Primary Flowpoints Ltd

Primary Flowpoints Ltd

Primary Flowpoints Ltd, Charles Street, Walsall, WS2 9LZ. UK

Style F Sight Flow Indicator

Style F Sight Flow Indicator


With the flap and easy to read scale the style F sight flow indicator is used to check the flow rate of a liquid in a pipeline. It can be used in vertical or horizontal lines and is ideal as a plant safety device where you need to maintain a constant flow, for example in lubricating or cooling systems.


The standard bodies are cast in either; carbon steel, 316 stainless steel or LG2 gun metal, though we can produce them in other materials.

The glass windows are held in place by stainless steel covers and screws, and sealed with PTFE gaskets, giving superior protection. For ease of maintenance the glasses can be individually removed and replaced.

For standard applications the indicator is fitted with toughened soda lime glass discs to BS3463 and rated to 16 bar.

For steam and condensate we recommend toughened borosilicate glass, while for alkaline liquids mica discs can be used to protect the glass.

The sight glasses can be supplied with screwed connections to NPT, BSP parallel or taper. The standard flanges available are ANSI 150, ANSI 300 and PN16, though special flanges can be machined.



Primary Flowpoints stock carbon, stainless steel and gun metal, but can supply sight glasses in special materials such as super duplex, hastelloy or low carbon steels. For particularly corrosive applications the body can be lined with PFA.


High pressure toughened soda lime to BS3463 rated to 40 bar 60 bar depending on size, toughened borosilicate to BS3463 or DIN7080 rated up to 16 bar. Higher pressures are available by reducing the viewing diameter. The high pressure range uses powder coated mild steel covers as standard, though stainless steel covers are available.


For high flow rates and vertical lines the flap can be spring loaded. This option will give three times the normal flow range.


Graphite gaskets are available if required.


We can also offer A4 stainless steel fasteners when necessary.


All Flowpoints indicators are manufactured to the highest standards.

The quality system is independently audited by BSI and certified to ISO 9001. The indicators are fully PED compliant and CE marked where required. TUV are our external auditors for the Pressure Equipment Directive.

Full material traceability is maintained, material certificates and pressure test certificates are supplied on request.

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