Safety Valve Muffler Technical Requirements
3.2.1 The safety valve silencer is a vertical cylindrical silencer, which should be equipped with a damping device and a temperature-reducing cooling water system. The effective volume is 5m³, and the exhaust steam pipe is directly connected to the atmosphere. This equipment is equipped with two DN350 drain main pipe interfaces, which are divided into high-pressure and low-pressure main pipes according to the pressure levels. Measures to prevent the mutual interference of the drain water from each main pipe during expansion should be taken inside the expansion vessel. The expansion vessel also has an exhaust steam pipe interface with DN500 and a drain pipe interface with DN100. A steam exhaust silencer is provided.
3.2.2 The working medium in the demister expansion vessel is mainly main steam, reheated steam, auxiliary steam, pipeline demisting, and part of the steam. The top of the vessel expands and discharges, while the bottom discharges condensate water. Water spray atomization is used for temperature reduction, with the cooling water sourced from condensate water at a pressure of 1.5 to 2.6 MPa.
3.2.4 Vessels shall be selected and designed by the bidder in accordance with the specified conditions of the data sheet, and should meet the requirements of this specification for the shape, interfaces, supports, and instruments of all vessels.
3.2.5 The main pressure components of the hydrophobic expansion vessel should not be less than Q345R. The thickness of structural sections should not be less than 8mm, with a minimum corrosion allowance of 2mm. For steel structures and internal supports in tanks without internal protective coatings, the calculated cross-sectional thickness should be increased by the allowable corrosion value.
3.2.6 The hydro-expansion vessel should undergo a hydrostatic test, with the test pressure being 1.5 times the design pressure.
3.2.8 The hydrophobic expansion vessel is supplied with all interfaces and paired flange connection accessories, including safety valves and their respective brackets.
To ensure safe and reliable operation, the demister expansion vessel should be capable of withstanding the adverse combination of all possible loads under all operating conditions. It should at least include:
(1) High pressure and pressure fluctuations occurring internally within the equipment.
(2) Equipment weight under operation or testing conditions, including self-weight and water weight;
(3) The forces and torques transmitted from the external piping system to the saddle.
Seismic Load Test
3.2.10 Life Expectancy Requirements
Bidder shall ensure the lifespan of the demister expansion vessel equipment is 30 years.
(2) The lifespan of container equipment must take into account the comprehensive impact of various environmental conditions during its use.
All flanged interfaces and pipe fittings with flanges, supplied by the tenderers, should be equipped with reverse flanges, connecting parts, and accessories.
3.2.12 Material Inspection: Complies with a complete quality assurance certificate and material physical and chemical report.
3.2.13 Paint: The inner surface should be clean, smooth, and free of rust spots, and coated with two layers of heat-resistant steam drum paint. The outer surface should be coated with two layers of anti-rust paint. The color of the topcoat will be determined by the bidder.
All flanges must comply with relevant standards and should extend at least 150mm beyond the housing.
3.2.15 All required connectors, accessories, and fittings should be provided with the container.
3.2.16 Provide normal exhaust and accident exhaust measures for the container (equipped with a safety valve). Prevent the formation of a vacuum inside the container under all normal and accident conditions.
3.2.17 The container should provide at least one manhole.
3.2.18 The desiccant expander should have a complete hydrostatic test report and factory inspection certificate.
3.3 Sulfur Water Expander Manufacturing Requirements
3.3.1 Water-stop plates must be installed on the containers, and the design rigidity, strength, and stability of the equipment must meet the requirements of the local seismic intensity. Reinforcement ribs must be set at the top of the container. The layout location of the drain expansion vessel is inside the indoor condensate pump pit.
The design of containers for processing and assembly within the factory should allow for overall movement. Two lifting lugs must be provided, each capable of lifting the entire unit. Additional lugs should be set according to necessity to enable the container to be pulled horizontally. The roof of vertical containers should be self-supporting, without the need for internal supports.
The container should be a welded structure. The brackets for the container attachments, made from material similar to the box body, are welded to the box. The internal support brackets should be at least 9mm thick, and the fasteners, including bolts and U-bolts used to secure the container's internal piping to the support brackets, should not be smaller than 9mm in diameter.
3.3.4 Vertical containers should be equipped with support feet or aprons and anchoring plates. The supports of vertical containers should be welded along the tangential direction to the body, and the internal reinforcing components should be provided with drainage holes.
3.3.5 Reinforcement for openings in containers (including reinforcement for pipe loads) should be designed in accordance with applicable standards. Each reinforcement or other component (if more than one is used) should be equipped with two monitorable screw holes for draining water from the hydrostatic test joint.
3.3.6 Vertical seams on the container should be avoided around openings and reinforcing elements.
3.3.7 The annular seams on the container should be avoided around openings and reinforcing members as much as possible. When openings must be located at these seams and reinforcing pads are required, the ring welds should be ground flat and inspected before the reinforcing pads are installed.
