Sight Glass Indicators - Machined - GM | BLU ZAC

BLU ZAC GM Machined – Double-Sided Flow Indicator

The BLU ZAC GM is a double-sided flow indicator with a fully machined body from a single piece. It is used for visual flow inspection of liquids or gases in small to medium diameter pipelines, with the option to integrate static or mobile indication elements.

Technical Specifications

• Sizes: 3/8" to 4"
• Connections: butt weld per ANSI B16.25 or flanges per ANSI B16.5
• Flanged versions: 150 RF / 300 RF, according to dimension table
• Glass: tempered borosilicate per DIN 7080
• Glass arrangement: one or two glasses per side
• Glass limit: 51 bar, 280 °C
• Gaskets: graphite
• Body/Cover Materials: ASTM A105, A350 LF2, A182 F304, F316, F304L, F316L, F11 Cl.2, F22 Cl.3, F44, F51, F53

Indication Versions

The GM can be delivered as:

• Type X: without internal indicator
• Type Y: lug
• Type Z: ball
• Type W: rotor
• Type K: pipe
• Type V: check valve

Selection depends on fluid transparency, flow velocity, installation direction, and the need for visual confirmation under low contrast conditions.

Application Scope

Typical applications include steam mains, tracing lines, turbine lines, marine installations, presses, and auxiliary process networks. The final permissible operating limit is determined not only by the body material per ASME B16.34 but also by the glass, diameter, temperature, and connection type.

Difference from GC / GF / GW

The GM differs from cast, forged, or welded series as the body is machined from a solid piece. It is selected when project specifications require specific ASTM materials, smaller dimensions, and BW or ANSI flange connection in a compact machined construction.

Maintenance

Isolation, venting, and hazardous residue checks are required before disassembly. During maintenance, the glass is inspected for wear, and graphite gaskets are replaced before restarting.