Gas pressure relief valve Si 6

steamfor liquidshigh-pressure

Overview
The IMI Bopp & Reuther Si 6 high-flow safety valve provides reliable overpressure protection for steam, gas and liquid systems across power, chemical and process industries. Engineered for high discharge capacity, it operates across a wide temperature range (-270°C to 550°C) and supports set pressures up to 250 barg. The solid inlet nozzle offers long-term durability; optional bellows are available to manage backpressure and improve lift control. The design features low blowdown and lift optimisation and can be configured to specific system requirements. Certified to PED and DIN/EN standards.

Key features

• Suitable for steam, gas and liquids
• Inlet sizes: DN 25 to DN 400
• Operating temperature: -270°C to 550°C
• Maximum set pressure up to 250 barg
• PN rating: PN 400
• Solid inlet nozzle for durability
• Optional bellows for backpressure management
• Low blowdown and lift optimisation
• High discharge capacity
• PED and DIN/EN certified (ASME options available)
• Customisable to system requirements

Product description
The Si 6 is a high-capacity safety valve designed for demanding industrial service. It delivers dependable overpressure protection with optimized reseating behavior and fast lift response. Available in a range of materials and flange/inlet options, the valve can be tailored to meet site-specific conditions, including corrosive fluids or elevated temperature applications. Optional bellows allow installation in systems with significant backpressure.

Specifications (summary)
Fluid types: Liquid, Gas, Vapour
Inlet size (DN): 25 to 400
PN rating (PN): 400
Maximum set pressure (barg): 250
Temperature limits (°C): -270 to 550
Max. ASME rating: 2500
Design codes: EN (ASME options available)
Certifications: PED, DIN/EN
Service category: General industrial service
Materials (EN): EN 1.0619, EN 1.7357, EN 1.4408
Materials (ASME): ASME WCB, ASME WC6, ASME CF8M

Technical specifications

• Model: Si 6 (High Flow Safety Valve)
• Suitable fluids: Liquid, Gas, Vapour
• Inlet size range: DN 25 – DN 400
• PN rating: PN 400
• Maximum set pressure: up to 250 barg
• Temperature range: -270°C to 550°C
• Max. ASME rating: 2500
• Materials (EN): EN 1.0619, EN 1.7357, EN 1.4408
• Materials (ASME): ASME WCB, ASME WC6, ASME CF8M
• Design codes: EN; ASME options available
• Certifications: PED; compliance with DIN/EN standards
• Features: solid inlet nozzle, optional bellows, low blowdown, lift optimisation, high discharge capacity
• Customization: configurable to system requirements