5.6 Electric System
6.5.7 Detector of Vibration, Displacement and Bearing Temperature
6.6 Piping System
6.6.1 General
6.6.2 Process Piping
6.6.3 Auxiliary Piping
6.7 Special Tools
7 Inspection and Testing
7.1 General
7.2 Inspection
7.3 Testing
7.3.1 General Requirements
7.3.2 Hydraulic Pressure Test
7.3.3 Impeller Overspeed Test
7.3.4 Mechanical Operation Test
7.3.5 Gas Leakage Test of Compressor after Assembly
7.3.6 Optional Test
8 Painting, Marking, Package and Shipment
8.1 Painting
8.2 Nameplate and Rotation Arrow
8.3 Marking
8.4 Package and Shipment
9 Guarantee
9.1 Mechanical Guarantee
9.1.1 Shaft End Seal Leakage
9.1.2 Bearing Temperature
9.1.3 Bearing Housing Vibration
9.2 Performance Guarantee
10 Vendor's Data
10.1 General
10.2 Quotation Data
10.3 Contract Data
Annex A (Informative) Referenced Scope of Supply
Annex B (Informative) Format of Data Sheet for Centrifugal Compressor
Annex C (Informative) Comparison of Major Materials Used for Compressor
Annex D (Informative) Supplementary Normative References
Annex E (Informative) Comparison of Piping Materials
Annex F (Informative) Vendor’s Drawings and Documentation
Wording Explanation
1 范围
本规定规定了石油化工用离心式压缩机及其驱动机、辅助设备在设计、制造、检测和试验等方面的要求。
本规定适用于石油化工行业离心压缩机的工程设计及设备采购。其他行业可参照执行。
本规定不适用于通风机、鼓风机和齿轮增速整体组装型压缩机，也不适用于海洋平台上安装使用的离心压缩机。
2 规范性引用文件
下列文件中的条款通过本规定的引用而成为本规定的条款。凡是注日期的引用文件，其随后所有修改单(不包括勘误的内容)或修订版均不适用于本规定，然而，鼓励根据本规定达成协议的各方研究是否可使用这些文件的最新版本。凡是不注日期的引用文件，其最新版适用于本规定。
GBZ1—2002 工业企业设计卫生标准
HG20615 钢制管法兰型式、参数(美洲体系)
SH3406 石油化工钢制管法兰
API Std 611 General Purpose Steam Turbines for petroleum，chemical and gas industry services
API Std 612 Special Purpose Steam Turbines for petroleum. chemical and gas industry services
API Std 613 Special Purpose Gear Units for petroleum，chemical and gas industry services
API Std 614 Lubrication，shaft-sealin9，and control-oil systems and auxiliaries for petroleum，chemical and gas industry services
API Std 616 Gas Turbine for Refinery Services
API Std 617—1995 Centrifugal compressors for petroleum. chemical and gas industry services
API Std 670 Vibration，axial—position，and bearing-temperature monitoring systems
API Std 671 Special Purpose Couplings for petroleum，chemical and gas industry services
ASME Boiler ＆ pressure vessel code. Section VIII，Rules for construction of pressure vessels
ASME B16.1 Cast Iron Piping Flanges and Flanged Fittings
