Technical Data Sheet – Diaphragm Pneumatic Actuated Control Valve
(WCB Body + Finned Stem for High Temperature)
Parameter | Specification |
Product Name | Diaphragm Pneumatic Actuated Control Valve |
Valve Type / Model | DN200-PN16-RF (Diaphragm type) |
Nominal Diameter (DN) | 200 mm |
Nominal Pressure (PN) | PN16 (1.6 MPa / 232 psi) |
Connection Type | Flanged |
Flange Face Type | RF (Raised Face) |
Applicable Flange Standard | GB/T 9119 / HG/T 20592 / ASME B16.5 (or as specified) |
Body & Diaphragm Materials
Component | Material Configuration |
Body Material | WCB (ASTM A216 Grade WCB) Carbon Steel Casting |
Body Lining | Unlined / Hard Rubber / FEP / PFA / PP (depending on media corrosivity) |
Diaphragm Material | EPDM / EPDM+PTFE laminated / FKM / PTFE (selected based on media temperature & corrosivity) |
Bonnet / Yoke | WCB Cast Steel |
Stem Configuration: Finned stem (cooling fins) – The bonnet is equipped with annular cooling fins that increase surface area to accelerate heat dissipation from the stem packing area. This effectively reduces the temperature gradient at the packing gland, preventing thermal degradation of sealing components under high‑temperature service. This configuration extends the valve’s applicable temperature range to -29℃ ~ +450℃.
WCB Body Material Data (ASTM A216 Grade WCB)
Parameter | Value |
Standard | ASTM A216 / ASME SA-216 |
Material Type | Carbon steel casting |
Chemical Composition | C ≤ 0.30%, Mn ≤ 1.00%, Si ≤ 0.60%, S ≤ 0.045%, P ≤ 0.04% |
Tensile Strength | 485 ~ 655 MPa (70 ~ 95 ksi) |
Yield Strength | ≥ 250 MPa (36 ksi) |
Elongation | ≥ 22% |
Hardness (NACE sour service) | ≤ 22 HRC |
Heat Treatment | Normalized, normalized & tempered, or quenched & tempered |
Weldability | Good (typical CE 0.45 ~ 0.48) |
WCB Applicable Temperature Range
Service Condition | Temperature Range | Remarks |
Standard operating | -29℃ ~ +425℃ | ASTM A216 standard range |
With finned stem (extended) | -29℃ ~ +450℃ | For high‑temperature applications |
Below -29℃ | Replace with ASTM A352 LCB/LCC | Low‑temperature carbon steel, impact tested |
425℃ ~ 565℃ | Replace with ASTM A217 WC6 | 1.25Cr‑0.5Mo alloy steel |
Above 565℃ | Replace with ASTM A217 WC9 / C5 / C12 | 2.25Cr‑1Mo or high‑Cr alloy |
Important Note: WCB is subject to graphitization above 425℃. For continuous high‑temperature service (e.g., thermal oil), it is recommended to keep the long‑term operating temperature ≤300℃.
