Introduction
The 20300 usually adopts a guiding structure. The valve cage is used to compress the valve seat and also serves as the guide for the valve core, making disassembly convenient. The internal components are a single-seat double-valve-core structure. The tight fit between the valve seat and the joint surface of the double-valve-core structure ensures low leakage. It is suitable for controlling various gases and fluids with high pressure differences, compensating for the large leakage of the sleeve double-seat valve and the poor heat resistance of the sleeve single-seat valve. The flow control type design is adopted. When the valve is adjusted or cut off, the small valve core is opened as a means to regulate the flow or release pressure; when the small valve core moves to a certain position, it drives the large valve core to act as a means of regulating or opening the valve.
Technical Parameter
Control Valve Parameter Description
Valve internal component features: Valve cage guided unbalanced internal component cage pressure type valve cage double valve core pressure relief type quick disassembly structure
Valve body type: Straight-through type, Angle type, Z-shaped
Upper valve cover type: Standard at normal temperature, High-temperature heat dissipation type, Low-temperature elongation type
Temperature range: -196°C to 570°C
Valve stem sealing type: Ordinary type standard packing seal
High-temperature type packing seal, Bellows seal
Standard leakage grade: CLASS V (standard type, metal valve seat
CLASS VI (optional type, soft valve seat)
Flow characteristic: Equal percentage, Linear
Connection method with pipeline: Flange type, Welding type
Adjustable ratio: 50:1
Flange connection form standard
Flanged type: JB/T79.1-94 ~ JBIT79.4-94 / HG20616-97 ANSI B16.5
Butt-weld type: GB/T 9124-2000 / ANSI B16.25
Leakage measurement standard: ANSI B16.104
Compatible with linear actuator:
a. Pneumatic diaphragm actuator
b. Pneumatic piston actuator
c. Electric actuator
d. Electro-hydraulic actuator
Valve internal component features: Valve cage guided unbalanced internal component cage pressure type valve cage double valve core pressure relief type quick disassembly structure
Valve body type: Straight-through type, Angle type, Z-shaped
Upper valve cover type: Standard at normal temperature, High-temperature heat dissipation type, Low-temperature elongation type
Temperature range: -196°C to 570°C
Valve stem sealing type: Ordinary type standard packing seal
High-temperature type packing seal, Bellows seal
Standard leakage grade: CLASS V (standard type, metal valve seat
CLASS VI (optional type, soft valve seat)
Flow characteristic: Equal percentage, Linear
Connection method with pipeline: Flange type, Welding type
Adjustable ratio: 50:1
Flange connection form standard
Flanged type: JB/T79.1-94 ~ JBIT79.4-94 / HG20616-97 ANSI B16.5
Butt-weld type: GB/T 9124-2000 / ANSI B16.25
Leakage measurement standard: ANSI B16.104
Compatible with linear actuator:
a. Pneumatic diaphragm actuator
b. Pneumatic piston actuator
c. Electric actuator
d. Electro-hydraulic actuator
Valve Installation & Maintenance
Valve Installation:
(1) Before installation, check that the product model, tag number, and specifications match the requirements. Inspect the entire valve for missing or loose parts.
(2) Prior to installation, clean the pipeline. Ensure there is sufficient straight pipe section at the valve inlet and install a filter. When connecting the valve body to the pipeline flanges, ensure coaxiality.
(3) Thoroughly clean the pipeline before installing the valve.
(4) The installation site should ensure the safety of personnel and equipment, facilitating operation, disassembly, and maintenance.
(5) The valve should be installed vertically upright on horizontal pipelines. If necessary, it can be installed at an angle, but horizontal installation should be avoided. For occasions with heavy valve weight or vibration, use a support frame.
(6) The medium flow direction must align with the arrow on the valve body. The air supply should be dry and oil-free. The valve should be used in environments with temperatures ranging from -20℃ to 55℃.
(1) Before installation, check that the product model, tag number, and specifications match the requirements. Inspect the entire valve for missing or loose parts.
(2) Prior to installation, clean the pipeline. Ensure there is sufficient straight pipe section at the valve inlet and install a filter. When connecting the valve body to the pipeline flanges, ensure coaxiality.
