How to choose a sight glass for a vessel: 10 input parameters
A checklist of input data: task, mounting, geometry, pressure, temperature, medium, materials, lighting, documents, maintenance.
Short answer
A correct selection starts not with a catalog but with ten groups of input data. A missed group almost always means the vendor returns the inquiry for clarification.
Do not substitute values from other projects: vacuum, thermal cycles and media usually differ even between neighbouring vessels.
Ten groups of input data
The listed groups match the input fields of the selector and the RFQ sheet on this site.
- task: new installation, replacement, glass only, component;
- mounting method: welding, existing flange, special, unknown;
- geometry: DN, free window diameter, glass outer diameter for replacement;
- pressure: working, design/maximum, vacuum, pulsations;
- temperature: minimum, operating, maximum, short-time modes;
- medium: composition and concentration, state, abrasiveness, aggressiveness;
- materials: preferences for glass, body, gaskets;
- visibility: lighting, wiper, protection;
- documents: drawing, vessel certificate, certificate requirements;
- maintenance: access, washing frequency, replacement in place.
How to use the list
Go through the groups in order and mark “unknown” where data is missing. An honest “unknown” is better than an invented value: the selector shows what to clarify, and the vendor receives a correct inquiry.
What cannot be derived from the list
The list does not turn into an engineering verdict: construction classes can be outlined, but the admissibility of the assembly is confirmed by the manufacturer with the complete data.