• Sight Glasses SSP Series are available as DIN- or ANSI-types, with sight glass window plates made of Borosili- cate acc. to DIN 7080 as per standard.
• The sturdy design bodies are made of cast steel 1.0619 (WCB), coating RAL 5005 signal-blue or stainless steel casting 1.4408 (CF8M), with resistant linings such as PFA or PFA-AS (antistatic).
• Heavy-duty, proven construction
• Maintenance-free
• Horizontal or vertical installation, flange connection acc.to ASME B16.5, CL 150
• No additional flange gaskets due to wide and chambered flange sealing surface
• Standard drip ledge indicating even minute flows
• Large sight glass opening for optimum monitoring
• Grounding connection as standard 
• FDA-conform Options 
• Metal reinforced glass plates
• Quartz glasses
• FEP glass protection sheet
• Visual flow indicator for gases (PTFE ribbon)
• Grounding cable Operation Conditions
• Temperature range from –40 °F up to +400 °F, depending on lining material
• Pressure range from 0.01 psi up to 232 psi, depending on size/pressure/temperature Testing/Marking
• Pressure- and tightness testing acc. to EN 12266-1, leakage rate A, resp. API 598
• High voltage testing of the plastic linings for freedom from pores at 35 kV
• Marking of valves on body and name plate acc. to EN 19
• Material- resp. test certificates acc. to EN 10204-3.1/2.2/2.1

Swissfluid SSP Sight Glass TDS 

https://www.swissfluid.com/en/sight_glasses_ssp_s01.htm