ASME B 16.5 Pipe flanges and flanged fittings NPS l/2 through NPS 24
ASME B16.42 Ductile Iron Pipe Flanges and Flanged Fitting
ASME B16.47 Large-Diameter Carbon Steel Flange
ASME B31.3 Process piping
NACE MR—0175 Sulfide Stress Cracking Resistant Metallic Material for Oil Field Equipment
3 替代设计
卖方可以从技术和商务角度，提供对有关各方(买方，卖方)都有利的替代设计。卖方提供的替代设计应包括详细说明、使用业绩和应用的标准规范。买方将评估此替代设计方案，决定是否采用。
4 术语和定义
本规定所用的术语和定义引用API Std 617—1995第1.4条。
5 基本设计
5.1 一般要求
5.1.1 压缩机组(包括辅助设备)应按照使用寿命至少为20年、预期不间断连续操作至少为3年进行设计和制造。这是系统的设计准则。除买方作出书面认可外，卖方所提供的机器规格应在卖方的设计和制造经验范围内，并且经验证明在相似的使用场合下使用是可靠的。至少应有两台同样型式的机组在相同或相似工艺操作条件下积累两年的成功运行经验，方可认为该型式的机组是可靠的。
5.1.2 除另有规定外，卖方应对整个机组包括离心压缩机、齿轮变速器(如果需要)、驱动机、油系统、控制及仪表、联轴器及相关设备和管道系统等负全部责任，并负责他们之间的合理匹配。卖方的供货范围参见附录A。除另有规定外，离心压缩机、驱动机及其他设备应在规定的环境条件下适用于户外启动和连续操作。
5.1.3 卖方应根据买方给定的工艺气体的组分及各单一组分所固有的物性，核算多组分工艺气的比热、压缩性系数及其他压缩机设计所需的气体物性参数，并对这些气体物性参数负最终责任。
5.1.4 除另有规定外，在规定的流量下压缩机的出口压头不得有负偏差，相应的轴功率不应超过卖方的设计预期值的104％。卖方应保证压缩机操作在工艺要求的额定工况时的压头、流量和功率；同时压缩机也能在其他规定的工况下正常操作，相应的压头应符合规定值。
5.1.5 除另有规定外，压头—流量特性曲线在正常操作点到喘振点之间应连续上升，上升幅度至少为额定压头的5％，并且在110％额定流量时，多变压头不应小于85％额定多变压头。对于按同一操作条件设计的欲并联操作的两台压缩机，两曲线上任—流量相同点的压头差应小于2％。
5.1.6 冷却水系统应按买方提供的公用工程条件设计，系统应设有能全部放空和排净的措施。
5.1.7 引用API Std 617—1995第2.1.6～2.1.8条。
5.1.8 所有的电气设备、电气元件、仪表和其他仪电材料的选择，以及他们的安装都应符合买方数据表(参见附录B)规定的电气危险场所分类及现场环境条件的要求。
5.1.9 引用API Std 617—1995第2.1.11条～2.1.14条、2.1.16条～2.1.18条。
5.2 机壳
5.2.1 引用API Std 617—1995第2.2.1条～2.2.2条。
5.2.2 机壳的支腿应垂直于底座，支脚上应提供垂直方向的顶丝并应钻有引导孔。垂直方向的调整垫应采用不锈钢，并有顶起措施以方便增减调整垫。
5.2.3 卖方应规定机壳的最高允许工作压力，该压力至少应等于最高吸入压力与跳闸转速下压缩机在所有规定工况的最恶劣的组合条件下操作时可能产生的最大升压之和的1.25倍，或至少等于规定的安全阀设定值，两者取较大值。
5.2.4 引用APIStd617—1995第2.2.5条～2.2.9条。
5.2.5 轴向剖分机壳应采用金属对金属的连接(用可合适的粘接剂)，并用适当的螺栓紧固。轴向剖分的连接不应使用垫片(包括带状垫片)。经买方同意，轴向剖分机壳的连接在连接法兰面上可采用O型环或加工的环形沟槽。径向剖分的机壳中，当端盖和筒体间的连接采用垫片时，应将垫片可靠地加以紧固。垫片应为连续的单片结构，不宜采用搭接的或层叠的垫片。垫片材料应适应所有规定的使用条件。密封面粗糙度Ra值至少应为1.57 μm。
5.2.6 引用API Std 617—1995第2.2.11条～2.2.15条。
5.2.7 通用紧固件螺纹宜采用公制(ISO/M制)螺纹，如采用英制(UN/UNC制)螺纹，应经买方认可。通用紧固件螺纹应符合下列要求：
a)螺栓的布置应留有足够的扳手空间，以便使用套筒扳手或梅花扳手(仅外螺纹)；
b)除非买方同意，不应使用带内六角头、带槽螺母或使用活扳手型的螺栓；
c)内壳体紧固螺栓应可靠地锁紧，以避免落入气流通道。
5.3 级间隔板和进口导叶
5.3.1 级间隔板和进口导叶应适于所有规定的运行条件、启动、停车、跳闸、回复稳定及瞬间喘振。隔板应设计成能承受在任何规定的操作条件下以及降负荷或停车时可能出现的最大压差。处于气路中的内部紧固件(螺栓和螺母)应设置在适当位置，以防止紧固件出现故障或松脱进入气路对压缩机造成损坏。
5.3.2 引用API Std 617—1995第2.3.2条～2.3.3条。
5.3.3 除非买方同意，隔板应为轴向剖分结构。隔板应设置吊装用的螺孔或采用其他吊装措施，以便拆卸。水平剖分结构的压缩机所有隔板应与机壳互锁。
5.3.4 除另有规定外，不得采用带内部冷却通道的隔板
