8″-300LB-RF Diaphragm Pneumatic Actuated Control Valve C/W E/P Positioner
Description
Technical Data Sheet – Diaphragm Pneumatic Actuated Control Valve
(8 Inch, Class 300, WCB Body with Fluoroplastic Lining, with E/P Positioner)
| Parameter | Specification |
|---|---|
| Product Name | Diaphragm Pneumatic Actuated Control Valve |
| Valve Type / Model | 8″-300LB-RF (Diaphragm type, lined) |
| Nominal Diameter (NPS) | 8 inch (DN200) |
| Pressure Class | Class 300 (PN50) per ASME B16.34 |
| Connection Type | Flanged |
| Flange Face Type | RF (Raised Face) |
| Applicable Flange Standard | ASME B16.5 Class 300 |
| Lining Material | FEP / PFA / PTFE (fluoroplastic lining) – selected based on media & temperature |
Body & Diaphragm Materials
| Component | Material Configuration |
|---|---|
| Body Material | WCB (ASTM A216 Grade WCB) Carbon Steel Casting |
| Body Lining | FEP, PFA, or PTFE lining (full lining, including all wetted surfaces) |
| Diaphragm Material | PTFE or EPDM+PTFE laminated (for corrosion resistance & flexibility) |
| Bonnet / Yoke | WCB Cast Steel (with protective coating) |
| Stem | Standard stem (no cooling fins) |
📌 Lining Details: The valve body is fully lined with a fluoroplastic material (FEP, PFA, or PTFE) to provide exceptional corrosion resistance against strong acids, alkalis, and aggressive chemicals. The diaphragm is also PTFE or PTFE-faced to match the lining.
Lining Material Data (FEP / PFA / PTFE)
| Property | FEP | PFA | PTFE |
|---|---|---|---|
| Continuous service temperature | -29℃ ~ +150℃ | -29℃ ~ +180℃ | -29℃ ~ +200℃ |
| Peak temperature (short term) | +175℃ | +200℃ | +230℃ |
| Chemical resistance | Excellent (most acids, alkalis, solvents) | Excellent (similar to PTFE) | Excellent (universal) |
| Permeation resistance | Good | Better than PTFE | Moderate |
| Wear resistance | Moderate | Good | Moderate |
| Typical applications | Strong acids, alkalis, organic solvents | High-purity chemicals, aggressive media | Severe corrosive service |
⚠️ Important: The overall temperature rating of the lined valve is limited by the lining material. Do not exceed the lining’s continuous service temperature.
WCB Body Material Data (for reference – structural only, wetted parts are lined)
| 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% |
| Operating temperature range | -29℃ ~ +425℃ |
Note: The WCB body provides mechanical strength; the fluoroplastic lining provides chemical resistance. The media does not contact the WCB material.
Actuator & Positioner Specifications
| Parameter | Value |
|---|---|
| Actuator Type | Multi‑spring pneumatic diaphragm actuator |
| Actuator Model (Typical) | 5200LA or equivalent |
| Diaphragm Effective Area | Approx. 1600 cm² (for 8″ stroke & force requirement) |
| Air Supply Pressure Range | 0.14 ~ 0.7 MPa (recommended 0.4 ~ 0.6 MPa) |
| Stroke | 40 ~ 80 mm (depending on actuator size) |
| 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 |
| Positioner | Included – Electro‑pneumatic (E/P) positioner (4‑20 mA input) |
Positioner Details (Typical)
| Parameter | Specification |
|---|---|
| Type | Electro‑pneumatic positioner (E/P) |
| Input Signal | 4 ~ 20 mA DC (standard, adjustable to 1/4 split range) |
| Supply Pressure | 0.14 ~ 0.7 MPa |
| Air Consumption | ≤ 0.5 Nl/min (steady state) |
| Output Pressure Range | 0 ~ 0.7 MPa |
| Linearity | ≤ ±1.0% |
| Hysteresis | ≤ 0.5% |
| Repeatability | ≤ 0.5% |
| Enclosure Protection | IP66 (typical) |
| Housing Material | Aluminum alloy or stainless steel (optional) |
| Features | Auto/manual selector, built‑in pressure gauge, optional feedback module |
Performance Data
| Parameter | Value |
|---|---|
| Flow Characteristic | With positioner – Linear or Equal percentage selectable (default: linear) |
| Rangeability | 50 : 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 lining & actuator) |
| Rated Cv Value | Approx. 650 ~ 750 (water, full open, depending on flow path) |
| Media Temperature Range | -29℃ ~ +180℃ (depending on lining material – see lining table) |
| Pressure Rating | Class 300 (PN50) per ASME B16.34 |
Standard Accessories (Included)
| Accessory | Function |
|---|---|
| Electro‑pneumatic positioner (E/P) | 4‑20 mA signal control, precise proportional regulation |
| Filter regulator | Cleans and stabilizes air supply (typically included with positioner package) |