WCB Media Compatibility
Media Type | Suitability |
Water, oil, air, steam | Recommended |
Steam (saturated, PN16) | Recommended |
Petroleum products, natural gas | Recommended |
Acetone, alcohol, ammonia, benzene | Suitable |
Sour service (H₂S) | Use with caution – consider C5, CF8 or anti‑sour materials |
Strong acids / strong bases | Not recommended – use stainless steel (CF8/CF8M) or lined body |
Fluoride‑containing media (HF, fluorides) | Strictly prohibited |
Phosphoric acid (>30%, >150℃) | Strictly prohibited |
Actuator Specifications
Parameter | Value |
Actuator Type | Multi‑spring pneumatic diaphragm actuator |
Diaphragm Effective Area | Approx. 1200 cm² (depending on stroke and output force) |
Air Supply Pressure Range | 0.3 ~ 0.7 MPa (recommended 0.4 ~ 0.6 MPa) |
Stroke | 40 ~ 60 mm |
Action Mode | Air‑to‑open (FC – fails closed) or Air‑to‑close (FO – fails open) optional |
Spring Range | 0.02 ~ 0.10 MPa (standard); custom 0.04~0.20 MPa available |
Air Connection | G1/4″ or NPT1/4″ |
Actuator Diaphragm Material | NBR + PET reinforced nylon |
Performance Data
Parameter | Value |
Flow Characteristic | Quick opening (ON‑OFF); with positioner – approximately linear |
Rangeability | 30 : 1 (with positioner) |
Leakage Class | Bubble‑tight seal, meets ANSI/FCI 70‑2 Class VI (zero leakage) |
Shut‑off Differential Pressure | Max. allowable ≥ 1.0 MPa (depends on air supply & spring range) |
Rated Cv Value | Approx. 650 ~ 750 (water, full open, depending on flow path) |
Media Temperature Range | -29℃ ~ +450℃ (with finned stem + high‑temperature diaphragm) |
Optional Accessories
Accessory | Function |
Electro‑pneumatic positioner | 4‑20 mA signal control, improves regulation accuracy |
Filter regulator | Cleans and stabilizes air supply |
Solenoid valve | Remote on/off control of air circuit |
Limit switch box | Provides open/closed position feedback |
Air lock valve | Maintains last position upon air failure |
Manual handwheel | Local manual operation |
Dimensions & Weight (reference)
Parameter | Value |
Face‑to‑face length (L) | Approx. 495 mm (GB/T 12221 series 1, PN16 DN200) |
Overall height (H) | Approx. 850 ~ 1050 mm (depends on actuator & fin height) |
Actuator outer diameter | Approx. 380 ~ 450 mm |
Reference weight | Body ~120 kg + Actuator ~35 kg |
Typical Applications & Media Recommendations
Media Type | Recommended Configuration |
Water, oil, air, steam (≤300℃) | WCB + EPDM diaphragm |
High‑temperature steam, thermal oil (≤300℃) | WCB + finned stem + EPDM+PTFE laminated diaphragm |
Dilute acids / alkalis | WCB with FEP lining + PTFE diaphragm |
Strong acids / alkalis, organic solvents | Change to stainless steel body (CF8/CF8M) + PFA lining + PTFE diaphragm |
Food, pharmaceutical | Change to stainless steel unlined + silicone diaphragm |
Slurries, fibrous media | WCB with wear‑resistant rubber lining + EPDM diaphragm |
Applicable Standards
Standard | Content |
Design & manufacture | GB/T 12239 / ISO 16138 (diaphragm valve standard) |
Flange dimensions | GB/T 9119 / HG/T 20592 / ASME B16.34 |
Body material standard | ASTM A216 / ASME SA‑216 Grade WCB |
Pressure testing | GB/T 13927 / API 598 |
Leakage class | ANSI/FCI 70‑2 Class VI |
Air connection | ISO 228 / G thread |
Critical Notes
- WCB body is NOT suitable for strongly corrosive media (strong acids/bases, fluoride‑containing fluids). Use stainless steel or lined bodies for such services.
- Finned stem is designed for high‑temperature applications. The annular cooling fins on the bonnet reduce packing area temperature and prevent high‑temperature seal failure.
- Continuous high‑temperature operation – Although WCB is rated to 425℃, for continuous high‑temperature service (e.g., thermal oil) it is recommended to limit the long‑term working temperature to ≤300℃ to avoid embrittlement and hardness loss.
- Diaphragm material must match service conditions. For high temperatures, use PTFE or EPDM+PTFE laminated diaphragms. For temperatures above 200℃, consult the supplier for diaphragm temperature rating.
- Low‑temperature service – When media temperature is below -29℃, WCB is subject to cold embrittlement. Replace with ASTM A352 LCB/LCC low‑temperature carbon steel body.
GUATANTEE:
SAVVY VALVES is committed to delivering exceptional product quality and worry-free after-sales service. Our valves are guaranteed to provide a minimum service life of 12 months, during which we will supply all necessary spare parts and detailed maintenance instructions free of charge. Within the warranty period, if any non-human-induced damage occurs, we will replace components at no cost and provide professional technical support. After the warranty expires, customers only need to pay for the cost of spare parts, while still benefiting from discounted maintenance services. Our goal is to help clients reduce operational costs and enhance production efficiency through reliable quality and comprehensive after-sales support. Whether for technical inquiries or maintenance needs, our expert team will respond promptly to ensure your valve system maintains optimal performance at all times.
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