Visilume is Now Employee Owned

Visilume Limited is proud to announce that as of 1st October 2014, it is now an employee owned company
Having remained an independent company since it was founded in 1984; Visilume has built up a strong UK and International customer base by prioritising customer service and providing easy access to technical expertise.
By transferring a controlling stake of the company to employees, we have created a structure that will secure the long-term future of the company, and the core objectives of continued independence and customer service.
The transition to employee ownership is occurring with the company in the strongest position it has ever been and this move increases the involvement of the people who have contributed so much to its success. Please note that there is no change to the management structure.
As this exciting new phase unfolds, we would like to thank you for your ongoing support and look forward to many more years of mutually beneficial trading.

Visilume’s Range of Sight Glasses

Visilume supplies a wide range of sight glasses for viewing the contents and also the level of tanks, vessels or pipelines. Sight glasses allow you to monitor liquid flow either manually or at a distance. Sight glasses can be installed by welding, bolting or clamping into your equipment. Sight glasses are assembled to suit the needs of your specific plant and vary in pressure from high vacuum through atmospheric to high pressures up to 1000 bar. There is a very wide range of applications so there are sight glasses suitable for each application from cryogenic through to furnaces. Sight glasses can be as small as 6mm and as large as 600mm. Site glass surrounds are made of diverse materials to suit your process, these include aluminums, carbon steels, stainless steels, duplex stainless steels and hasteloys.
We have a wide range of sight glasses to suit different processes and environments:
  • Circular sight glasses for viewing the contents of a tank or pressure vessel.
  • Metaglas sight windows which have unmatched strength and offer the ultimate solution for operator and process safety.
  • Glass tube liquid level gauges to view the contents of a tank or pressure vessel.
  • Rectangular site glass fittings to view the level and contents of a tank or pressure vessel.
  • Transparent level gauges to view the contents of a pressure vessel.
  • Sanitary and hygienic equipment.
  • Water treatment sight window fittings

These are now described in more detail


Circular Sight Glass Fittings to DIN 28120

These are weld-on site glass fittings for the observation of the internals of pressure vessels, silos, gear trains, separators, pipelines etc. These fittings are circular flanged sets suitable for welding into or onto vessel walls, complete with seals and site glass disc set between the flange rings. They can be combined with Lumiglas light fittings for use in explosion hazardous areas and safe areas.

Sight Flow Indicators

These are used to check for presence of a fluid. They can be used in vertical or horizontal lines. The integral drip lip makes them ideal for leak detection. They have a high quality robust design, are CE marked and fully compliant with the pressure equipment directive. Connections can be flanged or threaded. They cover pressures up to 100 bar and temperatures up to 250°C.

Metaglas Sight Glasses

Metaglas sight glasses are the strongest and most secure glass for sight window applications. The mechanically pre-stressed glass fused to metal construction provides levels of safety and length of service far beyond that offered by any conventional sight glasses.

Glass Tube Liquid Level Gauge

The glass tube indicator is for installation in condensation tanks, reservoirs, fire sprinkler tanks, water supply tanks. The level guage may be equipped with automatic closing ball, which closes in the case of glass breakage.

Rectangular Sight Glass Fittings

These site glass fittings are mainly used as fluid level indicators for vessels, silos, and reactors.

Transparent Level Gauge

These sight glasses are ideal for steam boiler applications. They can operate in pressures up to 250 bar and 450°C. They are designed for either direct viewing or CCTV transmission to a central room.

Reflection Level Gauge

The reflection level gauge is ideal for steam boiler applications up to 35 bar and 243°C. They can also be used in refrigeration plants, chemical storage vessels, condensate tanks and reservoirs for mineral and vegetable oils. They provide a direct indication of water level using distinctive dark and light areas.

Sanitary and Hygienic Equipment

The Metaglas sanitary Metaclamp is of extremely robust construction. It is suitable for food processing and pharmaceutical applications. It has extreme resistance to impact and safeguards against total failure of the process. It is widely accepted in the European and American food, beverage, pharmaceutical and chemical industries.

Water treatment

Sight ports are custom built for process observation in the water treatment and allied industries. There is a range of standard or special sight ports with viewing diameters from 100 mm to 600 mm. They are suitable for setting into concrete, bolting onto a base flange or welding into steel vessels and tanks.


We have sight glasses for every process carefully matched to the specifics of your process by our technical experts.

Contact us now

Visilume Ltd | High Street West | Glossop | SK13 8ER | United Kingdom
Tel: +44 (0) 1457 865 700 | Fax: +44 (0) 1457 865 770 | E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
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