Butterfly Valves for Water, Gas and Chemical Applications: Media Compatibility Guide

Different media demand different materials. A valve that works for chilled water may fail quickly on chemical or gas lines. This guide provides direct selection tables for water, gas, and chemical applications.

Quick Selection Matrix by Media

Media Category	Recommended Body	Recommended Disc	Recommended Seat
Fresh / Chilled Water	Ductile Iron	Epoxy-coated DI	EPDM
Sea / Brackish Water	Ductile Iron / SS316	SS316	EPDM / Viton
Hot Water (80-120°C)	Ductile Iron	SS304	EPDM
Low Pressure Steam	Cast Steel	SS304	PTFE / Graphite
Natural Gas / LPG	Ductile Iron	SS304 / Aluminum Bronze	NBR / Viton
Compressed Air	Ductile Iron	Epoxy-coated DI	NBR
Mild Acids (pH 3-6)	SS316	SS316	Viton / PTFE
Strong Acids (pH <3)	PTFE-lined	PTFE-coated	PTFE
Caustics / Alkalis	SS316 / Ductile Iron	SS316	EPDM / Viton
Solvents	SS316	SS316	Viton / PTFE
Oils / Hydrocarbons	Cast Iron / Steel	SS304	NBR / Viton

Water Applications

Water Type	Key Challenge	Recommended Seat	Recommended Disc
Potable Water	NSF certification	EPDM (NSF)	Epoxy-coated
Chilled Water	Low temperature	EPDM	Epoxy-coated
Cooling Tower	Aeration, biological growth	EPDM / Viton	SS304+
Sea Water	Chloride corrosion	EPDM	SS316 (CF8M)
Wastewater	Abrasive solids	EPDM	Epoxy-coated + SS edge

Gas Applications

Gas Type	Key Safety Concern	Recommended Seat	Disc Material
Natural Gas	Flammability	NBR / Viton	SS304
LPG / Propane	High pressure	NBR	SS304
Compressed Air	Pressure spikes	NBR	Epoxy-coated DI
Oxygen	Combustion hazard	PTFE (degreased)	SS316
Biogas	Corrosive H2S	Viton	SS316

Warning for Oxygen Service: Use only degreased, oil-free valves with PTFE seats. Standard valves will ignite.

Chemical Compatibility – Seat Materials

Seat Material	Water	Steam	Acids	Caustics	Solvents	Oils	Gas
EPDM	A	C	D	A	D	D	B
NBR	A	D	D	C	C	A	A
Viton	A	B	B	D	B	A	A
PTFE	A	A	A	A	A	A	A

Rating: A=Excellent / B=Good / C=Fair / D=Poor (Do not use)

End Connection by Application

Media	Wafer	Lug	Flanged
Water (closed loop)	Yes	Optional	No
Water (dead-end)	No	Yes	Yes
Gas	Yes	Optional	Rare
Chemical	No (lined unavailable)	No	Yes

Common Mistakes to Avoid

Mistake	Consequence	Correct Practice
EPDM seat with solvents	Seat swells, valve locks	Use Viton or PTFE
SS304 disc in seawater	Pitting corrosion	Use SS316
Wafer valve at dead-end line	Disc damage, leakage	Use lug or flanged
No grounding for natural gas	Static spark risk	Install anti-static device

Summary Selection Checklist

Before specifying, confirm:

Media – exact fluid and concentration
Temperature – min, max, peak
Pressure – operating and shut-off
End connection – wafer, lug, or flanged

Contact our team for verified compatibility recommendations.

Ivan (Mobile:+86-18968769287)
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ZHEJIANG KINKO FLUID EQUIPMENT CO.,LTD