Industrial Valves
Product range
Triple Offset Butterfly Valve
Metal seated, friction-free closing; wafer, lug and double-flanged.
View detailsHigh Performance Butterfly Valve
Double offset; RPTFE, metal and fire-safe seats; Class 150–600.
View detailsRubber-Lined Butterfly Valve
2″–60″, PN10–PN16; EPDM, NBR or FKM liner; wafer, lug and double-flanged.
View detailsButterfly valve types
Triple-offset butterfly valve
In addition to the two stem offsets, the conical seat geometry creates a third offset, so the disc contacts the seat only at the final point of closing, without rubbing. The metal-to-metal seal gives long service life in high-temperature, steam, hydrocarbon and frequently operated lines, and the metal-to-metal design suits fire-safe duty, certified by API 607 / ISO 10497 type testing. Wafer, lug and double-flanged bodies are available, with a laminated or solid seal ring. See triple-offset butterfly valves and our triple-offset selection guide.
High-performance (double-offset) butterfly valve
The stem is offset from both the disc centerline and the pipe axis, so the disc moves away from the seat quickly as it opens, reducing wear and torque. Reinforced PTFE (RPTFE) seated types are used in Class 150–300 process lines; metal-seated or fire-safe seated types serve more demanding duties. See high-performance butterfly valves.
Rubber-lined (concentric) butterfly valve
The stem passes through the center of the disc, and a flexible elastomer liner in the body provides the seal. Built in 2″–60″ (DN50–DN1500) for PN10–PN16 to API 609 Category A / EN 593 with EPDM, NBR or FKM liners, it is the common isolation valve for water, cooling water, HVAC and mild chemical lines. See rubber-lined butterfly valves.
Standards
- API 609: double-flanged, lug and wafer butterfly valves; Category B covers offset (high-performance) designs, Category A the concentric rubber-lined designs.
- EN 593: general-purpose metallic butterfly valves (rubber-lined types).
- ASME B16.34: pressure-temperature ratings.
- ASME B16.5 / B16.47: flange dimensions; check Series A or B in large sizes.
- API 607 / ISO 10497: fire type testing.
- API 598 / EN 12266-1: pressure testing.
- ISO 15848-1: fugitive emission classification.
How to choose a butterfly valve
- Temperature and leakage class: triple offset where high temperature and near-zero leakage are required; rubber-lined within the limits of the liner material.
- Unidirectional or bidirectional sealing: triple-offset valves have a preferred pressure direction; the capability in the reverse direction is stated in the offer.
- Body type: lug or double-flanged body for dead-end service.
- Flange series: ASME B16.47 Series A or B above 24″.
- Disc clearance: the disc must not contact adjacent pipe, valves or equipment (critical with wafer types).
- Operation: gear operator or actuator torque calculation; fail-safe requirement.
At a glance
| Size range | 2″ (DN50) and larger; large sizes on a project basis |
|---|---|
| Pressure class | ASME Class 150, 300, 600; higher classes for triple offset on request; PN10–PN16 for rubber-lined |
| Body type | Wafer, lug, double flanged, butt weld |
| Seat | Triple offset: metal-to-metal (laminated or solid ring); double offset: RPTFE, metal, fire-safe; rubber-lined: EPDM, NBR, FKM |
| Body / disc materials | WCB, LCC, CF8M, duplex; nickel alloys (e.g. Alloy 625) on request |
| Operation | Gear operator, pneumatic (double-acting / spring-return), electric actuator |
Butterfly valve types: catalog summary
| Type | Size | Pressure | Seat | Typical service |
|---|---|---|---|---|
| Rubber-lined concentric | 2″–60″ | PN10–PN16 | EPDM, NBR, FKM | Water, cooling water, HVAC, mild chemicals |
| High-performance (double offset) | 3″–48″ | Class 150–600 | PTFE, RPTFE, metal | Process, steam, hydrocarbons |
| Triple offset | 3″–48″ | Class 150–600 | Metal / laminated | High temperature, isolation requiring zero leakage |
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 datasheets
- PDFTriple Offset Butterfly ValvePDF · English · 1 page
- PDFHigh Performance Butterfly ValvePDF · English · 1 page
- PDFRubber-Lined Butterfly ValvePDF · English · 1 page
Key data and document numbers for all 34 series are on the industrial valve datasheets page.
Frequently Asked Questions
What is a triple-offset butterfly valve?
A butterfly valve in which the stem is offset from the center of the disc and of the pipe, and the conical seat geometry adds a third offset. The disc touches the seat only at the moment of closing, without rubbing, which gives near-zero leakage with a metal-to-metal seat, high-temperature capability and long service life.
What is the difference between double-offset and triple-offset designs?
In a double-offset valve the disc moves away from the seat as it opens but rubs slightly against it at the end of closing, so soft or reinforced seats are usually used. A triple-offset valve has no rubbing at all and uses a metal seat, which suits higher temperatures and more demanding service.
Can a butterfly valve be used for throttling?
High-performance and triple-offset butterfly valves can be used for coarse flow regulation in an opening range of approximately 20°–70°. For precise control and high pressure drop, a control valve is the better choice.
When is a rubber-lined butterfly valve the right choice?
For water, cooling water, HVAC and mild chemical lines at PN10–PN16, where a light, compact and economical valve is needed. The liner material sets the pressure and temperature limits; above them, choose a high-performance or triple-offset valve.
Related categories
Ball Valves
Floating and trunnion ball valves to API 6D / ISO 17292, API 607 fire-safe; ½”–60″, Class 150–2500.
View details
Actuated Valves
Pneumatic and electric actuated valve packages; ISO 5211, NAMUR and ATEX options; assembled and function tested.
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Special Alloy Valves
Duplex, super duplex, nickel alloy, titanium, zirconium and nickel-aluminum bronze valves for corrosive service.
View details
Cryogenic Valves
BS 6364 / ISO 28921-1 cryogenic valves down to −196 °C: extended bonnet ball, gate, globe, check and butterfly valves.
View detailsRequest a quote: Industrial Butterfly Valves
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