What is the difference between wafer and lug butterfly valves?

A wafer butterfly valve is sandwiched between two pipe flanges with long through-bolts. A lug valve has threaded inserts, so each flange bolts independently and one side can be removed without draining the line.

When should I use a lug butterfly valve?

Use a lug valve for dead-end service, tank isolation, or anywhere you need to remove one side of the pipe without shutting down the other side.

When should I use a flanged butterfly valve?

Use a flanged (double-flanged) butterfly valve for large sizes, higher pressures, buried service or where the valve must support significant pipe loads.

Which is cheaper: wafer or lug butterfly valve?

Wafer valves are typically the most economical because they are lighter and use fewer materials. Lug valves cost more due to the threaded inserts, and flanged valves cost the most.

Wafer vs Lug vs Flanged Butterfly Valve: An RFQ Decision Guide

If you're preparing a butterfly valve RFQ, one of the first choices is the end connection: wafer, lug or flanged. It affects price, installation, maintenance and whether the valve can serve a dead-end line.

Here's the plain-English comparison, plus a checklist to make the call fast.

Wafer Butterfly Valve

A wafer valve is sandwiched between two pipe flanges. Long through-bolts pass through the pipe flanges and the valve body together. It is the lightest and most economical option.

Best for: general isolation, HVAC, water lines, non-critical service
Pro: lowest cost, lightest weight, smallest face-to-face
Con: cannot be used for dead-end service — removing the downstream flange leaves the valve unsupported
Typical range: DN50–DN1200, PN10/PN16

Lug Butterfly Valve

A lug valve has threaded inserts (lugs) on the body. Each pipe flange bolts to the valve independently.

Best for: dead-end service, tank isolation, equipment isolation, fire protection
Pro: one side can be disconnected while the other stays sealed — no need to drain the line
Con: costs more than wafer due to the inserts
Typical range: DN50–DN1200, PN10/PN16

Flanged (Double-Flanged) Butterfly Valve

A flanged valve has integral flanges cast onto the body, matching standard pipe flanges.

Best for: large sizes, higher pressure, buried service, high-vibration or high pipe-load applications
Pro: strongest connection, supports pipe loads, easy to align
Con: heaviest and most expensive
Typical range: DN50–DN2000, PN10–PN40

Comparison at a Glance

Aspect	Wafer	Lug	Flanged
Cost	Lowest	Medium	Highest
Weight	Lightest	Medium	Heaviest
Dead-end service	No	Yes	Yes
Pipe load support	Minimal	Moderate	Full
Maintenance	Needs line drain	Isolate one side	Isolate one side
Typical size	DN50–DN1200	DN50–DN1200	DN50–DN2000

RFQ Decision Checklist

Is dead-end service required? Yes → lug or flanged. No → wafer is fine.
Large size or high pressure? DN300+ or PN25+ → flanged.
Buried or high-vibration line? → flanged.
Budget priority? → wafer.
Will one side need isolation during maintenance? → lug.

Ready to source? Reguvale manufactures wafer, lug and flanged butterfly valves in DN50–DN1200 (wafer/lug) and up to DN2000 (flanged), in ductile iron, carbon steel and stainless steel — with stock lead times of 5–7 days. Send us your RFQ and we’ll confirm the right connection type for your line.