Introduction
The 21241C linear stem lined control valve adopts a structure where the valve body and the internal components are all lined with fluorine. This effectively prevents the corrosive medium from corroding all the metal materials inside the valve body. The internal cavity of the metal valve body is processed by gear-type processing, ensuring that the lined material is fully combined with the metal, thereby increasing the service life and performance of the lined material. The valve stem seal adopts a combination of RTFE bellows seal and V-shaped PTFE packing, completely eliminating the leakage of the medium from the valve stem. The unbalanced full fluorine-lined control valve is specially designed for use in low-pressure and normal-temperature working conditions with highly corrosive media.
Technical Parameter
Control Valve Parameter Description
Valve Body Feature: Unbalanced Valve Core with Inner Sealing Ring
Bellows Valve Stem Seal
Full Enclosed Valve Core
Valve Body Type: Straight Through Type
Upper Valve Cover Type: Bellows Extended Type
Temperature Range: -45°C to 150°C
Valve Stem Seal Type: Standard Packing Seal + Bellows Seal for Double Seal Standard Leakage Grade: CLASS VI (Optional, Soft Valve Seat)
Flow Characteristics: Equal Percentage Linear
Connection to Pipeline: Flange Type
Ratio of Adjustable Capacity: 50:1
Flange Connection Standards
Flange Type: JB/T79.1-94 ~ JB/T 79.4-94 / HG20616-97 ANSI B16.5
Butt Weld Type: GB/T 9124-2000 / ANSI B16.25
Leakage Quantity Compliance Standard: ANSI B16.104
Compatible with Linear Actuator:
a. Pneumatic Diaphragm Actuator
b. Pneumatic Piston Actuator
c. Electric Actuator
d. Electro-hydraulic Actuator
Valve Body Feature: Unbalanced Valve Core with Inner Sealing Ring
Bellows Valve Stem Seal
Full Enclosed Valve Core
Valve Body Type: Straight Through Type
Upper Valve Cover Type: Bellows Extended Type
Temperature Range: -45°C to 150°C
Valve Stem Seal Type: Standard Packing Seal + Bellows Seal for Double Seal Standard Leakage Grade: CLASS VI (Optional, Soft Valve Seat)
Flow Characteristics: Equal Percentage Linear
Connection to Pipeline: Flange Type
Ratio of Adjustable Capacity: 50:1
Flange Connection Standards
Flange Type: JB/T79.1-94 ~ JB/T 79.4-94 / HG20616-97 ANSI B16.5
Butt Weld Type: GB/T 9124-2000 / ANSI B16.25
Leakage Quantity Compliance 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:
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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;
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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.
