DN300 FKM/PTFE Rubber Expansion Joint with Gr5 Titanium Flanges for Sulfuric Acid Service
Product Overview
This product is a DN300 single-arch, hand-built rubber expansion joint featuring a 335mm face-to-face length.
The core construction utilizes an integrated fluoroelastomer (FKM) inner and outer matrix, combined with a vulcanized, full-face sealing polytetrafluoroethylene (PTFE) liner. The connection components consist of Grade 5 (Ti-6Al-4V) titanium alloy flanges and integrated control unit ear plates.
This specific material and structural synthesis solves the industry pain points of media permeation, rubber matrix swelling, and galvanic corrosion of metallic flanges when generic flexible joints are exposed to high operating pressures alongside severe chemical attack.
The assembly is custom-configured for copper refining liquid (predominantly sulfuric acid electrolyte). At a steady operating temperature of 27°C, it maintains mechanical integrity under a high working pressure of 2.5MPa, isolating high-frequency vibrations from pumps and valves while providing reliable containment under the specified operating conditions.
Key Features
- Full-Face PTFE Liner Protection: The PTFE liner extends completely over the rubber sealing face to the outer edge of the flange. This creates a continuous physical barrier, isolating the rubber body from fluid contact and reducing chemical attack on the rubber structure.
- Hand-Built Solid Construction: Built manually via a layer-by-layer wrapping process. This method delivers uniform distribution of heavy-duty fabric reinforcement, preventing structural ballooning under 2.5MPa pressure.
- Gr5 Titanium Flanges & Lug Plates: Flanges and tie-rod ear plates are machined from Gr5 titanium alloy. This material maintains near-zero corrosion rates in acidic solutions containing copper ions, provides excellent corrosion resistance in acidic environments.
- FKM Matrix Compounding: Both inner and outer rubber plies consist of FKM rubber compound, providing an extra boundary of resistance to acid mist, atmospheric ozone, and process chemical splashes.
- SS304 Tie Rod Limitation: Equipped with SS304 stainless steel control rods. This assembly restricts excessive axial extension under high hydraulic thrust (2.5MPa), shielding adjacent piping anchors.
Applications
- Copper refining electrolyte circulation piping
- Sulfuric acid transfer lines
- Acid process piping systems
- Chemical plant pump and valve connections
Engineering-FAQ
Why is a PTFE liner combined with FKM rubber for sulfuric acid service?
Answer:
- PTFE liner provides a chemical-resistant barrier between the process medium and rubber body.
- FKM rubber provides flexibility and structural support for the expansion joint.
- The titanium flange configuration improves corrosion resistance at the connection area.
- Actual chemical compatibility should be verified according to acid concentration, temperature and operating conditions.
