25-Year Comparison Document for Overhaul of Large-Scale Ammonia Synthesis and Air Separation Units

1. Price comparison conditions
This quotation project—maintenance of large-scale ammonia synthesis and air separation units at Chongqing Xiangyu Salt & Chemical Co., Ltd. for a period of 25 years—has been approved by Chongqing Xiangyu Salt & Chemical Co., Ltd. The project owner is Chongqing Xiangyu Salt & Chemical Co., Ltd., and the project now meets the conditions for competitive bidding. We are hereby inviting quotations and conducting a competitive bidding process for this project.
2. Project Overview and Price Comparison Scope
2.1 Project Location: Within the premises of Chongqing Xiangyu Salt & Chemical Co., Ltd.
2.2 Project Scope: Overhaul of large-scale ammonia synthesis and air separation units within the premises of Chongqing Xiangyu Salt & Chemical Co., Ltd. over a 25-year period.
1) Maintenance items for the ammonia compressor unit: (Low-pressure cylinder model: 3MCL456; High-pressure cylinder model: 3MCL457; Turbine model: T6K48)
1. Inspection and handling of oil leakage from the steam turbine shaft seal of the ammonia compressor.
2. Alignment check of the ammonia compressor coupling.
3. Adjustment of the installation angle of the brush holder for the steam turbine of the ammonia compressor.
4. Disassemble, inspect, and repair the oil leak in the quick-closing valve of the ammonia compressor.
5. Disassemble, inspect, and clean the oil control valve of the ammonia compressor.
6. Inspection and adjustment of the thrust bearings and clearance dimensions for the high- and low-pressure cylinders of the ammonia compressor.
7. Replacement of the nozzle for the ammonia compressor suction ejector.
2) Maintenance items for the syngas compressor unit: (Low-pressure cylinder model: 3V-6; High-pressure cylinder model: 3V-6S; Turbine model: 5CH-6BD)
1. Alignment check of the synthesis gas compressor coupling.
2. Replace the carbon brushes of the syngas compressor.
3. Replacement of the suction nozzle for the syngas compressor ejector.
3) Maintenance items for air separation and air compression units (multi-axis type):
1. Maintenance of air separation and air compressor (Model: STC-GV(125-3); Manufacturer: SIEMENS)
1.1 Remove the manhole of the primary-stage inlet pipe and inspect the air chamber, pipes, and primary-stage guide vanes.
1.2 Replace the metal hoses at the inlet and outlet of the air compressor shaft head pump, as well as the temporary steel straight connectors.
1.3 Replace the multi-layer PTFE gasket at location 1 of the air compressor oil return pipe with a steel ring plus a gasket.
1.4 Leakage Treatment for Remote Measurement Points of Air Compressors (in coordination with Instrumentation and Control).
2. Maintenance of Air Separation Turbine (Model: SST-150LCH-11R; Speed: 5770 rpm; Rated Power: 33,452 kW; Manufacturer: SIEMENS)
2.1 Turbine brush replacement.
2.2 Inspection and Adjustment of Turbine Cat-Claw Clearance.
2.3 Inspection of oil seals on the low-pressure side of the steam turbine and disassembly inspection for oil leakage from bearing covers.
2.4 Inspection of the oil seal on the high-pressure side of the steam turbine.
2.5 Inspection of the tightness of turbine bearing shells.
2.6 Disassembly and inspection of steam turbine radial and thrust bearings.
2.7 Recheck the coupling diaphragms and extension amounts for the turbine-to-air compressor, turbine-to-gearbox, and gearbox-to-boosting unit couplings; also recheck the cold-state alignment.
2.8 Check and pressurize the steam turbine accumulator.
3. Overhaul of Air Separation Booster Compressor (Model: STC-GV(16-5-H); Manufacturer: SIEMENS)
3.1 Removal of the compressor inlet filter screen.
4. Auxiliary equipment maintenance for air separation units:
4.1 The PTFE gaskets on the oil and control oil inlet pipes shall be removed, inspected, and replaced with metal-wound gaskets.
4.2 Clean the fuel tank (excluding draining the fuel from the tank).
4.3 Disassembly and inspection of the ejector nozzle and disassembly and inspection of the secondary air valve.
4.4 Remove, calibrate, and reinstall the 7 safety valves at the gas station.
4.5 Replacement of oil mist fan filter element.
4.6 Oil station filter element replacement (until the oil circulation pressure differential returns to normal).
2.3 Construction Period: The actual maintenance period for the synthetic ammonia unit, starting from the handover of the process equipment, is 5 calendar days; for the air separation unit, it is 4 calendar days after the steam turbine has passed the cold-running acceptance test. The specific maintenance schedule shall be subject to the notice issued by Party A. The maintenance and construction for both the synthetic ammonia and air separation units will be carried out concurrently.
2.4 Project Scope: Overhaul of large-scale ammonia synthesis and air separation units within the premises of Chongqing Xiangyu Salt & Chemical Co., Ltd. for a period of 25 years; see Technical Specifications for details.
2.5 Bidder Requirements
The bidding party (or Party B) must have legal person status and service capabilities that meet the following standards:
1. Provide a valid business license.
2. Possess Grade III or higher professional contracting qualifications in mechanical and electrical installation engineering.
3. Possess a safety production license issued by the relevant national authorities.
4. Workers in special trades must hold valid certifications and be able to verify their credentials through the national online platform.
5. Bidders must provide workers with social insurance, proof of social insurance contributions, and a verifiable means of accessing such information. Construction personnel of the successful bidder must present a labor contract certified by the labor and social security authorities, as well as proof of social insurance contributions, before entering the site. They may only commence construction after successfully passing the safety education and training examination conducted by both the project owner and the tendering party.
6. Provide the organizational structure and personnel qualifications for the corresponding unit’s maintenance.
7. Possess maintenance records for two or more similar models.
3. Maintenance and Acceptance Criteria
The quality of this maintenance inspection, as agreed upon by both parties, must meet the requirements of relevant valid standards and technical specifications.
Maintenance Execution Standard Principles
The maintenance and acceptance standards for large-scale units at Chongqing Xiangyu Salt & Chemical shall comply with the following standard provisions as well as the relevant specifications outlined in the technical documentation provided upon the units’ factory delivery.
GB/T 28573-2012 Petroleum, Petrochemical and Natural Gas Industries — Steam Turbines for General Use
GB/T 28574-2012 Petroleum, Petrochemical and Natural Gas Industries — Steam Turbines for Special Applications
API 611-2022 — Turbines for General Service in the Petroleum, Petrochemical, and Natural Gas Industries
API 617-2022 Axial-Flow, Centrifugal Compressors and Expanders
HG/T 20205-2017 Code for Construction and Acceptance of Chemical Machinery Installation Engineering
SHS 03004-2019 Maintenance and Inspection Procedures for Industrial Steam Turbines.
4. Quotation deadline
Deadline: 5:30 p.m. (Beijing Time), March 18, 2025
5. Contact Information
Price Comparison Person: Chongqing Xiangyu Salt & Chemical Co., Ltd.
Address: No. 98 Longxiang Avenue, Wanzhou District, Chongqing City
Contact: Sun Tongying
Phone: 13517321268

Disclaimer: The official platform for our company’s announcement of this tender is the website of Chongqing Xiangyu Salt & Chemical Co., Ltd.: http://www.cqxyyh.com. Apart from this, our company has not published any tender information on any other websites, forums, or media platforms. Any tender information reproduced from other sources and attributed to our company as the tendering entity is unauthorized and therefore invalid. We reserve the right to pursue legal action against such unauthorized reproductions.