Optional Accessories (Available on Request)
| Accessory | Function |
|---|---|
| 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 |
| Positioner feedback module | 4‑20 mA position feedback signal |
Dimensions & Weight (reference)
| Parameter | Value |
|---|---|
| Face‑to‑face length (L) | Approx. 495 mm (19.5 inches) per ISA-75.08.02 for Class 300 |
| Flange standard | ASME B16.5 Class 300 RF |
| Overall height (H) | Approx. 850 ~ 1050 mm (depends on actuator & positioner) |
| Actuator outer diameter | Approx. 380 ~ 450 mm |
| Reference weight | Body ~120 kg + Actuator ~35 kg + Positioner ~2 kg |
Typical Applications & Media Recommendations
| Media Type | Recommended Configuration |
|---|---|
| Strong acids (HCl, H₂SO₄, HNO₃) | WCB + FEP/PTFE lining + PTFE diaphragm + E/P positioner |
| Strong bases (NaOH, KOH) | WCB + FEP lining + PTFE diaphragm + E/P positioner |
| Organic solvents | WCB + PFA/PTFE lining + PTFE diaphragm |
| Oxidizing agents (chlorine, bleach) | WCB + FEP lining + PTFE diaphragm |
| High-purity chemicals | WCB + PFA lining (low extractables) |
| Hydrofluoric acid (≤50%, ≤150℃) | WCB + special PTFE lining (consult supplier) |
| Corrosive slurries | Not recommended – abrasion damages lining |
| Water, oil, air (non-corrosive) | Suitable (but lining may be unnecessary) |
Applicable Standards
| Standard | Content |
|---|---|
| Design & manufacture | ASME B16.34 / ISA-75.08.02 |
| Lining standard | ASTM F1545 (fluoroplastic lining) |
| Flange dimensions | ASME B16.5 Class 300 RF |
| Body material | ASTM A216 Grade WCB |
| Pressure testing | API 598 |
| Leakage class | ANSI/FCI 70‑2 Class VI |
| Positioner standard | IEC 60534 |
⚠️ Critical Notes for Lined Valves
-
Corrosion resistance – The fluoroplastic lining (FEP/PFA/PTFE) provides excellent resistance to almost all chemicals except molten alkali metals and some fluorine compounds at high temperatures. Always verify compatibility with your specific media.
-
Temperature limitation – The valve’s maximum operating temperature is limited by the lining material. Do not exceed +180℃ for FEP, +200℃ for PTFE/PFA. For higher temperatures, a lined valve is not suitable.
-
Class 300 pressure rating – The valve is designed for Class 300 service per ASME B16.34, suitable for higher pressure applications up to approximately 5.0 MPa at ambient temperature.
-
Avoid vacuum service – Fluoroplastic linings can collapse under vacuum (especially at elevated temperatures). For vacuum applications, a special vacuum-resistant lining design is required. Consult the supplier.
-
Abrasive media – Lined valves are not recommended for abrasive slurries (e.g., with sand, crystals) as they can wear through the soft lining.
-
Electrostatic discharge – For flammable media, ensure the valve has anti-static design (conductive PTFE lining or grounding device).
-
Installation – Use gaskets suitable for lined flanges (full-face gaskets recommended). Do not overtighten bolts to avoid damaging the lining.
-
E/P Positioner is included – Enables precise modulating control with 4-20 mA input signal. Default flow characteristic is linear. Equal percentage available upon request.
📌 Final Selection Checklist (8″-300LB-RF, WCB+Lining, Standard Stem, with E/P Positioner)
| Item | Confirmation |
|---|---|
| ✅ Nominal diameter | 8 inch (DN200) |
| ✅ Pressure class | Class 300 |
| ✅ Body material | WCB with fluoroplastic lining |
| ✅ Lining type (to be confirmed) | FEP / PFA / PTFE |
| ✅ Stem type | Standard (no cooling fins) |
| ✅ Positioner | E/P Positioner included (4‑20 mA input) |
| ✅ Media temperature range | -29℃ ~ _____℃ (max. lining limit) |
| ✅ Service media (to be confirmed) | ___________ |
| ✅ Diaphragm material | PTFE / EPDM+PTFE laminated |
| ✅ Action mode (to be confirmed) | Air‑to‑open (FC) / Air‑to‑close (FO) |
| ✅ Vacuum service? | Yes / No (if yes, special design required) |
| ✅ Additional accessories | Solenoid valve / Limit switch / Handwheel |
Note: The critical notes marked with ⚠️ are key selection criteria. It is recommended to verify all process parameters with the supplier before ordering to ensure long‑term reliable operation.
Let me know if you would like to adjust the lining material, change the flow characteristic, or modify any other parameter.
