Industrial Butterfly Valves
In a rubber-lined (concentric) butterfly valve, the stem passes through the center of the disc and sealing is provided by a flexible rubber liner covering the body. Light, compact and economical, it is the usual isolation valve for water, cooling water, seawater, HVAC and low-pressure process lines.
Overview
The liner material is selected for the fluid: EPDM for water and hot water, NBR for oils and hydrocarbons, FKM for chemicals and higher temperatures. The disc is ductile iron (coated), stainless steel (CF8, CF8M) or, for seawater lines, nickel aluminum bronze. Because the liner grips the disc tightly in both directions, the valve can be used bidirectionally.
The wafer type is clamped between two flanges and is the economical choice; the lug type, with threaded lugs on the body, can also be used in end-of-line (dead-end) service; in large sizes a double-flanged body is preferred. Pressure and temperature limits are set by the liner material; for higher pressures and temperatures, select a high performance or triple offset butterfly valve.
Technical specifications
| Size | 2″–60″ (DN50–DN1500); larger sizes on a project basis |
|---|---|
| Pressure | PN10–PN16 (145–232 psi) |
| Body type | Wafer, lug, double-flanged |
| Design | API 609 Category A, EN 593 |
| Liner (seat) | EPDM, NBR, FKM; PTFE-lined on request |
| Disc | Ductile iron (coated), CF8, CF8M, aluminum bronze |
| Flange compatibility | EN 1092-1 PN10 / PN16, ASME B16.5 Class 150 |
| Operation | Notched lever, gear operator, bare stem, pneumatic or electric actuator (ISO 5211) |
Key features
- Light and compact: easy installation in tight spaces
- Bidirectional rubber liner
- Lever, gear and actuator options; ISO 5211 mounting pad
- Aluminum bronze disc option for seawater
- Cost-effective isolation in large sizes
Catalog data
| Size and pressure | 2″–60″ (DN50–DN1500), larger sizes on a project basis; PN10–PN16 (145–232 psi) |
|---|---|
| Body type | Wafer, lug, double flanged |
| Design | API 609 Category A / EN 593 |
| Seat (rubber liner) | EPDM, NBR, FKM; PTFE-lined on request |
| Disc | Ductile iron (coated), CF8, CF8M, aluminum bronze |
| Operation | Notched lever, gear operator, bare stem, pneumatic or electric actuator |
Documentation and testing
On industrial projects the documentation package matters as much as the valve. We confirm the certificate and test scope for every line item at quotation stage:
- EN 10204 3.1 material certificates for pressure-retaining and wetted parts, traceable by heat number
- EN 10204 3.2 with third-party inspection, on request
- Pressure test reports to API 598 or EN 12266-1: shell, seat and, where specified, gas tests
- Fire-test certificates (API 607 / ISO 10497) for fire-safe type-tested designs
- PMI reports for alloy and stainless materials
- Dimensional, visual and coating inspection records
- PED 2014/68/EU CE declaration for equipment within its scope
- NACE MR0175 / ISO 15156 compliance statement for sour (H₂S) service
Technical datasheet
Frequently Asked Questions
What temperature can a rubber-lined butterfly valve handle?
The liner material sets the limit: EPDM approximately −20 °C to +120 °C (−4 °F to +248 °F) for water and hot water, NBR approximately −10 °C to +80 °C (+14 °F to +176 °F) for oils and hydrocarbons, FKM up to approximately +150 °C (+302 °F) for chemicals, depending on the fluid. For higher temperatures and pressures, select a high performance or triple offset butterfly valve.
What is the difference between wafer and lug types?
The wafer type is clamped between two flanges with studs and is the economical choice. The lug type has threaded lugs on the body; even if one side of the line is removed, the valve stays bolted to the other flange and can be used in end-of-line (dead-end) service.
Related products
Triple Offset Butterfly Valve
Metal seated, friction-free closing; wafer, lug and double-flanged.
View details
High Performance Butterfly Valve
Double offset; RPTFE, metal and fire-safe seats; Class 150–600.
View detailsRequest a quote: Rubber-Lined Butterfly Valve
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