Gaoshan Valve — Q641F Pneumatic Ball Valve

Models: Q641F-16Q  /  Q641F-16C  /  Q641F-25Q  /  Q641F-25  /  Q641F-40  |  Pressure: PN16–PN40  |  Connection: Flanged  |  DN Range: DN20–DN200  |  Type: Pneumatically Actuated Floating Ball Valve

Core Strengths

Product Overview

The Q641F series pneumatically actuated floating ball valve represents Gaoshan Valve’s solution for automated pipeline isolation requiring fast, reliable, remotely-controlled shut-off capability in water, steam, oil, petroleum, and non-corrosive fluid services. Building upon the proven Q41F flanged ball valve platform, the Q641F integrates a double-acting or spring-return pneumatic rack-and-pinion actuator that converts compressed air energy into precise quarter-turn rotary motion for full port opening and closing cycles. Available in five model variants covering three pressure classes (PN16, PN25, PN40) and two body material families (QT450 ductile iron for Q-suffix models, WCB cast steel for C models), the Q641F addresses applications ranging from municipal water distribution automation through heavy-duty industrial process control in refineries and chemical plants. The pneumatic actuation approach offers distinct advantages over electric alternatives including faster response speed, intrinsic safety certification for hazardous areas, lower installed weight, and simpler maintenance with no motor or gear reducer components to service. Internal components including 2Cr13 or 304 stainless steel balls and stems, PTFE soft seat rings, anti-blowout stem designs, and bronze stem bearings are identical to the corresponding Q41F series valves, ensuring parts interchangeability and proven long-term reliability. Face-to-face dimensions comply with GB/T 12221 standards, flange connections follow GB/T 9113 / JB/T 79 specifications, and every valve undergoes rigorous testing per GB/T 13927 requirements.

Performance Specifications by Model

Materials of Main Parts

Main Dimensions — PN16 & PN25 Series (with Pneumatic Actuator)

Main Dimensions — PN40 Series (with Pneumatic Actuator)

* L = Face-to-Face Length, H = Overall Height (to top of pneumatic actuator). Flange connection dimensions refer to GB/T 9113 Flange Dimension Table (Page P95). Technical specifications and main part materials are identical to corresponding Q41F-16Q, Q41F-16C, Q41F-25Q, Q41F-25, and Q41F-40 models.

Structure Drawing

Pneumatic Actuator Options

• Double-Acting (DA): Uses compressed air on both sides of the piston for bidirectional operation. Requires a 4-way directional solenoid valve for control signal routing. Provides consistent torque output in both directions. Recommended for high-cycling applications where air supply is reliable and continuous.
• Spring-Return (SR): Uses compressed air to drive in one direction while pre-loaded springs return the valve to the default position when air is removed. Provides fail-safe operation — automatically closes (or opens) upon loss of air supply or power failure. Essential for ESD (Emergency Shutdown) and safety-interlock applications. Slightly larger actuator profile than DA equivalent.
• Control Accessories: Optional solenoid valves (NAMUR mount), positioners (electro-pneumatic or smart digital), limit switches (mechanical proximity, magnetic Reed, or inductive proximity type), manual override handwheels (with lock-out capability), and air filter regulator units can be mounted directly to the actuator ports per NAMUR VDI/VDE 3845 standard.
• Air Supply Requirements: Standard operating pressure range: 0.4–0.7 MPa (4–7 bar / 58–102 psi) clean, dry instrument air. Air quality: filtered to 40 microns max particle size, dew point at least 10°C below minimum ambient temperature. Flow capacity depends on actuator size and cycle frequency — consult factory for specific air consumption data.

Design & Manufacturing Standards

• Design Standard: GB/T 12237 (Flanged Ball Valves)
• Face-to-Face Dimensions: GB/T 12221
• Flange Standards: GB/T 9113 (RF), JB/T 79 (for PN40)
• Testing & Inspection: GB/T 13927
• Ductile Iron Material: QT450-10 per GB/T 1348
• Cast Steel Material: WCB per ASTM A216 / JB/T 9626
• Actuator Mounting Interface: ISO 5211
• Applicable International Standards: API 608, BS 5351, IEC 60534 (actuator), ATEX (hazardous areas)

Installation & Commissioning Guidelines

• Pipeline Preparation: Clean all pipe ends thoroughly before installation, removing welding slag, scale, rust, and foreign debris. Flush the complete pipeline system to eliminate particles that could damage PTFE seats during first operation or become lodged in actuator internals. Use gaskets rated for the specific pressure class (PN16/25/40) and temperature rating of the application.
• Installation Clearance: Ensure adequate overhead clearance above the valve for the pneumatic actuator height (refer to H dimension table — ranging from 252mm for DN20 to 708mm for DN200). Also allow lateral clearance for actuator end cap access, solenoid valve mounting, and maintenance tool access. For vertical pipe runs, orient the actuator vertically upward unless space constraints dictate horizontal orientation.
• Flange Alignment & Bolt Tightening: Align the valve flanges concentrically with mating pipe flanges before inserting bolts. Tighten flange bolts in a cross-star pattern in multiple incremental passes to achieve uniform gasket compression. Never fully tighten one side first — uneven bolt loading causes body distortion that binds the floating ball against the seats, increasing breakaway torque and causing premature seat wear.
• Pneumatic Piping & Instrumentation: Connect clean, dry instrument air to the actuator inlet ports through an FRL (Filter-Regulator-Lubricator) assembly. Use copper or stainless steel tubing sized for the required flow rate at maximum cycle frequency. Install a block-and-bleed valve upstream of the actuator for isolation during maintenance. Route air tubing away from hot surfaces and protect from mechanical impact.
• Commissioning Procedure: Before pressurizing the actuator, verify the valve is in the correct default position (normally open or normally closed per design intent). Slowly introduce air to the actuator at reduced pressure (~0.2 MPa initially) and check for proper stroke direction and travel limits. Increase to normal operating pressure and perform several full open-close cycles to confirm smooth operation. Check all air connections for leaks using soap solution.
• Positioner & Limit Switch Calibration: If equipped with an electro-pneumatic positioner or smart positioner, calibrate according to the manufacturer’s procedure using the standard 4–20 mA control signal. Verify zero point (fully closed) and span (fully open) accuracy within ±1% of travel. Adjust limit switch trigger points so they activate at 85–95% of full travel to avoid false triggering from vibration.
• Safety Interlock Testing: For fail-safe spring-return actuators, simulate air supply loss by closing the air isolation valve and confirming the valve returns to its safe position (typically fully closed) smoothly and completely. Record the fail-to-safe response time — it should be within the specification (typically under 2 seconds for sizes ≤DN80, under 5 seconds for larger sizes).
• Preventive Maintenance Schedule: Inspect actuator seals and O-rings every 12 months for wear or compression set. Replace internal piston seals proactively every 24–36 months depending on cycle count. Lubricate pinion shaft bearing annually with lithium-based grease. Drain moisture from FRL unit weekly if ambient humidity is high. Replace filter element quarterly or when differential pressure indicator shows restriction.

Application Fields