The Schwer Fittings A-4BVG is a manual 4-way ball valve designed for directional gas flow control in industrial piping circuits. The body and ball are machined from 1.4408 (AISI 316) stainless steel investment casting, providing corrosion resistance suitable for aggressive industrial gas environments. PTFE seats and seals ensure tight shut-off and low operating torque across the full size range from DN8 to DN50. Each valve includes an ISO 5211 top flange for mounting pneumatic or electric actuators, enabling field conversion from manual to automated operation.

How does a 4-way ball valve control gas flow?

A 4-way ball valve uses a bored ball with an X-shaped or L-shaped passage pattern. In the standard X-port configuration, rotating the lever 90° redirects the gas stream between two pairs of ports — switching the flow path without interrupting supply. An L-port ball (available on request) connects the inlet to one of two outlets while blocking the opposite port, functioning as a diverter. The A-4BVG is rated for on-off gas service up to 64 bar, with the PTFE seals providing low-friction operation and bubble-tight shut-off. The 90° handle position gives the operator immediate visual confirmation of flow direction.

What makes a ball valve suitable for gas service?

Gas-rated ball valves differ from general-purpose models in seal design and material certification. The A-4BVG uses PTFE seals, which offer wide chemical compatibility and do not absorb moisture — critical for maintaining seal integrity in dry gas service. The 1.4408 stainless steel body resists corrosion from trace moisture or reactive gas components that would attack carbon steel. Under the European Pressure Equipment Directive (PED 2014/68/EU), Schwer advises that 4-way valves above DN25 used with hazardous (Group 1) fluids require a technical compliance review. For standard industrial gases (Group 2), the valve is approved across its full DN8–DN50 range up to 64 bar. An anti-blowout stem design and fire-safe certified variants are available within the A-4BV product family.