Valves · Butterfly Valves – Pneumatic
Pneumatic Butterfly Valve Series SSIS (BUW9 / BUL) – Pneumatic Rotary Actuator DN50–DN500
The pneumatic butterfly valve of the SSIS series switches your pipeline quickly, tight and reproducibly – actuated via a compact pneumatic rotary actuator. Available from DN50 to DN500 in double-acting (D) and single-acting (S) versions, with a disc made of stainless steel 1.4408 and flange pressure rating PN10/16. Whether new installation, retrofit or reorder of a specific size such as SSIS 500, SSIS 400 or SSIS 350 – find the right configuration here with reliable technical data.
SSIS Pneumatic Actuated Butterfly Valve DN50–DN500
Key benefits at a glance
Why the SSIS series
A complete butterfly valve series with pneumatic rotary actuator for process and utility applications – technically precise, planning-reliable and interchangeable.
DN50 to DN500 throughout
One series covering the common nominal size range for process and utility applications – including the frequently specified sizes DN300, DN350, DN400 and DN500.
Pneumatic rotary actuator, double- or single-acting
Double-acting actuators (series …-D) for control pressure 5.5…8 bar, single-acting spring-return (series …-S) for a defined fail-safe position "open" or "closed" on air failure.
Stainless steel disc 1.4408, tight shutoff
Disc in 1.4408, shaft in stainless steel, liner/seat materials to suit the medium (e.g. EPDM, FKM, R-PTFE). Media temperature up to +230 °C depending on seat variant.
Face-to-face dimensions to EN 558-1, easy installation
Wafer or lug design, face-to-face dimension to EN 558-1 R20, flange connection PN10/16 – planning-reliable and interchangeable.
Selection guide
Choosing the Right SSIS Configuration
Actuator type, material and face-to-face length determine suitability. These notes assist with sizing and exact reordering.
Actuator Type & Material
- Double-Acting (-D)
- For simple open/close switching without a defined fail-safe position, control pressure 5.5…8 bar.
- Single-Acting (-S)
- Spring return – the disc opens or closes safely on air supply failure.
- Disc
- Standard 1.4408, shaft in stainless steel (e.g. 1.4542/1.4021/1.4016).
- Liner/Seat
- EPDM (water, neutral media), FKM (oils, elevated temperature), R-PTFE (chemical/high-temperature).
Face-to-Face Length, Flange & Reordering
- Face-to-Face Length
- To EN 558-1 R20 – verify the installed face-to-face length of the existing valve for drop-in replacement compatibility.
- Flange
- Flange pressure rating PN10/16, wafer or lug style.
- Part number
- Encodes series, nominal size, material and actuator variant (e.g. BUL2A-100-SSRS-S12 = DN100, single-acting).
- Control pressure
- Consistently 5.5…8 bar for all actuator variants.
Drive variants compared
Double-acting (D) vs. single-acting (S)
The SSIS family offers both actuation concepts. The choice depends on the required behavior upon loss of air supply.
| Double-acting (-D) | Single-acting (-S) | |
|---|---|---|
| Actuation | Air pressure on both sides | Air pressure + spring return |
| Behaviour on air failure | Stays in last position | Defined fail-safe position open/closed |
| Control pressure | 5.5…8 bar | 5.5…8 bar |
| Typical application | Pure on/off switching | Emergency stop / safety function |
| ATEX variant | Available with suffix "-A" | Available with suffix "-A" |
Series & Variants
SSIS and BUL Series Overview
The right butterfly valve for your application – from double-acting and ATEX to the double-eccentric BUL line.
Application Areas
Applications of the SSIS butterfly valve
Material and seat variants of the SSIS and BUL family cover a wide range of media.
Water & Wastewater
Epoxy-coated body, EPDM liner, medium water – variants with DVGW approval available (documented in the BUA series).
Chemical & Process Engineering
Liner/seat material FKM or R-PTFE for aggressive or high-temperature media up to +230 °C.
Abrasive Media (Sand, Cement)
Special versions with EN-GJS-400-15 body and carboxylated NBR liner (BULI/BULB series).
HVAC & Ventilation / Utilities
Fast, tight shut-off of large nominal sizes up to DN500 via compact pneumatic rotary actuator.
Hygienic Utility Circuits
1.4408 stainless steel disc with EPDM liner for neutral media in utility and clean water circuits.
Plant & Vessel Construction
Drop-in face-to-face dimension per EN 558-1 R20 and PN10/16 flange for retrofitting and replacement.
Availability & Shipping
Procurement via STASTO Automation
Configured standard variants and EU-wide shipping – live stock levels displayed directly in the shop.
Common sizes available short-term
Standard variants from DN50 to DN300 are available for short-term delivery depending on configuration – current stock is shown live in the shop.
EU-wide shipping
Delivery via STASTO Automation throughout the EU.
Verified materials
Body materials such as EN-GJS-400-15 and 1.0625, face-to-face dimensions to EN 558-1 – country of origin available on request depending on series.
Project-specific configuration
Nominal size, actuator type and material can be precisely matched to your project requirements.
Frequently Asked Questions
FAQ – SSIS butterfly valve
Answers on nominal sizes, actuator types, standards and variants of the SSIS series.
Which nominal sizes does the SSIS series cover?
The SSIS series covers DN50 to DN500 throughout. Included are frequently requested sizes such as DN80, DN125, DN150, DN300, DN350, DN400 and DN500.
Double-acting or spring return – what does STASTO supply?
STASTO supplies both: double-acting actuators (-D) and single-acting with spring return (-S). Both operate at a control pressure of 5.5…8 bar.
What flange pressure rating and face-to-face dimension?
The flange connection is rated for PN10/16, and the face-to-face dimension complies with EN 558-1 R20. Available as wafer or lugged design.
Is an ATEX version available?
Yes, the SSIS butterfly valve is available as an ATEX variant with the suffix "-A" (e.g. BUW9-SSIS-D-A) for use in potentially explosive atmospheres.
Are material certificates available?
Material certificates, e.g. 3.1 per EN 10204, are available on a project-specific basis. Please indicate your requirement when submitting your enquiry.
Are matching manual variants available?
Yes, complementary versions with hand lever, gearbox operator or bare shaft end for custom actuator mounting are available.
What media temperature is possible?
Depending on the seat variant, media temperatures up to +230 °C are possible. The decisive factors are the liner and seat materials such as EPDM, FKM or R-PTFE.
Related categories
Related and adjacent valve types
Complementary categories from the STASTO range of automatic and manual shut-off valves.
Configure now
Configure your SSIS butterfly valve now
Select nominal size (DN50–DN500), actuator type and material – or request the datasheet for your desired size. Our engineering team is available to assist with sizing.