Application And Design Of Fluorine-lined Gate Valves

A lined globe valve regulates corrosive media through a full fluoropolymer lining that isolates the metal body from chemical attack. The disc moves vertically along the stem axis, seating against a lined seat to control flow. PTFE serves continuous service up to 180°C. PFA extends to 200°C for strong oxidizers and high-purity applications. The lining covers all wetted surfaces, including the body interior, seat, and disc.

How to select a lined globe valve

1. Choose lining material: PTFE for standard acids ≤180°C, PFA for strong oxidizers ≤200°C.

2. Select body configuration: through-way for general service, Y-pattern for lower pressure drop.

3. Specify stem sealing: PTFE bellows with backup packing for hermetic sealing.

4. Choose actuation: manual handwheel, pneumatic, or electric based on control requirements.

Common Selection Pitfalls – Why and How to Avoid

• ⚠️ Unlined valves in corrosive media: Metal corrosion causes leakage. → Specify PTFE/PFA-lined construction for all wetted parts.

• 🔴 Overlooking temperature limits: PTFE softens above 180°C, causing liner deformation within weeks. → Specify PFA for services up to 200°C.

• ⛔ Ignoring bellows seal requirements: Standard packing allows atmospheric leakage. → Specify PTFE bellows with backup packing.

• 🛑 Undersizing actuators for throttling: Globe valves require higher thrust. → Verify actuator thrust against maximum differential pressure.

How a Lined Globe Valve Works – Structure and Flow Path

The handwheel or actuator rotates the stem, moving the disc vertically. When the disc lifts off the seat, flow passes through. When the disc descends onto the seat, flow is blocked. The PTFE bellows seals the stem area, preventing leakage to atmosphere.

Body configurations:

• Through-way (Z-pattern): Standard design, suitable for most services

• Y-pattern: 45° seat/stem orientation, lower pressure drop, recommended for high pressure

Lined Globe Valve vs Ball/Butterfly Valves

vs Ball Valve: Ball valves offer low pressure drop but poor throttling capability. Globe valves provide superior control accuracy.

vs Butterfly Valve: Butterfly valves are cost-effective for large diameters. Globe valves offer better shutoff and control precision.

Globe valve advantages:

• Precise flow regulation with linear flow characteristic

• Better shutoff with positive disc-to-seat seal

• Wide rangeability for varying flow conditions

Lining Material Selection – PFA vs PTFE

A ptfe lined globe valve is the standard workhorse for most corrosive services up to 180°C. A pfa lined globe valve offers the same chemical resistance with lower permeation and higher temperature tolerance to 200°C. Pfa lined globe valves are specified for strong oxidizers and high-purity applications.

Stem Sealing – Bellows and Backup Packing

• PTFE bellows: Hermetically seals the product chamber from atmosphere

• Backup V-ring packing: Secondary sealing if bellows fails

• Monitor connection: Allows leak detection

• Travel stopper: Prevents over-compression of PTFE plug and seat

Actuator Selection and Thrust Considerations

• Manual handwheel: Standard for local on-off operation

• Pneumatic actuator: Remote on-off and modulating control; spring-return fail-safe

• Electric actuator: Modulating with position feedback; no instrument air required

• Verify actuator thrust against maximum differential pressure

• ISO 5211 mounting pad enables standard actuator installation

Industry Applications

Chemical Processing: Strong acids, chlor-alkali. PTFE/PFA lining, handwheel or pneumatic actuation, bellows seal.

Pharmaceutical: High-purity API synthesis. PFA lining, electropolished finish, bellows seal.

Petrochemical: Sour water, amine systems. PTFE lining, pneumatic or electric actuation.

Water Treatment: Chemical dosing, chlorine injection. PTFE lining, manual or actuated operation.

Design Summary

PTFE-lined globe valves serve standard acids and caustics up to 180°C. PFA-lined versions handle strong oxidizers up to 200°C. Y-pattern bodies reduce pressure drop. Automated control requires pneumatic or electric actuation with ISO 5211 mounting and thrust verification against maximum differential pressure. Unlike ball valves suited for on-off service, globe valves provide superior throttling control. A pfa lined globe valve is recommended for chlorine, nitric acid, and aqua regia. A ptfe lined globe valve serves standard acid and caustic applications. Y-pattern bodies reduce pressure drop in high-pressure systems.

FVF PTFE Lined Globe Valve With Electric Actuator

• FVF Lined globe valve is fully lined with fluorine materials.It has good anti-corrosive function and it is a better choice to shut-off in corrove pipeline.
• Globe valve refers to the valve with disc driven by stem along the central axis to make lifting movement, is a common block valve,used to connect or throttle medium.
• It has the advantage of compact structure, flexible on-off, strong corrosion resistance, trip shorted and widely applicated in chemical, petroleum, pharmaceutical, food, metallurgy, paper, hydropower, environment protection etc.
• They can be equipped with handwheels or can be actuated with electric or pneumatic actuators. A full range of accessory items are available including limit switches, solenoid valves, positioners and manual override devices.

Product Parameter

Materials of Main Parts

Technical Specification