FKM Seat Butterfly Valve

FKM Seat butterfly valve in industrial-grade valve manufacturing systems, fluorocarbon elastomer (designated FKM according to ASTM D1418) has become the preferred engineering material for dynamic sealing interfaces due to its unique molecular structure. This polymer maintains ASTM D2000 M6EE907 certification for chemical inertness within a working temperature range of -18°C to 150°C (in FKM seat butterfly valve).

The core advantages of FKM materials

1. Fluoroelastomer (FKM) is a fluorine-containing synthetic elastomer that is used as a seat material for FKM seat butterfly valve, and its properties include:

2. Chemical resistance: Resistant to strong acids (such as 98% sulfuric acid, 37% hydrochloric acid), strong alkalis (50% NaOH), hydrocarbon solvents and ozone, and the corrosion resistance level is better than NBR/EPDM;

3. High temperature adaptability: continuous working temperature range -20°C~180°C, short-term resistance to 200°C thermal shock (This is only for pure rubber, when used for butterfly valve seats are usually the maximum temperature is 150°);

4. Low permeability: the gas permeability is only 1/5 of NBR, which prevents the expansion and failure of the valve seat caused by medium penetration;

5. Mechanical stability: hardness range 70~90 Shore A, compression set rate≤15% (ASTM D395 test).

6. The seat life of FKM seat butterfly valve can reach 8~12 years, which is more than 3 times that of ordinary rubber valve seats

Typical application scenarios：

1. Organic solvents: acetone, xylene, carbon tetrachloride;Oxidizing medium: hydrogen peroxide (concentration ≤30%), sodium hypochlorite solution

2. Highly corrosive fluids: electroplating solution, mixed acid (aqua regia), wet chlorine gas in chlor-alkali process

TECHNICAL SPECIFICATION TABLE – FKM Seat Butterfly Valve

CORE ADVANTAGES

For demanding chemical applications, we offer unique value through our two production bases (Tianjin & Wenzhou) and integrated supply chain:

1. Weather Resistance & Extended Lifespan: Using high-fluorine-content raw rubber, our FKM seats maintain low compression set even under frequent switching and alternating acid/alkali media. Actual service life reaches 8–12 years — over 3 times that of ordinary rubber seats, significantly reducing replacement frequency and maintenance costs.

2. North-South Supply Chain Integration: For large-diameter (DN300+) carbon steel bodies, we rely on our Northern (Tianjin) foundry; for stainless steel and special alloy bodies, our Southern (Wenzhou) finishing center handles precision machining. This layout ensures competitive lead times and cost efficiency.

3. Full-Process Quality Inspection: Every FKM seat butterfly valve undergoes 100% shell strength testing (1.5× rated pressure) and 100% low-pressure pneumatic leak testing (0.6 MPa) before shipment — eliminating both external and internal leakage.

4. Precision Curing Process: FKM seat vulcanization directly affects corrosion resistance. We use precision temperature-controlled flat vulcanization presses to strictly control crosslink density, ensuring consistent hardness and resilience across all batches — preventing media penetration and blistering caused by uneven curing.

5. Global Project Certifications: Products can be supplied with ISO 15848-1 (low emissions) for VOC control and API 607 / ISO 10497 (fire-safe) optional certifications — meeting the qualification requirements for high-end chemical projects in Europe, America, and the Middle East.

FREQUENTLY ASKED QUESTIONS (FAQ)

Q1: How do I choose between FKM, EPDM, and NBR seats in terms of price and performance?

A: If your media is water, air, or mild acids/alkalis, EPDM is cost-effective and sufficient. However, if your application involves petroleum hydrocarbons, aromatic solvents (e.g., xylene), concentrated acids, or temperatures above 100°C, FKM is strongly recommended. Although FKM costs more than EPDM, its superior solvent resistance and high-temperature stability are irreplaceable in harsh conditions, ultimately saving maintenance costs over the long term.

Q2: Is the FKM seat molded-in or replaceable? Is replacement easy?

A: We offer both integral molded-in (vulcanized to the body) and replaceable (field-serviceable) seat designs. For large-diameter chemical valves, we recommend the replaceable seat (usually liner or U-seat type). When the sealing surface wears out, you can replace the seat without removing the entire valve from the pipeline — significantly reducing plant downtime. Just inform us of your operating conditions, and our technical team will recommend the optimal configuration.

Q3: Is your FKM butterfly valve suitable for "wet chlorine gas" or "high-temperature steam" service?

A:

• For wet chlorine: Our specially formulated high-fluorine FKM seat offers excellent water resistance and chloride ion resistance — a classic choice for the chlor-alkali industry. However, ensure the temperature remains below 120°C and the chlorine does not contain excessive free water.

• For high-temperature steam: Please note — FKM is NOT recommended for continuous saturated steam service (steam can break the vulcanization bonds). If your process involves frequent steam purging, we recommend our PTFE-lined butterfly valve, which offers superior temperature resistance and hydrolysis resistance.

Q4: My required size is DN1800, which exceeds your standard list. Can you produce it?

A: Absolutely. Although our standard range is DN40–DN1600, Zhongguan Valve has large-diameter non-standard customization capabilities. We have previously manufactured FKM seat butterfly valves up to DN2000 for major chemical plants. Simply provide your specific media composition, temperature, and connection dimensions, and our engineers will perform FEA (Finite Element Analysis) design and schedule production accordingly.

Q5: What is the shipping time to overseas destinations (e.g., Oceania or Europe)? What about after-sales support?

A: For small-batch orders, sea freight to major ports (e.g., Sydney, Melbourne) takes approximately 18–22 days after production completion. We provide export-certified fumigated wooden crates and neutral / private-label packaging options.

After-Sales Service:

• We offer an 18-month warranty (excluding misuse or out-of-spec operating conditions).

• Remote video installation guidance is available.

• In case of quality issues, we commit to unconditional replacement of faulty parts or negotiation of return/refund.