(3) Thoroughly clean the pipeline before installing the valve.
(4) The installation site should ensure the safety of personnel and equipment, facilitating operation, disassembly, and maintenance.
(5) The valve should be installed vertically upright on horizontal pipelines. If necessary, it can be installed at an angle, but horizontal installation should be avoided. For occasions with heavy valve weight or vibration, use a support frame.
(6) The medium flow direction must align with the arrow on the valve body. The air supply should be dry and oil-free. The valve should be used in environments with temperatures ranging from -20℃ to 55℃.
Valve Maintenance:
(1) Cleaning the Valve: For general media, cleaning with water is sufficient. For media harmful to health, first understand their properties and then select an appropriate cleaning method.
(2) Disassembly: Remove rust from exposed rusted parts first. Before derusting, protect the machined surfaces of precision parts such as the valve seat, valve plug, valve stem, and push rod. Use special tools when disassembling the valve seat.
(3) Valve Seat: Minor rust or wear on the sealing surface can be repaired by machining. If damage is severe, replace the seat. However, both repaired and replaced hard sealing surfaces must be lapped.
(4) Valve Stem: If the surface is damaged, it must be replaced.
(5) Damage to Push Rod, Guide, and Sealing Surfaces: Reverse-acting actuators must be replaced; direct-acting actuators can be reused after proper repair.
(6) Compression Spring: If there are cracks or other defects affecting strength, replace it immediately.
(7) Wear Parts: Packing, gaskets, and O-rings must be replaced entirely during each maintenance. Check the valve plug and diaphragm for cracks, aging, or corrosion that may cause future failures. Decide whether to replace them based on inspection results, but the diaphragm service life should not exceed 2-3 years.
(8) When reassembling the valve, ensure alignment. Tighten bolts diagonally and lubricate sliding parts. After reassembly, debug the valve according to the factory test items and methods. During this period, accurately adjust the packing compression force and the valve plug closing position.
(1) Cleaning the Valve: For general media, cleaning with water is sufficient. For media harmful to health, first understand their properties and then select an appropriate cleaning method.
(2) Disassembly: Remove rust from exposed rusted parts first. Before derusting, protect the machined surfaces of precision parts such as the valve seat, valve plug, valve stem, and push rod. Use special tools when disassembling the valve seat.
(3) Valve Seat: Minor rust or wear on the sealing surface can be repaired by machining. If damage is severe, replace the seat. However, both repaired and replaced hard sealing surfaces must be lapped.
(4) Valve Stem: If the surface is damaged, it must be replaced.
(5) Damage to Push Rod, Guide, and Sealing Surfaces: Reverse-acting actuators must be replaced; direct-acting actuators can be reused after proper repair.
(6) Compression Spring: If there are cracks or other defects affecting strength, replace it immediately.
(7) Wear Parts: Packing, gaskets, and O-rings must be replaced entirely during each maintenance. Check the valve plug and diaphragm for cracks, aging, or corrosion that may cause future failures. Decide whether to replace them based on inspection results, but the diaphragm service life should not exceed 2-3 years.
(8) When reassembling the valve, ensure alignment. Tighten bolts diagonally and lubricate sliding parts. After reassembly, debug the valve according to the factory test items and methods. During this period, accurately adjust the packing compression force and the valve plug closing position.
Ordering Instructions
When placing an order, please fill in the Specification Sheet or specify the following information:
-
If the model has not been selected before ordering, please provide us with the operating parameters:
(1) Nominal diameter DN (mm);
(2) Nominal pressure (MPa or bar);
(3) Fluid properties (including medium temperature, viscosity, or acidity/alkalinity);
(4) Pressure before and after the valve (pressure differential);
(5) Requirements for flow characteristics;
(6) Materials of valve body and valve core;
(7) Connection type;
(8) Driving method (provide air supply pressure, driving voltage);
(9) Supporting accessories (for pneumatic valves, it is recommended that users install an air filter triplet and a 2-position 5-way solenoid valve);
(10) On-site working conditions. -
If the product model of our company has been selected by the design unit, please order directly from our production department according to the model;
-
When the application occasion is very important or the pipeline is relatively complex, please provide the design drawings and detailed parameters as much as possible, and our experts will review and check them for you.
