Halar Coated Disc Butterfly Valve

The Halar coated disc butterfly valve is engineered for extreme chemical environments, utilizing Halar (ECTFE) coating on the disc surface to achieve superior corrosion resistance. With a service temperature range of -40℃ to 150℃ (the specific temp. application also need considering the seat materials) and thickness of 0.5-1.2mm.

The core function of HALAR coating

HALAR (ethylene-chlorotrifluoroethylene copolymer, ECTFE) is a high-performance fluoropolymer that evenly covers the surface of the butterfly plate through an electrostatic spraying process to form a dense protective layer with a thickness of 0.5~1.2mm. In theHalar coated disc butterfly valve, the core functions of this coating include:

1. Chemical corrosion resistance: It can withstand 98% sulfuric acid, 37% hydrochloric acid, strong alkali (such as 50% NaOH) and organic solvents (such as acetone, xylene), and the corrosion rate is less than 0.01mm/year;

2. Temperature resistance: Long-term use temperature range -40℃~150℃, short-term resistance to 180℃thermal shock;

3. Low permeability: The molecular structure is dense, preventing the metal substrate of the butterfly plate from corroding due to medium penetration;

4. Wear resistance and anti-sticking: The surface friction coefficient is as low as 0.3, which reduces the adhesion of granular media and extends the maintenance cycle.

5. Compared with PTFE or PP coatings, the mechanical strength of HALAR is increased by more than 50%, especially under frequent opening and closing conditions, which can prevent the coating from cracking and falling off.

Structural optimization:

To adapt to the physical properties of the HALAR coating, ourHalar coated disc butterfly valve adopts targeted design:

1. Precision machining of butterfly plate: The base material is made of 316L stainless steel or duplex steel, and the surface roughness is ≤Ra3.2μm by CNC turning, providing a uniform adhesion basis for the coating. The edge of the butterfly plate is rounded to avoid stress concentration of the coating.

2. Bidirectional sealing system: With EPDM or FKM soft sealing valve seat, it forms a "rigid-flexible composite" sealing interface with the HALAR coating, achieving bidirectional zero leakage at a pressure of ≤PN16 (in accordance with ISO 5208 standard).

3. ISO5211 drive adaptation: The top of the valve stem is equipped with a square shaft interface (in accordance with ISO5211 F05-F10 standard), which can be directly installed with pneumatic/electric actuators, and the torque output error is ≤5%.

Applicable media and typical scenarios

Halar coated disc butterfly valve is designed for the following media:

1. Strong acid/alkali: such as electroplating solution (containing chromic acid), wet chlorine gas in chlor-alkali process, phosphoric acid concentrate;

2. Organic solvents: petrochemical intermediates such as benzene, esters, ketones, etc.;

3. Oxidizing media: hydrogen peroxide (concentration≤50%), sodium hypochlorite solution;

4. High-purity fluid: CIP/SIP cleaning agent in the pharmaceutical industry, ultrapure water delivery.