Pneumatic Steam Globe Valve

Pneumatic Steam Globe Valve / Pneumatic Condensate Line Shut-off Valve – Product Manual
I. Product Overview
The pneumatic steam globe valve (pneumatic condensate line shut-off valve) is a specialized high-temperature steam shut-off valve designed for pipeline flow control. It utilizes compressed air as the power source to drive the stem’s vertical movement. Constructed from cast or forged steel and featuring a metal-to-metal hard seal, it offers excellent temperature and pressure resistance. It is primarily used in steam distribution networks, heat exchange stations, boilers, heat exchangers, and condensate systems for steam shut-off, equipment isolation, and condensate line protection. It can be equipped with solenoid valves, limit switches, and pneumatic positioners for integration into DCS systems for remote automatic control, and configured with a single-acting spring-return mechanism to ensure fail-safe shut-off.

This product serves dual purposes: steam main-line shut-off and condensate branch-line shut-off. In condensate systems, it acts as an upstream isolation valve, facilitating steam trap maintenance and pipeline isolation.
II. Model Designation (Common Types)
J641H: Pneumatic flanged globe valve; H = metal hard seal
J661H: Pneumatic welded globe valve

• J: Globe valve
• 6: Pneumatic actuation
• 4: Flanged connection / 6: Welded connection
• 1: Straight-through pattern
• H: Metal hard seal
  III. Structural Features

1. Straight-through / Streamlined Valve Chamber: The valve seat features a flat or conical metal-to-metal hard seal, ensuring reliable shut-off and resistance to high temperatures and erosion; suitable for saturated and superheated steam applications.
2. Rising Stem Structure: The stem moves vertically (linear motion), providing a clear indication of the opening/closing stroke; the sealing surfaces experience minimal wear, facilitating maintenance and lapping.
3. High-Temperature Gland Packing: Uses flexible graphite packing, offering high-temperature resistance and low fugitive emissions, effectively minimizing stem leakage. 4. Pneumatic Actuator: Double-acting type requires continuous air supply for opening and closing; single-acting type features spring return and automatic closure upon air supply loss, meeting safety interlock requirements for steam systems.
4. Optional Manual Override: Available with an optional manual bypass handwheel for on-site manual operation in the event of an air supply failure.
5. Modular Configuration: Compatible with solenoid valves, air preparation units (FRL), valve position feedback, and positioners; supports either on/off control or proportional modulation. IV. Materials

• Valve Body: WCB cast steel, A105 forged steel
• Disc / Seat: Stellite alloy overlay (wear-resistant and high-temperature resistant)
• Stem: 2Cr13 / F6a stainless steel
• Packing: Flexible graphite
• Gasket: Spiral wound gasket
  V. Technical Parameters
• Nominal Size: DN15–DN300
• Pressure Rating: PN16, PN25, PN40, PN63; Class 150, 300, 600 LB
• Connection Type: Flange (HG20592), Butt-weld (ASME B16.25)
• Actuation: Pneumatic actuator (single-acting spring return / double-acting); optional manual emergency handwheel
• Air Supply Pressure: 0.4–0.8 MPa
• Operating Temperature: -20°C to 425°C
• Applicable Media: Saturated steam, superheated steam, condensate, high-temperature hot water, heat transfer oil
• Leakage Class: Class IV (metal-to-metal hard seal)
• Protection Class: IP65; explosion-proof version (Ex d IIC T6) available
  VI. Application Conditions
  ✅ Recommended Use Cases

1. Boilers, thermal power plants, and heat exchange stations: Remote shut-off for steam main lines and branch lines;
2. Heat exchangers, reactors, and drying equipment: Steam inlet shut-off and isolation for equipment maintenance;
3. Condensate systems: Shut-off valves upstream/downstream of steam traps to isolate condensate branches, facilitating in-line trap maintenance;
4. Automated on/off control for high-temperature steam pipelines in petrochemical, food, and pharmaceutical processes;
5. High-risk steam processes requiring safety interlocks and automatic shut-off upon air supply failure. ❌ Inapplicable Operating Conditions
6. Highly acidic, highly alkaline, or highly corrosive media (use fluorine-lined valves instead);
7. Media containing large amounts of hard particles or causing severe erosion;
8. Operating conditions exceeding rated temperature or pressure limits.
   Not recommended for long-term throttling at small opening angles; prolonged throttling accelerates erosion damage to the sealing surfaces.
   VII. Applicable Standards

• Design & Manufacturing: GB/T 12224, GB/T 12235
• Flange Standards: HG20592, ASME B16.5
• Welding Ends: ASME B16.25
• Pressure Testing: GB/T 13927, API 598
  VIII. Installation and Usage Instructions

1. The flow direction indicated on the valve body must align with the actual medium flow; the medium must enter from beneath the valve disc; reverse installation is prohibited;
2. Purge the pipeline before installation to remove welding slag and scale, preventing scratches on the metal sealing surfaces;
3. Install an air service unit (filter-regulator-lubricator) upstream of the pneumatic circuit to filter and regulate pressure, ensuring the compressed air is clean and dry;
4. Slowly preheat and warm up steam pipelines before operation to prevent water hammer damage to the valve;
5. Long-term throttling at small opening angles is strictly prohibited; if flow regulation is required, a pneumatic control valve is recommended;
6. Periodically inspect the packing; if external leakage occurs, tighten the packing gland evenly;
7. Single-acting spring-return models automatically close upon loss of air supply, meeting process safety interlock requirements.
   IX. Summary of Product Advantages
   The pneumatic steam shut-off valve (pneumatic condensate isolation valve) features metal-to-metal hard sealing and Stellite-faced sealing surfaces, offering resistance to high-temperature steam and erosion. It provides rapid pneumatic response, supports remote DCS control, and includes a fail-safe (close-on-loss-of-air) function in single-acting models. Serving as an isolation shut-off valve within steam piping networks, heat exchange systems, and condensate drainage branches, it facilitates equipment maintenance and acts as a critical valve for safety control in high-temperature steam systems.