When should I specify a Triple Offset (TOV) valve instead of a Double Offset (DOV)?

Use TOV when your application requires bubble-tight shutoff at temperatures above 150–200°C or involves high-pressure, abrasive, or particulate-laden media where resilient seals are unsuitable. TOV provides metal-to-metal sealing up to 550°C.

Can Krombach large bore valves be used for seawater applications?

Yes. A hard-rubber lined version is available specifically for seawater service. The rubber lining specification is selected based on application requirements.

What actuation options are available for these valves?

Krombach valves feature an ISO 5211 top mounting flange, compatible with manual gearboxes, electric actuators, hydraulic actuators, and pneumatic actuators. Complete mounting-ready actuator packages are available.

Are in-line repairs possible without removing the valve from the pipeline?

Yes. The single or bidirectional locking device secures the disc in position during maintenance, enabling safe in-line seat and seal replacement.

What standards do these valves comply with for flange connections and face-to-face dimensions?

Flanged connections comply with DIN EN 1092-1, ASME B16.47-RF, and AWWA C207. Face-to-face dimensions meet DIN EN 558-1 R14, ASME B16

CRANE CHEMPHARMA & ENERGY · BUTTERFLY VALVES

Krombach Large Bore Double Offset and Triple Offset Butterfly Valves DN700-DN3400

Name: Krombach Large Bore Double Offset and Triple Offset Butterfly Valves DN700-DN3400
Brand: Crane ChemPharma & Energy

Krombach DOV & TOV large bore butterfly valves by Crane for power, water & industrial applications. DN700-DN3400, up to 550°C.

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Overview

Krombach® large bore butterfly valves from Crane ChemPharma & Energy are engineered for critical isolation duties in power generation, water treatment, and heavy industrial applications. Available in Double Offset (DOV/AK120) and Triple Offset (TOV/AK110) configurations, these valves cover sizes from DN700 (28") up to DN3400 (136"), addressing the needs of large-diameter piping systems.

The Double Offset design features an eccentric disc movement where the shaft is offset from both the bore centerline and the disc seat centerline. This reduces seat-to-seal friction to only the first and last 10 degrees of travel, extending service life in applications up to 200°C with resilient seating materials (EPDM, NBR, FKM).

For higher temperatures or applications demanding bubble-tight metal-to-metal shutoff, the Triple Offset design adds a third geometric offset—a right-angle conical seat profile. This ensures near-frictionless 90° operation with contact only at final closure, making TOV valves suitable for temperatures up to 550°C (1100°F) and volatile or particulate-laden media.

Key Features

Double Offset (DOV): Rubber-lined sealing element on disc for reduced friction and extended seal life
Triple Offset (TOV): Metal-seated, torque-generated sealing for bubble-tight shutoff at extreme temperatures
Single or bidirectional locking device: Secures disc position during maintenance for safe in-line repair
Welded body design: Meets DIN, ANSI/ASME, and AWWA standards for flexibility in face-to-face dimensions and pressure ratings
ISO 5211 top mounting flange: Compatible with manual gear, electric, hydraulic, and pneumatic actuators
Replaceable seat retainer ring: Simplifies maintenance and allows sealing element adjustment
Optional electric heat tracing/jacket: Prevents freezing in low-temperature environments
Hard-rubber lined version: Available for seawater and corrosive media applications

Specifications

DN (mm)	NPS (inch)	2.5 bar (36 psi)	6 bar (90 psi)	10 bar (150 psi)	16 bar (200 psi)	25 bar (350 psi)
700	28	✓	✓	✓	✓	✓
800	32	✓	✓	✓	✓	✓
1000	40	✓	✓	✓	✓	✓
1200	48	✓	✓	✓	✓	–
1600	64	✓	✓	✓	–	–
2000	80	✓	✓	–	–	–
2400	96	✓	✓	–	–	–
3000	120	✓	✓	–	–	–
3400	136	✓	✓	–	–	–
Component	DIN EN Material No.	ASME Grade
Body	1.0038	A283 (C)
Disc	1.0038	A283 (C)
Retainer Ring	1.0038	A283 (C)
Sealing Element	EPDM / NBR / FKM	EPDM / NBR / FKM
Body Seat	1.4301	A479 (304)
Shaft	1.4021	A276 (420)
Shaft Sealing	NBR / FKM	NBR / FKM
Bushing	Bronze / PTFE-sinter	Bronze / PTFE-sinter
Sealing Material	Temperature Range
EPDM	-18°C to 104°C (0°F to 220°F)
NBR	-10°C to 80°C (14°F to 180°F)
FKM	-20°C to 200°C (-4°F to 392°F)
Parameter	Standards
Flanged Connections	DIN EN 1092-1, ASME B16.47-RF, AWWA C207
Face-to-Face Dimensions	DIN EN 558-1 R14, ASME B16.10, AWWA C504
Buttweld Ends	Krombach design or customer specification

Applications

- Power plants: Cooling water cycle isolation, steam and condensate systems - Water & wastewater: Drinking water pump stations, desalination plants, seawater intake - Oil & gas: Process isolation in refineries and petrochemical facilities - General industry: Large-diameter pipeline isolation in chemical plants, steel mills, and paper mills